"""
Admin router — plugin management and user CRUD.
All endpoints require admin role.
"""

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.dependencies import get_db, require_admin
from app.models.plugin import Plugin
from app.models.user import User
from app.plugins.loader import BUILTIN_ACTIONS
from app.plugins.registry import action_registry
from app.schemas.admin import PluginRead, PluginUpdate, UserCreate, UserRead, UserUpdate
from app.services.auth import hash_password

router = APIRouter(prefix="/api/v1/admin", tags=["admin"])


# ── Plugins ────────────────────────────────────────────────────────────────────

@router.get("/plugins", response_model=list[PluginRead])
async def list_plugins(
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_admin),
):
    result = await db.execute(select(Plugin).order_by(Plugin.name))
    plugins = result.scalars().all()

    out = []
    for p in plugins:
        action = BUILTIN_ACTIONS.get(p.name)
        out.append(
            PluginRead(
                name=p.name,
                display_name=p.display_name,
                description=p.description,
                enabled=p.enabled,
                registered_at=p.registered_at,
                compatible_categories=action.compatible_categories if action else [],
            )
        )
    return out


@router.patch("/plugins/{name}", response_model=PluginRead)
async def update_plugin(
    name: str,
    body: PluginUpdate,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_admin),
):
    plugin = await db.get(Plugin, name)
    if plugin is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Plugin not found")

    plugin.enabled = body.enabled

    # Hot-reload the registry immediately
    if body.enabled:
        action = BUILTIN_ACTIONS.get(name)
        if action:
            action_registry.register(action)
    else:
        action_registry.unregister(name)

    await db.flush()
    action = BUILTIN_ACTIONS.get(name)
    return PluginRead(
        name=plugin.name,
        display_name=plugin.display_name,
        description=plugin.description,
        enabled=plugin.enabled,
        registered_at=plugin.registered_at,
        compatible_categories=action.compatible_categories if action else [],
    )


# ── Users ──────────────────────────────────────────────────────────────────────

@router.get("/users", response_model=list[UserRead])
async def list_users(
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_admin),
):
    result = await db.execute(select(User).order_by(User.username))
    return result.scalars().all()


@router.post("/users", response_model=UserRead, status_code=status.HTTP_201_CREATED)
async def create_user(
    body: UserCreate,
    db: AsyncSession = Depends(get_db),
    _: User = Depends(require_admin),
):
    # Check username uniqueness
    existing = await db.execute(select(User).where(User.username == body.username))
    if existing.scalar_one_or_none() is not None:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail=f"Username '{body.username}' is already taken",
        )

    user = User(
        username=body.username,
        email=body.email,
        full_name=body.full_name,
        password_hash=hash_password(body.password),
        role=body.role,
        is_active=True,
    )
    db.add(user)
    await db.flush()
    await db.refresh(user)
    return user


@router.patch("/users/{user_id}", response_model=UserRead)
async def update_user(
    user_id: int,
    body: UserUpdate,
    db: AsyncSession = Depends(get_db),
    current_admin: User = Depends(require_admin),
):
    user = await db.get(User, user_id)
    if user is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")

    if body.email is not None:
        user.email = body.email
    if body.full_name is not None:
        user.full_name = body.full_name
    if body.role is not None:
        user.role = body.role
    if body.is_active is not None:
        user.is_active = body.is_active
    if body.password:
        user.password_hash = hash_password(body.password)

    await db.flush()
    await db.refresh(user)
    return user


@router.delete("/users/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_user(
    user_id: int,
    db: AsyncSession = Depends(get_db),
    current_admin: User = Depends(require_admin),
):
    if user_id == current_admin.id:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Cannot delete your own account",
        )
    user = await db.get(User, user_id)
    if user is None:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
    await db.delete(user)