"""Server-side model grant resolution and redacted model views.

Grants carry LLM assignments only (grant v2): embedding and search always
resolve from the deployment's active profiles, so per-user grants for them
were never enforced and are not stored.
"""

from __future__ import annotations

from typing import Any

from deeptutor.services.config.model_catalog import ModelCatalogService
from deeptutor.services.model_selection import list_llm_options

from .context import get_current_user
from .grants import load_grant
from .paths import get_admin_path_service


def admin_catalog_service() -> ModelCatalogService:
    return ModelCatalogService(path=get_admin_path_service().get_settings_file("model_catalog"))


def admin_catalog() -> dict[str, Any]:
    return admin_catalog_service().load()


def _profile_by_id(catalog: dict[str, Any], service: str, profile_id: str) -> dict[str, Any] | None:
    for profile in catalog.get("services", {}).get(service, {}).get("profiles", []) or []:
        if str(profile.get("id") or "") == profile_id:
            return profile
    return None


def _model_by_id(profile: dict[str, Any], model_id: str) -> dict[str, Any] | None:
    for model in profile.get("models", []) or []:
        if str(model.get("id") or "") == model_id:
            return model
    return None


def redacted_model_access(user_id: str | None = None) -> dict[str, list[dict[str, Any]]]:
    user = get_current_user()
    if user_id is None:
        user_id = user.id
    grant = load_grant(user_id)
    catalog = admin_catalog()
    result: dict[str, list[dict[str, Any]]] = {"llm": []}
    for item in grant.get("models", {}).get("llm", []) or []:
        profile_id = str(item.get("profile_id") or item.get("id") or "")
        profile = _profile_by_id(catalog, "llm", profile_id)
        if not profile:
            result["llm"].append(
                {
                    "profile_id": profile_id,
                    "name": item.get("name") or profile_id or "Unavailable profile",
                    "source": "admin",
                    "available": False,
                }
            )
            continue
        for model_id in item.get("model_ids") or []:
            model = _model_by_id(profile, str(model_id))
            result["llm"].append(
                {
                    "profile_id": profile_id,
                    "model_id": str(model_id),
                    "name": (model or {}).get("name") or str(model_id),
                    "model": (model or {}).get("model") or "",
                    "source": "admin",
                    "available": model is not None,
                }
            )
    return result


def allowed_llm_options() -> dict[str, Any]:
    user = get_current_user()
    if user.is_admin:
        return list_llm_options(admin_catalog())
    options = [
        {
            "profile_id": item.get("profile_id"),
            "model_id": item.get("model_id"),
            "profile_name": item.get("name") or item.get("profile_id") or "LLM",
            "model_name": item.get("name") or item.get("model") or item.get("model_id"),
            "label": item.get("name") or item.get("model") or item.get("model_id"),
            "model": item.get("model") or "",
            "provider": "",
            "source": "admin",
            "is_active_default": False,
        }
        for item in redacted_model_access(user.id).get("llm", [])
        if item.get("available")
    ]
    return {"active": None, "options": options}


def has_capability_access(capability: str, user_id: str | None = None) -> bool:
    """Whether the user has at least one usable model for ``capability``.

    Admins are never gated — they manage the catalog directly. For ordinary
    users this mirrors exactly what ``redacted_model_access`` exposes to the
    frontend, so the server-side gate and the UI lock always agree.
    """
    user = get_current_user()
    if user.is_admin:
        return True
    if user_id is None:
        user_id = user.id
    items = redacted_model_access(user_id).get(capability, []) or []
    return any(item.get("available") for item in items)


def apply_allowed_llm_selection(selection: dict[str, Any] | None) -> dict[str, Any] | None:
    """Allow only admin-granted LLM profile/model selections for ordinary users."""
    user = get_current_user()
    if user.is_admin or not selection:
        return selection
    profile_id = str(selection.get("profile_id") or "")
    model_id = str(selection.get("model_id") or "")
    for item in redacted_model_access(user.id).get("llm", []):
        if item.get("profile_id") == profile_id and item.get("model_id") == model_id:
            return selection
    raise PermissionError("This model is not assigned to your account.")