"""Controller decorators for console app resources.

`get_app_model` still supports legacy handlers backed by Flask-SQLAlchemy's
scoped session. Trial app handlers compose `get_app_model_with_trial` under
`controllers.common.session.with_session` and always reuse that request session.
"""

from collections.abc import Callable
from functools import wraps
from typing import cast, overload

from sqlalchemy import select
from sqlalchemy.orm import Session

from controllers.common.session import with_session
from controllers.console.app.error import AppNotFoundError
from extensions.ext_database import db
from libs.login import current_account_with_tenant
from models import App, AppMode, TrialApp
from services.recommended_app_service import RecommendedAppService

__all__ = ["get_app_model", "get_app_model_with_trial", "with_session"]


def _load_app_model(session: Session, app_id: str) -> App | None:
    """Load the tenant-scoped app row with the request session owned by `with_session`."""
    _, current_tenant_id = current_account_with_tenant()
    app_model = session.scalar(
        select(App).where(App.id == app_id, App.tenant_id == current_tenant_id, App.status == "normal").limit(1)
    )
    return app_model


def _load_app_model_from_scoped_session(app_id: str) -> App | None:
    """Load the app row for legacy handlers that have not adopted request session injection yet."""
    _, current_tenant_id = current_account_with_tenant()
    app_model = db.session.scalar(
        select(App).where(App.id == app_id, App.tenant_id == current_tenant_id, App.status == "normal").limit(1)
    )
    return app_model


def _load_app_model_with_trial(session: Session, app_id: str) -> App | None:
    """Load a normal app through its trial registration without applying current-tenant scope."""
    app_model = session.scalar(
        select(App).join(TrialApp, TrialApp.app_id == App.id).where(App.id == app_id, App.status == "normal").limit(1)
    )
    return app_model


def _get_injected_session(args: tuple[object, ...]) -> Session | None:
    """Return the request session inserted by `with_session`, if this handler has been migrated."""
    if len(args) < 2:
        return None

    candidate = args[1]
    if isinstance(candidate, Session):
        return candidate

    if hasattr(candidate, "scalar") and hasattr(candidate, "commit") and hasattr(candidate, "rollback"):
        return cast(Session, candidate)

    return None


@overload
def get_app_model[**P, R](
    view: Callable[P, R],
    *,
    mode: AppMode | list[AppMode] | None = None,
) -> Callable[P, R]: ...


@overload
def get_app_model[**P, R](
    view: None = None,
    *,
    mode: AppMode | list[AppMode] | None = None,
) -> Callable[[Callable[P, R]], Callable[P, R]]: ...


def get_app_model[**P, R](
    view: Callable[P, R] | None = None,
    *,
    mode: AppMode | list[AppMode] | None = None,
) -> Callable[P, R] | Callable[[Callable[P, R]], Callable[P, R]]:
    """Inject the App model for handlers that receive an `app_id` path parameter.

    New handlers may compose `@with_session` above this decorator so the app row
    is loaded through the same request-scoped session used by the controller.
    Existing handlers continue to work through `db.session` until migrated.
    """

    def decorator(view_func: Callable[P, R]) -> Callable[P, R]:
        @wraps(view_func)
        def decorated_view(*args: P.args, **kwargs: P.kwargs) -> R:
            if not kwargs.get("app_id"):
                raise ValueError("missing app_id in path parameters")

            app_id = kwargs.get("app_id")
            app_id = str(app_id)

            del kwargs["app_id"]

            session = _get_injected_session(args)
            if session is None:
                app_model = _load_app_model_from_scoped_session(app_id)
            else:
                app_model = _load_app_model(session, app_id)

            if not app_model:
                raise AppNotFoundError()

            app_mode = AppMode.value_of(app_model.mode)

            if mode is not None:
                if isinstance(mode, list):
                    modes = mode
                else:
                    modes = [mode]

                if app_mode not in modes:
                    mode_values = {m.value for m in modes}
                    raise AppNotFoundError(f"App mode is not in the supported list: {mode_values}")

            kwargs["app_model"] = app_model

            return view_func(*args, **kwargs)

        return decorated_view

    if view is None:
        return decorator
    else:
        return decorator(view)


@overload
def get_app_model_with_trial[**P, R](
    view: Callable[P, R],
    *,
    mode: AppMode | list[AppMode] | None = None,
) -> Callable[P, R]: ...


@overload
def get_app_model_with_trial[**P, R](
    view: None = None,
    *,
    mode: AppMode | list[AppMode] | None = None,
) -> Callable[[Callable[P, R]], Callable[P, R]]: ...


def get_app_model_with_trial[**P, R](
    view: Callable[P, R] | None = None,
    *,
    mode: AppMode | list[AppMode] | None = None,
) -> Callable[P, R] | Callable[[Callable[P, R]], Callable[P, R]]:
    """Inject a trial-registered or recommended App using the Session supplied by `with_session`."""

    def decorator(view_func: Callable[P, R]) -> Callable[P, R]:
        @wraps(view_func)
        def decorated_view(*args: P.args, **kwargs: P.kwargs) -> R:
            if not kwargs.get("app_id"):
                raise ValueError("missing app_id in path parameters")

            app_id = kwargs.get("app_id")
            app_id = str(app_id)

            del kwargs["app_id"]

            session = _get_injected_session(args)
            if session is None:
                raise RuntimeError("get_app_model_with_trial requires @with_session")
            app_model = _load_app_model_with_trial(session, app_id)
            if app_model is None:
                app_model = RecommendedAppService.get_app(app_id, session=session)

            if not app_model:
                raise AppNotFoundError()

            app_mode = AppMode.value_of(app_model.mode)

            if mode is not None:
                if isinstance(mode, list):
                    modes = mode
                else:
                    modes = [mode]

                if app_mode not in modes:
                    mode_values = {m.value for m in modes}
                    raise AppNotFoundError(f"App mode is not in the supported list: {mode_values}")

            kwargs["app_model"] = app_model

            return view_func(*args, **kwargs)

        return decorated_view

    if view is None:
        return decorator
    else:
        return decorator(view)