"""Shared model-switching logic for CLI and gateway /model commands.

Both the CLI (cli.py) and gateway (gateway/run.py) /model handlers
share the same core pipeline:

  parse flags -> alias resolution -> provider resolution ->
  credential resolution -> normalize model name ->
  metadata lookup -> build result

This module ties together the foundation layers:

- ``agent.models_dev``            -- models.dev catalog, ModelInfo, ProviderInfo
- ``hermes_cli.providers``        -- canonical provider identity + overlays
- ``hermes_cli.model_normalize``  -- per-provider name formatting

Provider switching uses the ``--provider`` flag exclusively.
No colon-based ``provider:model`` syntax — colons are reserved for
OpenRouter variant suffixes (``:free``, ``:extended``, ``:fast``).
"""

from __future__ import annotations

import logging
import re
from dataclasses import dataclass
from typing import List, NamedTuple, Optional

from hermes_cli.providers import (
    custom_provider_slug,
    determine_api_mode,
    get_label,
    is_aggregator,
    resolve_provider_full,
)
from hermes_cli.model_normalize import (
    normalize_model_for_provider,
)
from agent.models_dev import (
    ModelCapabilities,
    ModelInfo,
    get_model_capabilities,
    get_model_info,
    list_provider_models,
)

logger = logging.getLogger(__name__)


# ---------------------------------------------------------------------------
# Non-agentic model warning
# ---------------------------------------------------------------------------

_HERMES_MODEL_WARNING = (
    "Nous Research Hermes 3 & 4 models are NOT agentic and are not designed "
    "for use with Hermes Agent. They lack the tool-calling capabilities "
    "required for agent workflows. Consider using an agentic model instead "
    "(Claude, GPT, Gemini, DeepSeek, etc.)."
)

# Match only the real Nous Research Hermes 3 / Hermes 4 chat families.
# The previous substring check (`"hermes" in name.lower()`) false-positived on
# unrelated local Modelfiles like ``hermes-brain:qwen3-14b-ctx16k`` that just
# happen to carry "hermes" in their tag but are fully tool-capable.
#
# Positive examples the regex must match:
#   NousResearch/Hermes-3-Llama-3.1-70B, hermes-4-405b, openrouter/hermes3:70b
# Negative examples it must NOT match:
#   hermes-brain:qwen3-14b-ctx16k, qwen3:14b, claude-opus-4-6
_NOUS_HERMES_NON_AGENTIC_RE = re.compile(
    r"(?:^|[/:])hermes[-_ ]?[34](?:[-_.:]|$)",
    re.IGNORECASE,
)


def is_nous_hermes_non_agentic(model_name: str) -> bool:
    """Return True if *model_name* is a real Nous Hermes 3/4 chat model.

    Used to decide whether to surface the non-agentic warning at startup.
    Callers in :mod:`cli.py` and here should go through this single helper
    so the two sites don't drift.
    """
    if not model_name:
        return False
    return bool(_NOUS_HERMES_NON_AGENTIC_RE.search(model_name))


def _check_hermes_model_warning(model_name: str) -> str:
    """Return a warning string if *model_name* is a Nous Hermes 3/4 chat model."""
    if is_nous_hermes_non_agentic(model_name):
        return _HERMES_MODEL_WARNING
    return ""


# ---------------------------------------------------------------------------
# Model aliases -- short names -> (vendor, family) with NO version numbers.
# Resolved dynamically against the live models.dev catalog.
# ---------------------------------------------------------------------------

class ModelIdentity(NamedTuple):
    """Vendor slug and family prefix used for catalog resolution."""
    vendor: str
    family: str


MODEL_ALIASES: dict[str, ModelIdentity] = {
    # Anthropic
    "sonnet":    ModelIdentity("anthropic", "claude-sonnet"),
    "opus":      ModelIdentity("anthropic", "claude-opus"),
    "haiku":     ModelIdentity("anthropic", "claude-haiku"),
    "claude":    ModelIdentity("anthropic", "claude"),

    # OpenAI
    "gpt5":      ModelIdentity("openai", "gpt-5"),
    "gpt":       ModelIdentity("openai", "gpt"),
    "codex":     ModelIdentity("openai", "codex"),
    "o3":        ModelIdentity("openai", "o3"),
    "o4":        ModelIdentity("openai", "o4"),

    # Google
    "gemini":    ModelIdentity("google", "gemini"),

    # DeepSeek
    "deepseek":  ModelIdentity("deepseek", "deepseek-chat"),

    # X.AI
    "grok":      ModelIdentity("x-ai", "grok"),

    # Meta
    "llama":     ModelIdentity("meta-llama", "llama"),

    # Qwen / Alibaba
    "qwen":      ModelIdentity("qwen", "qwen"),

    # MiniMax
    "minimax":   ModelIdentity("minimax", "minimax"),

    # Nvidia
    "nemotron":  ModelIdentity("nvidia", "nemotron"),

    # Moonshot / Kimi
    "kimi":      ModelIdentity("moonshotai", "kimi"),

    # Z.AI / GLM
    "glm":       ModelIdentity("z-ai", "glm"),

    # Step Plan (StepFun)
    "step":      ModelIdentity("stepfun", "step"),

    # Xiaomi
    "mimo":      ModelIdentity("xiaomi", "mimo"),

    # Arcee
    "trinity":   ModelIdentity("arcee-ai", "trinity"),
}


# ---------------------------------------------------------------------------
# Direct aliases — exact model+provider+base_url for endpoints that aren't
# in the models.dev catalog (e.g. Ollama Cloud, local servers).
# Checked BEFORE catalog resolution.  Format:
#   alias -> (model_id, provider, base_url)
# These can also be loaded from config.yaml ``model_aliases:`` section.
# ---------------------------------------------------------------------------

class DirectAlias(NamedTuple):
    """Exact model mapping that bypasses catalog resolution."""
    model: str
    provider: str
    base_url: str


# Built-in direct aliases (can be extended via config.yaml model_aliases:)
_BUILTIN_DIRECT_ALIASES: dict[str, DirectAlias] = {}

# Merged dict (builtins + user config); populated by _load_direct_aliases()
DIRECT_ALIASES: dict[str, DirectAlias] = {}


def _load_direct_aliases() -> dict[str, DirectAlias]:
    """Load direct aliases from config.yaml ``model_aliases:`` section.

    Config format::

        model_aliases:
          qwen:
            model: "qwen3.5:397b"
            provider: custom
            base_url: "https://ollama.com/v1"
          minimax:
            model: "minimax-m2.7"
            provider: custom
            base_url: "https://ollama.com/v1"

    Also reads ``model.aliases`` (set by ``hermes config set model.aliases.xxx``)
    and converts simple string entries (``ds-flash: deepseek/deepseek-v4-flash``)
    into DirectAlias objects.  The provider is parsed from the ``provider/``
    prefix in the value; if no slash, the current provider is used.
    """
    merged = dict(_BUILTIN_DIRECT_ALIASES)
    try:
        from hermes_cli.config import load_config
        cfg = load_config()

        # --- model_aliases (dict-based format) ---
        user_aliases = cfg.get("model_aliases")
        if isinstance(user_aliases, dict):
            for name, entry in user_aliases.items():
                if not isinstance(entry, dict):
                    continue
                model = entry.get("model", "")
                provider = entry.get("provider", "custom")
                base_url = entry.get("base_url", "")
                if model:
                    merged[name.strip().lower()] = DirectAlias(
                        model=model, provider=provider, base_url=base_url,
                    )

        # --- model.aliases (string-based format, from config set) ---
        model_section = cfg.get("model", {})
        if isinstance(model_section, dict):
            simple_aliases = model_section.get("aliases")
            if isinstance(simple_aliases, dict):
                current_provider = model_section.get("provider", "")
                for name, value in simple_aliases.items():
                    if not isinstance(value, str) or not value.strip():
                        continue
                    key = name.strip().lower()
                    if key in merged:
                        continue  # don't override explicit model_aliases entries
                    val = value.strip()
                    if "/" in val:
                        provider, model = val.split("/", 1)
                    else:
                        provider = current_provider
                        model = val
                    merged[key] = DirectAlias(
                        model=model.strip(),
                        provider=provider.strip() or current_provider,
                        base_url="",
                    )
    except Exception:
        pass
    return merged


def _ensure_direct_aliases() -> None:
    """Lazy-load direct aliases on first use.

    Mutates the existing DIRECT_ALIASES dict in place rather than rebinding
    the module attribute. This keeps `from hermes_cli.model_switch import
    DIRECT_ALIASES` references valid in callers — rebinding would leave them
    pointing at a stale empty dict.
    """
    if not DIRECT_ALIASES:
        DIRECT_ALIASES.update(_load_direct_aliases())


# ---------------------------------------------------------------------------
# Result dataclasses
# ---------------------------------------------------------------------------

@dataclass
class ModelSwitchResult:
    """Result of a model switch attempt."""

    success: bool
    new_model: str = ""
    target_provider: str = ""
    provider_changed: bool = False
    api_key: str = ""
    base_url: str = ""
    api_mode: str = ""
    error_message: str = ""
    warning_message: str = ""
    provider_label: str = ""
    resolved_via_alias: str = ""
    capabilities: Optional[ModelCapabilities] = None
    model_info: Optional[ModelInfo] = None
    is_global: bool = False
# ---------------------------------------------------------------------------
# Flag parsing
# ---------------------------------------------------------------------------

def parse_model_flags(raw_args: str) -> tuple[str, str, bool, bool]:
    """Parse --provider, --global, and --refresh flags from /model command args.

    Returns (model_input, explicit_provider, is_global, force_refresh).

    Examples::

        "sonnet"                         -> ("sonnet", "", False, False)
        "sonnet --global"                -> ("sonnet", "", True, False)
        "sonnet --provider anthropic"    -> ("sonnet", "anthropic", False, False)
        "--provider my-ollama"           -> ("", "my-ollama", False, False)
        "--refresh"                      -> ("", "", False, True)
        "sonnet --provider anthropic --global" -> ("sonnet", "anthropic", True, False)
    """
    is_global = False
    explicit_provider = ""
    force_refresh = False

    # Normalize Unicode dashes (Telegram/iOS auto-converts -- to em/en dash)
    # A single Unicode dash before a flag keyword becomes "--"
    import re as _re
    raw_args = _re.sub(r'[\u2012\u2013\u2014\u2015](provider|global|refresh)', r'--\1', raw_args)

    # Extract --global
    if "--global" in raw_args:
        is_global = True
        raw_args = raw_args.replace("--global", "").strip()

    # Extract --refresh (bust the model picker disk cache before listing)
    if "--refresh" in raw_args:
        force_refresh = True
        raw_args = raw_args.replace("--refresh", "").strip()

    # Extract --provider <name>
    parts = raw_args.split()
    i = 0
    filtered: list[str] = []
    while i < len(parts):
        if parts[i] == "--provider" and i + 1 < len(parts):
            explicit_provider = parts[i + 1]
            i += 2
        else:
            filtered.append(parts[i])
            i += 1

    model_input = " ".join(filtered).strip()
    return (model_input, explicit_provider, is_global, force_refresh)


# ---------------------------------------------------------------------------
# Alias resolution
# ---------------------------------------------------------------------------

def _model_sort_key(model_id: str, prefix: str) -> tuple:
    """Sort key for model version preference.

    Extracts version numbers after the family prefix and returns a sort key
    that prefers higher versions.  Suffix tokens (``pro``, ``omni``, etc.)
    are used as tiebreakers, with common quality indicators ranked.

    Examples (with prefix ``"mimo"``)::

        mimo-v2.5-pro   → (-2.5, 0, 'pro')     # highest version wins
        mimo-v2.5       → (-2.5, 1, '')          # no suffix = lower than pro
        mimo-v2-pro     → (-2.0, 0, 'pro')
        mimo-v2-omni    → (-2.0, 1, 'omni')
        mimo-v2-flash   → (-2.0, 1, 'flash')
    """
    # Strip the prefix (and optional "/" separator for aggregator slugs)
    rest = model_id[len(prefix):]
    if rest.startswith("/"):
        rest = rest[1:]
    rest = rest.lstrip("-").strip()

    # Parse version and suffix from the remainder.
    # "v2.5-pro" → version [2.5], suffix "pro"
    # "-omni"    → version [],    suffix "omni"
    # State machine: start → in_version → between → in_suffix
    nums: list[float] = []
    suffix_buf = ""
    state = "start"
    num_buf = ""

    for ch in rest:
        if state == "start":
            if ch in "vV":
                state = "in_version"
            elif ch.isdigit():
                state = "in_version"
                num_buf += ch
            elif ch in "-_.":
                pass  # skip separators before any content
            else:
                state = "in_suffix"
                suffix_buf += ch
        elif state == "in_version":
            if ch.isdigit():
                num_buf += ch
            elif ch == ".":
                if "." in num_buf:
                    # Second dot — flush current number, start new component
                    try:
                        nums.append(float(num_buf.rstrip(".")))
                    except ValueError:
                        pass
                    num_buf = ""
                else:
                    num_buf += ch
            elif ch in "-_.":
                if num_buf:
                    try:
                        nums.append(float(num_buf.rstrip(".")))
                    except ValueError:
                        pass
                    num_buf = ""
                state = "between"
            else:
                if num_buf:
                    try:
                        nums.append(float(num_buf.rstrip(".")))
                    except ValueError:
                        pass
                    num_buf = ""
                state = "in_suffix"
                suffix_buf += ch
        elif state == "between":
            if ch.isdigit():
                state = "in_version"
                num_buf = ch
            elif ch in "vV":
                state = "in_version"
            elif ch in "-_.":
                pass
            else:
                state = "in_suffix"
                suffix_buf += ch
        elif state == "in_suffix":
            suffix_buf += ch

    # Flush remaining buffer (strip trailing dots — "5.4." → "5.4")
    if num_buf and state == "in_version":
        try:
            nums.append(float(num_buf.rstrip(".")))
        except ValueError:
            pass

    suffix = suffix_buf.lower().strip("-_.")
    suffix = suffix.strip()

    # Negate versions so higher → sorts first
    version_key = tuple(-n for n in nums)

    # Suffix quality ranking: pro/max > (no suffix) > omni/flash/mini/lite
    # Lower number = preferred
    _SUFFIX_RANK = {"pro": 0, "max": 0, "plus": 0, "turbo": 0}
    suffix_rank = _SUFFIX_RANK.get(suffix, 1)

    return version_key + (suffix_rank, suffix)


def resolve_alias(
    raw_input: str,
    current_provider: str,
) -> Optional[tuple[str, str, str]]:
    """Resolve a short alias against the current provider's catalog.

    Looks up *raw_input* in :data:`MODEL_ALIASES`, then searches the
    current provider's models.dev catalog for the model whose ID starts
    with ``vendor/family`` (or just ``family`` for non-aggregator
    providers) and has the **highest version**.

    Returns:
        ``(provider, resolved_model_id, alias_name)`` if a match is
        found on the current provider, or ``None`` if the alias doesn't
        exist or no matching model is available.
    """
    key = raw_input.strip().lower()

    # Check direct aliases first (exact model+provider+base_url mappings)
    _ensure_direct_aliases()
    direct = DIRECT_ALIASES.get(key)
    if direct is not None:
        return (direct.provider, direct.model, key)

    # Reverse lookup: match by model ID so full names (e.g. "kimi-k2.5",
    # "glm-4.7") route through direct aliases instead of falling through
    # to the catalog/OpenRouter.
    for alias_name, da in DIRECT_ALIASES.items():
        if da.model.lower() == key:
            return (da.provider, da.model, alias_name)

    identity = MODEL_ALIASES.get(key)
    if identity is None:
        return None

    vendor, family = identity

    # Build catalog from models.dev, then merge in static _PROVIDER_MODELS
    # entries that models.dev may be missing (e.g. newly added models not
    # yet synced to the registry).
    catalog = list_provider_models(current_provider)
    try:
        from hermes_cli.models import _PROVIDER_MODELS
        static = _PROVIDER_MODELS.get(current_provider, [])
        if static:
            seen = {m.lower() for m in catalog}
            for m in static:
                if m.lower() not in seen:
                    catalog.append(m)
    except Exception:
        pass

    # For aggregators, models are vendor/model-name format
    aggregator = is_aggregator(current_provider)

    if aggregator:
        prefix = f"{vendor}/{family}".lower()
        matches = [
            mid for mid in catalog
            if mid.lower().startswith(prefix)
        ]
    else:
        family_lower = family.lower()
        matches = [
            mid for mid in catalog
            if mid.lower().startswith(family_lower)
        ]

    if not matches:
        return None

    # Sort by version descending — prefer the latest/highest version
    prefix_for_sort = f"{vendor}/{family}" if aggregator else family
    matches.sort(key=lambda m: _model_sort_key(m, prefix_for_sort))
    return (current_provider, matches[0], key)


def get_authenticated_provider_slugs(
    current_provider: str = "",
    user_providers: dict = None,
    custom_providers: list | None = None,
) -> list[str]:
    """Return slugs of providers that have credentials.

    Uses ``list_authenticated_providers()`` which is backed by the models.dev
    in-memory cache (1 hr TTL) — no extra network cost.
    """
    try:
        providers = list_authenticated_providers(
            current_provider=current_provider,
            user_providers=user_providers,
            custom_providers=custom_providers,
            max_models=0,
        )
        return [p["slug"] for p in providers]
    except Exception:
        return []


def _resolve_alias_fallback(
    raw_input: str,
    authenticated_providers: list[str] = (),
) -> Optional[tuple[str, str, str]]:
    """Try to resolve an alias on the user's authenticated providers.

    Falls back to ``("openrouter", "nous")`` only when no authenticated
    providers are supplied (backwards compat for non-interactive callers).
    """
    providers = authenticated_providers or ("openrouter", "nous")
    for provider in providers:
        result = resolve_alias(raw_input, provider)
        if result is not None:
            return result
    return None


def resolve_display_context_length(
    model: str,
    provider: str,
    base_url: str = "",
    api_key: str = "",
    model_info: Optional[ModelInfo] = None,
    custom_providers: list | None = None,
    config_context_length: int | None = None,
) -> Optional[int]:
    """Resolve the context length to show in /model output.

    models.dev reports per-vendor context (e.g. gpt-5.5 = 1.05M on openai)
    but provider-enforced limits can be lower (e.g. Codex OAuth caps the
    same slug at 272k). The authoritative source is
    ``agent.model_metadata.get_model_context_length`` which already knows
    about Codex OAuth, Copilot, Nous, and falls back to models.dev for the
    rest.

    When ``custom_providers`` is provided, per-model ``context_length``
    overrides from ``custom_providers[].models.<id>.context_length`` are
    honored — this closes #15779 where ``/model`` switch ignored user-set
    overrides.

    Prefer the provider-aware value; fall back to ``model_info.context_window``
    only if the resolver returns nothing.
    """
    try:
        from agent.model_metadata import get_model_context_length
        ctx = get_model_context_length(
            model,
            base_url=base_url or "",
            api_key=api_key or "",
            provider=provider or None,
            custom_providers=custom_providers,
            config_context_length=config_context_length,
        )
        if ctx:
            return int(ctx)
    except Exception:
        pass
    if model_info is not None and model_info.context_window:
        return int(model_info.context_window)
    return None


# ---------------------------------------------------------------------------
# Core model-switching pipeline
# ---------------------------------------------------------------------------

def switch_model(
    raw_input: str,
    current_provider: str,
    current_model: str,
    current_base_url: str = "",
    current_api_key: str = "",
    is_global: bool = False,
    explicit_provider: str = "",
    user_providers: dict = None,
    custom_providers: list | None = None,
) -> ModelSwitchResult:
    """Core model-switching pipeline shared between CLI and gateway.

    Resolution chain:

      If --provider given:
        a. Resolve provider via resolve_provider_full()
        b. Resolve credentials
        c. If model given, resolve alias on target provider or use as-is
        d. If no model, auto-detect from endpoint

      If no --provider:
        a. Try alias resolution on current provider
        b. If alias exists but not on current provider -> fallback
        c. On aggregator, try vendor/model slug conversion
        d. Aggregator catalog search
        e. detect_provider_for_model() as last resort
        f. Resolve credentials
        g. Normalize model name for target provider

      Finally:
        h. Get full model metadata from models.dev
        i. Build result

    Args:
        raw_input: The model name (after flag parsing).
        current_provider: The currently active provider.
        current_model: The currently active model name.
        current_base_url: The currently active base URL.
        current_api_key: The currently active API key.
        is_global: Whether to persist the switch.
        explicit_provider: From --provider flag (empty = no explicit provider).
        user_providers: The ``providers:`` dict from config.yaml (for user endpoints).
        custom_providers: The ``custom_providers:`` list from config.yaml.

    Returns:
        ModelSwitchResult with all information the caller needs.
    """
    from hermes_cli.models import (
        copilot_model_api_mode,
        detect_provider_for_model,
        validate_requested_model,
        opencode_model_api_mode,
    )
    from hermes_cli.runtime_provider import resolve_runtime_provider

    resolved_alias = ""
    new_model = raw_input.strip()
    target_provider = current_provider

    # =================================================================
    # PATH A: Explicit --provider given
    # =================================================================
    if explicit_provider:
        # Resolve the provider
        pdef = resolve_provider_full(
            explicit_provider,
            user_providers,
            custom_providers,
        )
        if pdef is None:
            _switch_err = (
                f"Unknown provider '{explicit_provider}'. "
                f"Check 'hermes model' for available providers, or define it "
                f"in config.yaml under 'providers:'."
            )
            # Check for common config issues that cause provider resolution failures
            try:
                from hermes_cli.config import validate_config_structure
                _cfg_issues = validate_config_structure()
                if _cfg_issues:
                    _switch_err += "\n\nRun 'hermes doctor' — config issues detected:"
                    for _ci in _cfg_issues[:3]:
                        _switch_err += f"\n  • {_ci.message}"
            except Exception:
                pass
            return ModelSwitchResult(
                success=False,
                is_global=is_global,
                error_message=_switch_err,
            )

        target_provider = pdef.id

        # Guard against silent aggregator hops. A vendor name like bare
        # "openai" is an alias that resolves to an aggregator ("openrouter").
        # If the user explicitly asked for that vendor but the aggregator it
        # routes to has no credentials, do NOT silently switch them onto an
        # unauthed endpoint (the classic HTTP 401 "Missing Authentication
        # header"). Point them at the real direct provider instead.
        from hermes_cli.models import _AGGREGATOR_PROVIDERS as _AGG_PROVIDERS
        from hermes_cli.providers import ALIASES as _PROVIDER_ALIAS_TABLE
        _explicit_norm = explicit_provider.strip().lower()
        _alias_target = _PROVIDER_ALIAS_TABLE.get(_explicit_norm)
        if (
            _alias_target
            and _alias_target == target_provider
            and target_provider != _explicit_norm
            and target_provider in _AGG_PROVIDERS
        ):
            _authed = get_authenticated_provider_slugs(
                current_provider=current_provider,
                user_providers=user_providers,
                custom_providers=custom_providers,
            )
            if target_provider not in _authed:
                _suggestions = [
                    s for s in _authed
                    if s.startswith(_explicit_norm) and s != _explicit_norm
                ]
                _hint = (
                    f" Did you mean: {', '.join(_suggestions)}?"
                    if _suggestions else ""
                )
                return ModelSwitchResult(
                    success=False,
                    target_provider=target_provider,
                    provider_label=pdef.name,
                    is_global=is_global,
                    error_message=(
                        f"Provider '{_explicit_norm}' is an alias that routes "
                        f"through {get_label(target_provider)}, which "
                        f"has no credentials configured.{_hint}"
                    ),
                )

        # If no model specified, try auto-detect from endpoint
        if not new_model:
            if pdef.base_url:
                from hermes_cli.runtime_provider import _auto_detect_local_model
                detected = _auto_detect_local_model(pdef.base_url)
                if detected:
                    new_model = detected
                else:
                    return ModelSwitchResult(
                        success=False,
                        target_provider=target_provider,
                        provider_label=pdef.name,
                        is_global=is_global,
                        error_message=(
                            f"No model detected on {pdef.name} ({pdef.base_url}). "
                            f"Specify the model explicitly: /model <model-name> --provider {explicit_provider}"
                        ),
                    )
            else:
                return ModelSwitchResult(
                    success=False,
                    target_provider=target_provider,
                    provider_label=pdef.name,
                    is_global=is_global,
                    error_message=(
                        f"Provider '{pdef.name}' has no base URL configured. "
                        f"Specify a model: /model <model-name> --provider {explicit_provider}"
                    ),
                )

        # Resolve alias on the TARGET provider
        alias_result = resolve_alias(new_model, target_provider)
        if alias_result is not None:
            _, new_model, resolved_alias = alias_result

    # =================================================================
    # PATH B: No explicit provider — resolve from model input
    # =================================================================
    else:
        # --- Step a: Try alias resolution on current provider ---
        alias_result = resolve_alias(raw_input, current_provider)

        if alias_result is not None:
            target_provider, new_model, resolved_alias = alias_result
            logger.debug(
                "Alias '%s' resolved to %s on %s",
                resolved_alias, new_model, target_provider,
            )
        else:
            # --- Step b: Alias exists but not on current provider -> fallback ---
            key = raw_input.strip().lower()
            if key in MODEL_ALIASES:
                authed = get_authenticated_provider_slugs(
                    current_provider=current_provider,
                    user_providers=user_providers,
                    custom_providers=custom_providers,
                )
                fallback_result = _resolve_alias_fallback(raw_input, authed)
                if fallback_result is not None:
                    target_provider, new_model, resolved_alias = fallback_result
                    logger.debug(
                        "Alias '%s' resolved via fallback to %s on %s",
                        resolved_alias, new_model, target_provider,
                    )
                else:
                    identity = MODEL_ALIASES[key]
                    return ModelSwitchResult(
                        success=False,
                        is_global=is_global,
                        error_message=(
                            f"Alias '{key}' maps to {identity.vendor}/{identity.family} "
                            f"but no matching model was found in any provider catalog. "
                            f"Try specifying the full model name."
                        ),
                    )
            else:
                # --- Step c: On aggregator, convert vendor:model to vendor/model ---
                # Only convert when there's no slash — a slash means the name
                # is already in vendor/model format and the colon is a variant
                # tag (:free, :extended, :fast) that must be preserved.
                colon_pos = raw_input.find(":")
                if colon_pos > 0 and "/" not in raw_input and is_aggregator(current_provider):
                    left = raw_input[:colon_pos].strip().lower()
                    right = raw_input[colon_pos + 1:].strip()
                    if left and right:
                        # Colons become slashes for aggregator slugs
                        new_model = f"{left}/{right}"
                        logger.debug(
                            "Converted vendor:model '%s' to aggregator slug '%s'",
                            raw_input, new_model,
                        )

        # --- Step d: Aggregator catalog search ---
        # Track whether the live catalog of the CURRENT provider resolved the
        # model — if so, step e must not second-guess and switch providers.
        # Critical for flat-namespace resellers like opencode-go / opencode-zen
        # whose live /v1/models returns bare IDs (e.g. "deepseek-v4-flash") that
        # coincidentally match entries in native providers' static catalogs.
        resolved_in_current_catalog = False
        if is_aggregator(target_provider) and not resolved_alias:
            catalog = list_provider_models(target_provider)
            if catalog:
                new_model_lower = new_model.lower()
                for mid in catalog:
                    if mid.lower() == new_model_lower:
                        new_model = mid
                        resolved_in_current_catalog = True
                        break
                else:
                    for mid in catalog:
                        if "/" in mid:
                            _, bare = mid.split("/", 1)
                            if bare.lower() == new_model_lower:
                                new_model = mid
                                resolved_in_current_catalog = True
                                break

        # --- Step e: detect_provider_for_model() as last resort ---
        _base = current_base_url or ""
        is_custom = current_provider in {"custom", "local"} or (
            "localhost" in _base or "127.0.0.1" in _base
        )

        if (
            target_provider == current_provider
            and not is_custom
            and not resolved_alias
            and not resolved_in_current_catalog
        ):
            detected = detect_provider_for_model(new_model, current_provider)
            if detected:
                target_provider, new_model = detected

    # =================================================================
    # COMMON PATH: Resolve credentials, normalize, get metadata
    # =================================================================

    provider_changed = target_provider != current_provider
    provider_label = get_label(target_provider)
    if target_provider.startswith("custom:"):
        custom_pdef = resolve_provider_full(
            target_provider,
            user_providers,
            custom_providers,
        )
        if custom_pdef is not None:
            provider_label = custom_pdef.name

    # --- Resolve credentials ---
    api_key = current_api_key
    base_url = current_base_url
    api_mode = ""

    if provider_changed or explicit_provider:
        import os
        # User-config providers (providers.<name> in config.yaml) carry their
        # own base_url + transport + key reference. resolve_runtime_provider()
        # resolves by provider NAME and doesn't know user-config slugs (e.g. a
        # block named "openai"), so it would re-resolve from scratch and fail
        # or hop to an aggregator. Use the pdef's endpoint directly instead.
        _user_pdef = None
        if explicit_provider and user_providers:
            from hermes_cli.providers import resolve_user_provider as _ruser
            _user_pdef = _ruser(explicit_provider.strip().lower(), user_providers)
            if _user_pdef is None:
                _user_pdef = _ruser(target_provider, user_providers)
        if _user_pdef is not None and _user_pdef.base_url:
            _ucfg = (user_providers or {}).get(explicit_provider.strip().lower()) \
                or (user_providers or {}).get(target_provider) or {}
            _ukey = str(_ucfg.get("api_key", "") or "").strip()
            if _ukey.startswith("${") and _ukey.endswith("}"):
                _ukey = os.environ.get(_ukey[2:-1], "").strip()
            if not _ukey:
                _kenv = str(_ucfg.get("key_env", "") or "").strip()
                if _kenv:
                    _ukey = os.environ.get(_kenv, "").strip()
            try:
                runtime = resolve_runtime_provider(
                    requested=target_provider,
                    explicit_api_key=_ukey or None,
                    explicit_base_url=_user_pdef.base_url,
                    target_model=new_model,
                )
                api_key = runtime.get("api_key", "") or _ukey
                base_url = runtime.get("base_url", "") or _user_pdef.base_url
                api_mode = runtime.get("api_mode", "")
            except Exception:
                api_key = _ukey
                base_url = _user_pdef.base_url
                api_mode = ""
        else:
            try:
                runtime = resolve_runtime_provider(
                    requested=target_provider,
                    target_model=new_model,
                )
                api_key = runtime.get("api_key", "")
                base_url = runtime.get("base_url", "")
                api_mode = runtime.get("api_mode", "")
            except Exception as e:
                return ModelSwitchResult(
                    success=False,
                    target_provider=target_provider,
                    provider_label=provider_label,
                    is_global=is_global,
                    error_message=(
                        f"Could not resolve credentials for provider "
                        f"'{provider_label}': {e}"
                    ),
                )
    else:
        try:
            runtime = resolve_runtime_provider(
                requested=current_provider,
                target_model=new_model,
            )
            # If resolution fell through to "custom" (e.g. named custom provider like
            # "ollama-launch" that resolve_runtime_provider doesn't know), keep existing
            # credentials. Otherwise use the resolved values (picks up credential rotation,
            # base_url adjustments for OpenCode, etc.).
            api_key = runtime.get("api_key", "")
            base_url = runtime.get("base_url", "")
            api_mode = runtime.get("api_mode", "")
        except Exception:
            pass

    # --- Direct alias override: use exact base_url from the alias if set ---
    if resolved_alias:
        _ensure_direct_aliases()
        _da = DIRECT_ALIASES.get(resolved_alias)
        if _da is not None and _da.base_url:
            base_url = _da.base_url
            api_mode = ""  # clear so determine_api_mode re-detects from URL
            if not api_key:
                api_key = "no-key-required"

    # --- Normalize model name for target provider ---
    new_model = normalize_model_for_provider(new_model, target_provider)

    # --- Validate ---
    try:
        validation = validate_requested_model(
            new_model,
            target_provider,
            api_key=api_key,
            base_url=base_url,
            api_mode=api_mode or None,
        )
    except Exception as e:
        validation = {
            "accepted": False,
            "persist": False,
            "recognized": False,
            "message": f"Could not validate `{new_model}`: {e}",
        }

    # Override rejection if model is in the user's saved provider config.
    # API /v1/models may not list cloud/aliased models even though the server supports them.
    if not validation.get("accepted"):
        override = False
        if user_providers:
            # user_providers is a dict: {provider_slug: config_dict}
            for slug, cfg in user_providers.items():
                if slug == target_provider:
                    cfg_models = cfg.get("models", {})
                    # Direct membership works for dict (keys) and list (strings)
                    if new_model in cfg_models:
                        override = True
                        break
                    # Also accept if models is a list of dicts with 'name' field
                    if isinstance(cfg_models, list):
                        if any(m.get("name") == new_model for m in cfg_models if isinstance(m, dict)):
                            override = True
                            break
        # Also check custom_providers list — models declared there should be accepted
        # even if the remote /v1/models endpoint doesn't list them.
        if not override and custom_providers and isinstance(custom_providers, list):
            for entry in custom_providers:
                if not isinstance(entry, dict):
                    continue
                # Match by provider slug (custom:<name>) or by base_url
                entry_name = entry.get("name", "")
                entry_slug = f"custom:{entry_name}" if entry_name else ""
                entry_url = entry.get("base_url", "")
                if entry_slug == target_provider or entry_url == base_url:
                    # Check if the requested model matches the entry's model
                    entry_model = entry.get("model", "")
                    entry_models = entry.get("models", {})
                    if new_model == entry_model:
                        override = True
                        break
                    if isinstance(entry_models, dict) and new_model in entry_models:
                        override = True
                        break
        if override:
            validation = {"accepted": True, "persist": True, "recognized": False, "message": validation.get("message", "")}
        else:
            msg = validation.get("message", "Invalid model")
            return ModelSwitchResult(
                success=False,
                new_model=new_model,
                target_provider=target_provider,
                provider_label=provider_label,
                is_global=is_global,
                error_message=msg,
            )

    # Apply auto-correction if validation found a closer match
    if validation.get("corrected_model"):
        new_model = validation["corrected_model"]

    # --- Copilot api_mode override ---
    if target_provider in {"copilot", "github-copilot"}:
        api_mode = copilot_model_api_mode(new_model, api_key=api_key)

    # --- OpenCode api_mode override ---
    if target_provider in {"opencode-zen", "opencode-go", "opencode"}:
        api_mode = opencode_model_api_mode(target_provider, new_model)

    # --- Determine api_mode if not already set ---
    if not api_mode:
        api_mode = determine_api_mode(target_provider, base_url)

    # OpenCode base URLs end with /v1 for OpenAI-compatible models, but the
    # Anthropic SDK prepends its own /v1/messages to the base_url.  Strip the
    # trailing /v1 so the SDK constructs the correct path (e.g.
    # https://opencode.ai/zen/go/v1/messages instead of .../v1/v1/messages).
    # Mirrors the same logic in hermes_cli.runtime_provider.resolve_runtime_provider;
    # without it, /model switches into an anthropic_messages-routed OpenCode
    # model (e.g. `/model minimax-m2.7` on opencode-go, `/model claude-sonnet-4-6`
    # on opencode-zen) hit a double /v1 and returned OpenCode's website 404 page.
    if (
        api_mode == "anthropic_messages"
        and target_provider in {"opencode-zen", "opencode-go"}
        and isinstance(base_url, str)
        and base_url
    ):
        base_url = re.sub(r"/v1/?$", "", base_url)

    # --- Get capabilities (legacy) ---
    capabilities = get_model_capabilities(target_provider, new_model)

    # --- Get full model info from models.dev ---
    model_info = get_model_info(target_provider, new_model)

    # --- Collect warnings ---
    warnings: list[str] = []
    if validation.get("message"):
        warnings.append(validation["message"])
    hermes_warn = _check_hermes_model_warning(new_model)
    if hermes_warn:
        warnings.append(hermes_warn)

    # --- Build result ---
    return ModelSwitchResult(
        success=True,
        new_model=new_model,
        target_provider=target_provider,
        provider_changed=provider_changed,
        api_key=api_key,
        base_url=base_url,
        api_mode=api_mode,
        warning_message=" | ".join(warnings) if warnings else "",
        provider_label=provider_label,
        resolved_via_alias=resolved_alias,
        capabilities=capabilities,
        model_info=model_info,
        is_global=is_global,
    )


# ---------------------------------------------------------------------------
# Authenticated providers listing (for /model no-args display)
# ---------------------------------------------------------------------------

# Process-level guard so the picker prewarm thread is spawned at most once per
# process — mirrors run_agent's _openrouter_prewarm_done. Without a guard a
# long-lived process (or repeated triggers) would leak one OS thread per call.
import threading as _threading  # noqa: E402

_picker_prewarm_done = _threading.Event()


def prewarm_picker_cache_async() -> Optional["_threading.Thread"]:
    """Warm the provider-models disk cache in a background daemon thread.

    The no-args ``/model`` picker calls ``list_authenticated_providers()``,
    which fetches each authenticated provider's live ``/v1/models`` list on a
    cold/stale cache. Those fetches are independent HTTP round-trips but run
    serially, so the first ``/model`` open in a session (or any open after the
    1h cache TTL expires) blocks ~1-2s on the user's critical path.

    This pre-warms that exact path off-thread during idle session time: it
    runs ``list_authenticated_providers()`` once, which populates
    ``provider_models_cache.json`` for every authed provider. By the time the
    user types ``/model``, the picker hits the warm disk cache and renders in
    ~100ms.

    Fire-and-forget. Process-level Event guard ensures it runs at most once.
    Fully exception-isolated — a slow or offline provider can never affect the
    session. Returns the spawned thread (for tests) or None if already warmed.
    """
    if _picker_prewarm_done.is_set():
        return None
    _picker_prewarm_done.set()

    def _warm() -> None:
        try:
            from hermes_cli.inventory import load_picker_context

            ctx = load_picker_context()
            # Calling this is what populates cached_provider_model_ids() ->
            # provider_models_cache.json for each authed provider. We discard
            # the result; the side effect (warm disk cache) is the point.
            list_authenticated_providers(
                current_provider=ctx.current_provider,
                current_base_url=ctx.current_base_url,
                current_model=ctx.current_model,
                user_providers=ctx.user_providers,
                custom_providers=ctx.custom_providers,
                max_models=50,
            )
        except Exception:
            # Best-effort warmup — never surface errors into the session.
            logger.debug("picker cache prewarm failed", exc_info=True)

    t = _threading.Thread(target=_warm, daemon=True, name="picker-cache-prewarm")
    t.start()
    return t


def list_authenticated_providers(
    current_provider: str = "",
    current_base_url: str = "",
    user_providers: dict = None,
    custom_providers: list | None = None,
    max_models: int = 8,
    current_model: str = "",
) -> List[dict]:
    """Detect which providers have credentials and list their curated models.

    Uses the curated model lists from hermes_cli/models.py (OPENROUTER_MODELS,
    _PROVIDER_MODELS) — NOT the full models.dev catalog.  These are hand-picked
    agentic models that work well as agent backends.

    Returns a list of dicts, each with:
      - slug: str — the --provider value to use
      - name: str — display name
      - is_current: bool
      - is_user_defined: bool
      - models: list[str] — curated model IDs (up to max_models)
      - total_models: int — total curated count
      - source: str — "built-in", "models.dev", "user-config"

    Only includes providers that have API keys set or are user-defined endpoints.
    """
    import os
    from agent.models_dev import (
        PROVIDER_TO_MODELS_DEV,
        fetch_models_dev,
        get_provider_info as _mdev_pinfo,
    )
    from hermes_cli.auth import PROVIDER_REGISTRY
    from hermes_cli.models import (
        OPENROUTER_MODELS, _PROVIDER_MODELS,
        _MODELS_DEV_PREFERRED, _merge_with_models_dev, cached_provider_model_ids,
        get_curated_nous_model_ids,
    )

    results: List[dict] = []
    seen_slugs: set = set()  # lowercase-normalized to catch case variants (#9545)
    seen_mdev_ids: set = set()  # prevent duplicate entries for aliases (e.g. kimi-coding + kimi-coding-cn)
    # Effective base URLs of every built-in row we emit (normalized lower+rstrip).
    # Section 4 uses this to hide ``custom_providers`` entries that point at the
    # same endpoint as a built-in (e.g. a user-defined "my-dashscope" on
    # https://coding-intl.dashscope.aliyuncs.com/v1 collides with the built-in
    # alibaba-coding-plan row when DASHSCOPE_API_KEY is present). Fixes #16970.
    _builtin_endpoints: set = set()

    def _norm_url(url: str) -> str:
        return str(url or "").strip().rstrip("/").lower()

    def _record_builtin_endpoint(slug: str) -> None:
        """Record the effective base URL for a built-in provider row.

        Prefers the live env-override (e.g. DASHSCOPE_BASE_URL) over the
        static inference_base_url so the dedup matches what a user typing
        that URL into custom_providers would actually hit."""
        try:
            from hermes_cli.auth import PROVIDER_REGISTRY as _reg
        except Exception:
            return
        pcfg = _reg.get(slug)
        if not pcfg:
            return
        url = ""
        if getattr(pcfg, "base_url_env_var", ""):
            url = os.environ.get(pcfg.base_url_env_var, "") or ""
        if not url:
            url = getattr(pcfg, "inference_base_url", "") or ""
        normed = _norm_url(url)
        if normed:
            _builtin_endpoints.add(normed)

    def _has_fast_aws_sdk_signal() -> bool:
        """Return True when explicit AWS auth config is present.

        This intentionally avoids botocore's full credential chain. Provider
        picker/model-switch discovery can run for non-Bedrock providers, and
        botocore may otherwise probe EC2 IMDS (169.254.169.254) on local
        machines before returning no credentials.
        """
        if os.environ.get("AWS_BEARER_TOKEN_BEDROCK", "").strip():
            return True
        if (
            os.environ.get("AWS_ACCESS_KEY_ID", "").strip()
            and os.environ.get("AWS_SECRET_ACCESS_KEY", "").strip()
        ):
            return True
        return any(
            os.environ.get(name, "").strip()
            for name in (
                "AWS_PROFILE",
                "AWS_CONTAINER_CREDENTIALS_RELATIVE_URI",
                "AWS_CONTAINER_CREDENTIALS_FULL_URI",
                "AWS_WEB_IDENTITY_TOKEN_FILE",
            )
        )

    def _has_aws_sdk_creds_for_listing(slug: str) -> bool:
        """Credential check for AWS SDK providers in non-runtime discovery."""
        slug_norm = str(slug or "").strip().lower()
        current_norm = str(current_provider or "").strip().lower()
        if _has_fast_aws_sdk_signal():
            return True
        if slug_norm != current_norm:
            return False
        try:
            from agent.bedrock_adapter import has_aws_credentials
            return bool(has_aws_credentials())
        except Exception:
            return False

    data = fetch_models_dev()

    # Build curated model lists keyed by hermes provider ID
    curated: dict[str, list[str]] = dict(_PROVIDER_MODELS)
    curated["openrouter"] = [mid for mid, _ in OPENROUTER_MODELS]
    # "nous" pulls from the remote model-catalog manifest published at
    # https://hermes-agent.nousresearch.com/docs/api/model-catalog.json so
    # newly added Portal models surface in the /model picker without
    # requiring a Hermes release. Falls back to the in-repo
    # _PROVIDER_MODELS["nous"] snapshot when the manifest is unreachable.
    curated["nous"] = get_curated_nous_model_ids()
    # Ollama Cloud uses dynamic discovery (no static curated list)
    if "ollama-cloud" not in curated:
        from hermes_cli.models import fetch_ollama_cloud_models
        curated["ollama-cloud"] = fetch_ollama_cloud_models()
    # LM Studio has no static catalog — probe its native /api/v1/models
    # endpoint live so the picker reflects whatever the user has loaded.
    # Base URL precedence: LM_BASE_URL env var > active config's base_url
    # (when current provider is lmstudio) > 127.0.0.1 default.
    # On auth rejection or unreachable server, fall back to the caller-supplied
    # current model so the picker still shows something when offline / mis-keyed.
    if "lmstudio" not in curated and (
        os.environ.get("LM_API_KEY") or os.environ.get("LM_BASE_URL") or current_provider.strip().lower() == "lmstudio"
    ):
        from hermes_cli.models import fetch_lmstudio_models
        from hermes_cli.auth import AuthError
        is_current_lmstudio = current_provider.strip().lower() == "lmstudio"
        lm_base = (
            os.environ.get("LM_BASE_URL")
            or (current_base_url if is_current_lmstudio and current_base_url else None)
            or "http://127.0.0.1:1234/v1"
        )
        try:
            live = fetch_lmstudio_models(
                api_key=os.environ.get("LM_API_KEY", ""),
                base_url=lm_base,
                timeout=1.5, # Smaller timeout for picker
            )
        except AuthError:
            live = []
        if not live and is_current_lmstudio and current_model:
            live = [current_model]
        curated["lmstudio"] = live

    # --- 1. Check Hermes-mapped providers ---
    from hermes_cli.models import _AGGREGATOR_PROVIDERS as _AGG_PROVIDERS
    from hermes_cli.providers import ALIASES as _PROVIDER_ALIAS_TABLE
    for hermes_id, mdev_id in PROVIDER_TO_MODELS_DEV.items():
        # Skip vendor names that are merely aliases routing through an
        # aggregator (e.g. bare "openai" → "openrouter"). These are NOT
        # directly-routable providers: emitting them as their own picker
        # row produces a phantom entry that, when selected, resolves via
        # resolve_provider_full() to the aggregator (OpenRouter) — silently
        # switching a user off their real provider onto an endpoint they
        # may have no key for (HTTP 401). The user's real provider (e.g.
        # openai-api, or a providers.openai config row) covers this vendor.
        _alias_target = _PROVIDER_ALIAS_TABLE.get(hermes_id)
        if (
            _alias_target
            and _alias_target != hermes_id
            and _alias_target in _AGG_PROVIDERS
        ):
            continue
        # Skip aliases that map to the same models.dev provider (e.g.
        # kimi-coding and kimi-coding-cn both → kimi-for-coding).
        # The first one with valid credentials wins (#10526).
        if mdev_id in seen_mdev_ids:
            continue
        pdata = data.get(mdev_id)
        if not isinstance(pdata, dict):
            continue

        # Prefer auth.py PROVIDER_REGISTRY for env var names — it's our
        # source of truth.  models.dev can have wrong mappings (e.g.
        # minimax-cn → MINIMAX_API_KEY instead of MINIMAX_CN_API_KEY).
        pconfig = PROVIDER_REGISTRY.get(hermes_id)
        # Skip non-API-key auth providers here — they are handled in
        # section 2 (HERMES_OVERLAYS) with proper auth store checking.
        if pconfig and pconfig.auth_type != "api_key":
            continue
        if pconfig and pconfig.api_key_env_vars:
            env_vars = list(pconfig.api_key_env_vars)
        else:
            env_vars = pdata.get("env", [])
            if not isinstance(env_vars, list):
                continue

        # Check if any env var is set
        has_creds = any(os.environ.get(ev) for ev in env_vars)
        if not has_creds:
            try:
                from hermes_cli.auth import _load_auth_store
                store = _load_auth_store()
                if store and store.get("credential_pool", {}).get(hermes_id):
                    has_creds = True
            except Exception:
                pass
        if not has_creds:
            continue

        # Unified pathway: route through cached_provider_model_ids() so the
        # /model picker sees the SAME list `hermes model` would build, with
        # disk caching to keep the picker open snappy. Falls back to the
        # curated static list when the live fetcher returns nothing.
        model_ids = cached_provider_model_ids(hermes_id)
        if not model_ids:
            model_ids = curated.get(hermes_id, [])
            if hermes_id in _MODELS_DEV_PREFERRED:
                model_ids = _merge_with_models_dev(hermes_id, model_ids)
        total = len(model_ids)
        top = model_ids[:max_models]

        slug = hermes_id
        pinfo = _mdev_pinfo(mdev_id)
        display_name = pinfo.name if pinfo else mdev_id

        results.append({
            "slug": slug,
            "name": display_name,
            "is_current": slug == current_provider or mdev_id == current_provider,
            "is_user_defined": False,
            "models": top,
            "total_models": total,
            "source": "built-in",
        })
        seen_slugs.add(slug.lower())
        seen_mdev_ids.add(mdev_id)
        _record_builtin_endpoint(slug)

    # --- 2. Check Hermes-only providers (nous, openai-codex, copilot, opencode-go) ---
    from hermes_cli.providers import HERMES_OVERLAYS
    from hermes_cli.auth import PROVIDER_REGISTRY as _auth_registry

    # Build reverse mapping: models.dev ID → Hermes provider ID.
    # HERMES_OVERLAYS keys may be models.dev IDs (e.g. "github-copilot")
    # while _PROVIDER_MODELS and config.yaml use Hermes IDs ("copilot").
    _mdev_to_hermes = {v: k for k, v in PROVIDER_TO_MODELS_DEV.items()}

    for pid, overlay in HERMES_OVERLAYS.items():
        if pid.lower() in seen_slugs:
            continue

        # Resolve Hermes slug — e.g. "github-copilot" → "copilot"
        hermes_slug = _mdev_to_hermes.get(pid, pid)
        if hermes_slug.lower() in seen_slugs:
            continue

        # Check if credentials exist
        has_creds = False
        if overlay.auth_type == "aws_sdk":
            has_creds = _has_aws_sdk_creds_for_listing(hermes_slug)
        elif overlay.extra_env_vars:
            has_creds = any(os.environ.get(ev) for ev in overlay.extra_env_vars)
        # Also check api_key_env_vars from PROVIDER_REGISTRY for api_key auth_type
        if not has_creds and overlay.auth_type == "api_key":
            for _key in (pid, hermes_slug):
                pcfg = _auth_registry.get(_key)
                if pcfg and pcfg.api_key_env_vars:
                    if any(os.environ.get(ev) for ev in pcfg.api_key_env_vars):
                        has_creds = True
                        break
        # Check auth store and credential pool for non-env-var credentials.
        # This applies to OAuth providers AND api_key providers that also
        # support OAuth (e.g. anthropic supports both API key and Claude Code
        # OAuth via external credential files).
        if not has_creds:
            try:
                from hermes_cli.auth import _load_auth_store
                store = _load_auth_store()
                providers_store = store.get("providers", {})
                if store and (pid in providers_store or hermes_slug in providers_store):
                    has_creds = True
            except Exception as exc:
                logger.debug("Auth store check failed for %s: %s", pid, exc)
        # Fallback: check the credential pool with full auto-seeding.
        # This catches credentials that exist in external stores (e.g.
        # Codex CLI ~/.codex/auth.json) which _seed_from_singletons()
        # imports on demand but aren't in the raw auth.json yet.
        if not has_creds:
            try:
                from agent.credential_pool import load_pool
                pool = load_pool(hermes_slug)
                if pool.has_credentials():
                    has_creds = True
            except Exception as exc:
                logger.debug("Credential pool check failed for %s: %s", hermes_slug, exc)
        # Fallback: check external credential files directly.
        # The credential pool gates anthropic behind
        # is_provider_explicitly_configured() to prevent auxiliary tasks
        # from silently consuming Claude Code tokens (PR #4210).
        # But the /model picker is discovery-oriented — we WANT to show
        # providers the user can switch to, even if they aren't currently
        # configured.
        if not has_creds and hermes_slug == "anthropic":
            try:
                from agent.anthropic_adapter import (
                    read_claude_code_credentials,
                    read_hermes_oauth_credentials,
                )
                hermes_creds = read_hermes_oauth_credentials()
                cc_creds = read_claude_code_credentials()
                if (hermes_creds and hermes_creds.get("accessToken")) or \
                   (cc_creds and cc_creds.get("accessToken")):
                    has_creds = True
            except Exception as exc:
                logger.debug("Anthropic external creds check failed: %s", exc)
        if not has_creds:
            continue

        if hermes_slug in {"openai-codex", "copilot", "copilot-acp"}:
            # Use live OAuth-backed discovery so the gateway /model picker
            # matches what the user's authenticated Codex/Copilot backend
            # actually serves — including ChatGPT-Pro-only Codex slugs
            # (e.g. gpt-5.3-codex-spark) that aren't in the static curated
            # catalog. ``cached_provider_model_ids()`` falls back to the
            # curated list when the live endpoint is unreachable, so this
            # is safe for unauthenticated and offline cases too.
            model_ids = cached_provider_model_ids(hermes_slug)
        # For aws_sdk providers (bedrock), use live discovery so the list
        # reflects the active region (eu.*, ap.*) not the static us.* list.
        elif overlay.auth_type == "aws_sdk":
            try:
                _ids = cached_provider_model_ids(hermes_slug)
                model_ids = _ids if _ids else (curated.get(hermes_slug, []) or curated.get(pid, []))
            except Exception:
                model_ids = curated.get(hermes_slug, []) or curated.get(pid, [])
        elif hermes_slug == "nous":
            # Nous serves a large live /v1/models catalog (vendor-prefixed
            # models from many providers, returned alphabetically). The
            # `hermes model` picker deliberately shows ONLY the curated agentic
            # list — augmented with the Portal's free/paid recommendations so
            # newly-launched models surface without a CLI release — in curated
            # order. Mirror that exactly (see _model_flow_nous in main.py) so
            # the GUI picker matches the CLI. Was: falling through to
            # cached_provider_model_ids, which dumped the full alphabetical
            # catalog; then: curated-only, which dropped the 4 Portal
            # recommendations (e.g. stepfun/step-3.7-flash:free).
            model_ids = curated.get("nous", [])
            try:
                from hermes_cli.models import (
                    get_pricing_for_provider as _nous_pricing,
                    check_nous_free_tier as _nous_free,
                    union_with_portal_free_recommendations as _union_free,
                    union_with_portal_paid_recommendations as _union_paid,
                )
                from hermes_cli.auth import get_provider_auth_state as _nous_state

                _pricing = _nous_pricing("nous") or {}
                _portal = ""
                try:
                    _st = _nous_state("nous") or {}
                    _portal = _st.get("portal_base_url", "") or ""
                except Exception:
                    _portal = ""
                if _nous_free(force_fresh=True):
                    model_ids, _ = _union_free(model_ids, _pricing, _portal)
                else:
                    model_ids, _ = _union_paid(model_ids, _pricing, _portal)
            except Exception:
                # Portal recommendation fetch failed — fall back to the
                # curated list alone (still correct, just may lag newly
                # launched models, exactly like an offline CLI run).
                pass
        else:
            # Unified pathway — see Section 1 rationale. Fall back to the
            # curated dict (with models.dev merge for preferred providers)
            # when the live fetcher comes up empty.
            model_ids = cached_provider_model_ids(hermes_slug)
            if not model_ids:
                model_ids = curated.get(hermes_slug, []) or curated.get(pid, [])
                if hermes_slug in _MODELS_DEV_PREFERRED:
                    model_ids = _merge_with_models_dev(hermes_slug, model_ids)
        total = len(model_ids)
        top = model_ids[:max_models]

        results.append({
            "slug": hermes_slug,
            "name": get_label(hermes_slug),
            "is_current": hermes_slug == current_provider or pid == current_provider,
            "is_user_defined": False,
            "models": top,
            "total_models": total,
            "source": "hermes",
        })
        seen_slugs.add(pid.lower())
        seen_slugs.add(hermes_slug.lower())
        _record_builtin_endpoint(hermes_slug)

    # --- 2b. Cross-check canonical provider list ---
    # Catches providers that are in CANONICAL_PROVIDERS but weren't found
    # in PROVIDER_TO_MODELS_DEV or HERMES_OVERLAYS (keeps /model in sync
    # with `hermes model`).
    try:
        from hermes_cli.models import CANONICAL_PROVIDERS as _canon_provs
    except ImportError:
        _canon_provs = []

    for _cp in _canon_provs:
        if _cp.slug.lower() in seen_slugs:
            continue

        # Check credentials via PROVIDER_REGISTRY (auth.py)
        _cp_config = _auth_registry.get(_cp.slug)
        _cp_has_creds = False
        if _cp_config and _cp_config.api_key_env_vars:
            _cp_has_creds = any(os.environ.get(ev) for ev in _cp_config.api_key_env_vars)
        # Also check auth store and credential pool
        if not _cp_has_creds:
            try:
                from hermes_cli.auth import _load_auth_store
                _cp_store = _load_auth_store()
                _cp_providers_store = _cp_store.get("providers", {})
                if _cp_store and _cp.slug in _cp_providers_store:
                    _cp_has_creds = True
            except Exception:
                pass
        if not _cp_has_creds:
            try:
                from agent.credential_pool import load_pool
                _cp_pool = load_pool(_cp.slug)
                if _cp_pool.has_credentials():
                    _cp_has_creds = True
            except Exception:
                pass

        # Special case: aws_sdk auth (bedrock) — no API key env vars,
        # credentials come from the boto3 credential chain (env vars,
        # ~/.aws/credentials, instance roles, etc.)
        if not _cp_has_creds and _cp_config and getattr(_cp_config, "auth_type", "") == "aws_sdk":
            _cp_has_creds = _has_aws_sdk_creds_for_listing(_cp.slug)

        if not _cp_has_creds:
            continue

        # For bedrock, use live discovery so the list reflects the active
        # region (eu.*, us.*, ap.*) instead of the hardcoded us.* static list.
        if _cp_config and getattr(_cp_config, "auth_type", "") == "aws_sdk":
            try:
                _ids = cached_provider_model_ids(_cp.slug)
                _cp_model_ids = _ids if _ids else curated.get(_cp.slug, [])
            except Exception:
                _cp_model_ids = curated.get(_cp.slug, [])
        else:
            # Unified pathway — same as sections 1 and 2.
            _cp_model_ids = cached_provider_model_ids(_cp.slug)
            if not _cp_model_ids:
                _cp_model_ids = curated.get(_cp.slug, [])
        _cp_total = len(_cp_model_ids)
        _cp_top = _cp_model_ids[:max_models]

        results.append({
            "slug": _cp.slug,
            "name": _cp.label,
            "is_current": _cp.slug == current_provider,
            "is_user_defined": False,
            "models": _cp_top,
            "total_models": _cp_total,
            "source": "canonical",
        })
        seen_slugs.add(_cp.slug.lower())
        _record_builtin_endpoint(_cp.slug)

    # --- 3. User-defined endpoints from config ---
    # Track (name, base_url) of what section 3 emits so section 4 can skip
    # any overlapping ``custom_providers:`` entries.  Callers typically pass
    # both (gateway/CLI invoke ``get_compatible_custom_providers()`` which
    # merges ``providers:`` into the list) — without this, the same endpoint
    # produces two picker rows: one bare-slug ("openrouter") from section 3
    # and one "custom:openrouter" from section 4, both labelled identically.
    _section3_emitted_pairs: set = set()
    if user_providers and isinstance(user_providers, dict):
        for ep_name, ep_cfg in user_providers.items():
            if not isinstance(ep_cfg, dict):
                continue
            # Skip if this slug was already emitted (e.g. canonical provider
            # with the same name) or will be picked up by section 4.
            if ep_name.lower() in seen_slugs:
                continue
            display_name = ep_cfg.get("name", "") or ep_name
            # ``base_url`` is Hermes's canonical write key (matches
            # custom_providers and _save_custom_provider); ``api`` / ``url``
            # remain as fallbacks for hand-edited / legacy configs.
            api_url = (
                ep_cfg.get("base_url", "")
                or ep_cfg.get("api", "")
                or ep_cfg.get("url", "")
                or ""
            )
            # ``default_model`` is the legacy key; ``model`` matches what
            # custom_providers entries use, so accept either.
            default_model = ep_cfg.get("default_model", "") or ep_cfg.get("model", "")

            # Build models list from both default_model and full models array
            models_list = []
            if default_model:
                models_list.append(default_model)
            # Also include the full models list from config.
            # Hermes writes ``models:`` as a dict keyed by model id
            # (see hermes_cli/main.py::_save_custom_provider); older
            # configs or hand-edited files may still use a list.
            cfg_models = ep_cfg.get("models", [])
            if isinstance(cfg_models, dict):
                for m in cfg_models:
                    if m and m not in models_list:
                        models_list.append(m)
            elif isinstance(cfg_models, list):
                for m in cfg_models:
                    if m and m not in models_list:
                        models_list.append(m)

            # Official OpenAI API rows in providers: often have base_url but no
            # explicit models: dict — avoid a misleading zero count in /model.
            if not models_list:
                url_lower = str(api_url).strip().lower()
                if "api.openai.com" in url_lower:
                    fb = curated.get("openai") or []
                    if fb:
                        models_list = list(fb)

            # Prefer the endpoint's live /models list when credentials are
            # available, unless the provider explicitly opts out via
            # discover_models: false (e.g. dedicated endpoints that expose
            # the entire aggregator catalog via /models).
            api_key = str(ep_cfg.get("api_key", "") or "").strip()
            if not api_key:
                key_env = str(ep_cfg.get("key_env", "") or "").strip()
                api_key = os.environ.get(key_env, "").strip() if key_env else ""
            discover = ep_cfg.get("discover_models", True)
            if isinstance(discover, str):
                discover = discover.lower() not in {"false", "no", "0"}
            if api_url and api_key and discover:
                try:
                    from hermes_cli.models import fetch_api_models
                    live_models = fetch_api_models(api_key, api_url)
                    if live_models:
                        models_list = live_models
                except Exception:
                    pass

            results.append({
                "slug": ep_name,
                "name": display_name,
                "is_current": ep_name == current_provider,
                "is_user_defined": True,
                "models": models_list,
                "total_models": len(models_list) if models_list else 0,
                "source": "user-config",
                "api_url": api_url,
            })
            seen_slugs.add(ep_name.lower())
            seen_slugs.add(custom_provider_slug(display_name).lower())
            _pair = (
                str(display_name).strip().lower(),
                str(api_url).strip().rstrip("/").lower(),
            )
            if _pair[0] and _pair[1]:
                _section3_emitted_pairs.add(_pair)

    # --- 4. Saved custom providers from config ---
    # Each ``custom_providers`` entry represents one model under a named
    # provider. Entries sharing the same endpoint, credential identity, and
    # wire protocol are grouped into a single picker row, so e.g. four Ollama
    # entries pointing at ``http://localhost:11434/v1`` with per-model display
    # names ("Ollama — GLM 5.1", "Ollama — Qwen3-coder", ...) appear as one
    # "Ollama" row with four models inside instead of four near-duplicates
    # that differ only by suffix. Same-host entries with different ``key_env``
    # or ``api_mode`` remain distinct providers.
    if custom_providers and isinstance(custom_providers, list):
        from collections import OrderedDict

        # Key by endpoint + credential identity + wire protocol instead of
        # slug: names frequently differ per model ("Ollama — X") while the
        # endpoint stays the same.  Keep same-host providers with distinct
        # env-backed credentials or API protocols separate so picker selection
        # cannot route through the wrong credential/mode pair.
        groups: "OrderedDict[tuple, dict]" = OrderedDict()
        for entry in custom_providers:
            if not isinstance(entry, dict):
                continue

            raw_name = (entry.get("name") or "").strip()
            api_url = (
                entry.get("base_url", "")
                or entry.get("url", "")
                or entry.get("api", "")
                or ""
            ).strip().rstrip("/")
            if not raw_name or not api_url:
                continue
            inline_api_key = (entry.get("api_key") or "").strip()
            key_env = (entry.get("key_env") or "").strip()
            api_key = inline_api_key or (
                os.environ.get(key_env, "").strip() if key_env else ""
            )
            api_mode = str(
                entry.get("api_mode")
                or entry.get("transport")
                or ""
            ).strip().lower()
            credential_identity = (
                inline_api_key
                if inline_api_key
                else (f"env:{key_env}" if key_env else "")
            )

            # Read discover_models from the entry (same semantics as
            # section 3: true by default, set false to keep the explicit
            # ``models:`` list instead of replacing it with live /models).
            discover = entry.get("discover_models", True)
            if isinstance(discover, str):
                discover = discover.lower() not in {"false", "no", "0"}

            group_key = (api_url, credential_identity, api_mode)
            if group_key not in groups:
                # Strip per-model suffix so "Ollama — GLM 5.1" becomes
                # "Ollama" for the grouped row. Em dash is the convention
                # Hermes's own writer uses; a hyphen variant is accepted
                # for hand-edited configs.
                display_name = raw_name
                for sep in ("—", " - "):
                    if sep in display_name:
                        display_name = display_name.split(sep)[0].strip()
                        break
                if not display_name:
                    display_name = raw_name
                slug = custom_provider_slug(display_name)
                groups[group_key] = {
                    "slug": slug,
                    "name": display_name,
                    "api_url": api_url,
                    "api_key": api_key,
                    "models": [],
                    "discover_models": discover,
                }
            else:
                if api_key and not groups[group_key].get("api_key"):
                    groups[group_key]["api_key"] = api_key
                # If any entry in this group opts out of discovery,
                # honour that for the whole grouped row.
                if not discover:
                    groups[group_key]["discover_models"] = False

            # The singular ``model:`` field only holds the currently
            # active model. Hermes's own writer (main.py::_save_custom_provider)
            # stores every configured model as a dict under ``models:``;
            # downstream readers (agent/models_dev.py, gateway/run.py,
            # run_agent.py, hermes_cli/config.py) already consume that dict.
            default_model = (entry.get("model") or "").strip()
            if default_model and default_model not in groups[group_key]["models"]:
                groups[group_key]["models"].append(default_model)

            cfg_models = entry.get("models", {})
            if isinstance(cfg_models, dict):
                for m in cfg_models:
                    if m and m not in groups[group_key]["models"]:
                        groups[group_key]["models"].append(m)
            elif isinstance(cfg_models, list):
                for m in cfg_models:
                    if m and m not in groups[group_key]["models"]:
                        groups[group_key]["models"].append(m)

        _section4_emitted_slugs: set = set()
        _current_base_url_norm = str(current_base_url or "").strip().rstrip("/").lower()
        _current_base_url_group_count = sum(
            1
            for _grp in groups.values()
            if _current_base_url_norm
            and str(_grp["api_url"]).strip().rstrip("/").lower() == _current_base_url_norm
        )
        for grp in groups.values():
            api_url = grp["api_url"]
            api_key = grp.get("api_key", "")
            slug = grp["slug"]
            # If the slug is already claimed by a built-in / overlay /
            # user-provider row (sections 1-3), skip this custom group
            # to avoid shadowing a real provider.
            if slug.lower() in seen_slugs and slug.lower() not in _section4_emitted_slugs:
                continue
            # If a prior section-4 group already used this slug (two custom
            # endpoints with the same cleaned name — e.g. two OpenAI-
            # compatible gateways named identically with different keys),
            # append a counter so both rows stay visible in the picker.
            if slug.lower() in _section4_emitted_slugs:
                base_slug = slug
                n = 2
                while f"{base_slug}-{n}".lower() in seen_slugs:
                    n += 1
                slug = f"{base_slug}-{n}"
                grp["slug"] = slug
            # Skip if section 3 already emitted this endpoint under its
            # ``providers:`` dict key — matches on (display_name, base_url).
            # Prevents two picker rows labelled identically when callers
            # pass both ``user_providers`` and a compatibility-merged
            # ``custom_providers`` list.
            _pair_key = (
                str(grp["name"]).strip().lower(),
                str(grp["api_url"]).strip().rstrip("/").lower(),
            )
            if _pair_key[0] and _pair_key[1] and _pair_key in _section3_emitted_pairs:
                continue
            # Skip if a built-in row (sections 1/2/2b) already represents this
            # endpoint. Fixes #16970: a user-defined "my-dashscope" pointing at
            # https://coding-intl.dashscope.aliyuncs.com/v1 duplicates the
            # built-in alibaba-coding-plan row whenever DASHSCOPE_API_KEY is
            # set. The built-in row carries the curated model list, correct
            # auth wiring, and canonical slug — keep it and hide the shadow.
            _grp_url_norm = _pair_key[1]
            if _grp_url_norm and _grp_url_norm in _builtin_endpoints:
                continue
            # Live model discovery from custom provider endpoints (matches
            # Section 3 behavior for user ``providers:`` entries).
            # Also probes when no api_key is set (e.g. local llama.cpp /
            # Ollama servers) — the /models endpoint often works without
            # auth.  The CLI's _model_flow_named_custom always probes, so
            # the Telegram/Discord picker should do the same for parity.
            # Live-discovery policy:
            # - With an api_key, the user has explicitly opted into the
            #   endpoint and live /models is the source of truth — replace
            #   the (possibly partial) ``models:`` subset configured for
            #   context-length overrides with the full live catalog.
            #   This is the Bifrost / aggregator-gateway case.
            # - Without an api_key but with an explicit ``models:`` list
            #   (or top-level ``model:``), the user is narrowing a public
            #   endpoint to a specific subset (e.g. ollama.com /v1/models
            #   returns 35 models but the user only wants 4). Preserve the
            #   explicit list and skip live discovery.
            # - Without an api_key AND no explicit models, fall through to
            #   live discovery so bare-endpoint custom providers (local
            #   llama.cpp / Ollama servers) still appear populated.
            # - When discover_models: false is set, skip live discovery and
            #   keep the explicit ``models:`` list regardless of whether an
            #   api_key is present. This supports endpoints that expose a
            #   full aggregator catalog via /models but only serve a subset
            #   (parity with section 3's user ``providers:`` behaviour).
            should_probe = (
                bool(api_url)
                and (bool(api_key) or not grp["models"])
                and grp.get("discover_models", True)
            )
            if should_probe:
                try:
                    from hermes_cli.models import fetch_api_models

                    live_models = fetch_api_models(api_key, api_url)
                    if live_models:
                        grp["models"] = live_models
                        grp["total_models"] = len(live_models)
                except Exception:
                    pass
            results.append({
                "slug": slug,
                "name": grp["name"],
                "is_current": slug == current_provider or (
                    current_provider == "custom"
                    and bool(_current_base_url_norm)
                    and _grp_url_norm == _current_base_url_norm
                    and _current_base_url_group_count == 1
                ),
                "is_user_defined": True,
                "models": grp["models"],
                "total_models": len(grp["models"]),
                "source": "user-config",
                "api_url": grp["api_url"],
            })
            seen_slugs.add(slug.lower())
            _section4_emitted_slugs.add(slug.lower())

    # Sort: current provider first, then by model count descending
    results.sort(key=lambda r: (not r["is_current"], -r["total_models"]))

    return results


def list_picker_providers(
    current_provider: str = "",
    current_base_url: str = "",
    user_providers: dict = None,
    custom_providers: list | None = None,
    max_models: int = 8,
    current_model: str = "",
) -> List[dict]:
    """Interactive-picker variant of :func:`list_authenticated_providers`.

    Post-processes the base list so the ``/model`` picker (Telegram/Discord
    inline keyboards) only surfaces models that are actually callable in the
    current install:

    - OpenRouter's model list is replaced with the output of
      :func:`hermes_cli.models.fetch_openrouter_models`, which filters the
      curated ``OPENROUTER_MODELS`` snapshot against the live OpenRouter
      catalog.  IDs the live catalog no longer carries drop out, so the
      picker never offers a model the user can't call.
    - Provider rows whose model list ends up empty are dropped, except
      custom endpoints (``is_user_defined=True`` with an ``api_url``) where
      the user may supply their own model set through config.

    All other providers and metadata fields are passed through unchanged.
    The typed ``/model <name>`` path is unaffected -- only the interactive
    picker payload is narrowed.
    """
    from hermes_cli.models import fetch_openrouter_models

    providers = list_authenticated_providers(
        current_provider=current_provider,
        current_base_url=current_base_url,
        user_providers=user_providers,
        custom_providers=custom_providers,
        max_models=max_models,
        current_model=current_model,
    )

    filtered: List[dict] = []
    for p in providers:
        slug = str(p.get("slug", "")).lower()
        if slug == "openrouter":
            try:
                live = fetch_openrouter_models()
                live_ids = [mid for mid, _ in live]
            except Exception:
                live_ids = list(p.get("models", []))
            p = dict(p)
            p["models"] = live_ids[:max_models]
            p["total_models"] = len(live_ids)

        has_models = bool(p.get("models"))
        is_custom_endpoint = bool(p.get("is_user_defined")) and bool(p.get("api_url"))
        if not has_models and not is_custom_endpoint:
            continue
        filtered.append(p)

    return filtered
