"""Users router: admin-only user management (list, create, update, deactivate)."""

import uuid

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

from app.database import get_db
from app.dependencies import get_pagination, require_role
from app.models.user import User
from app.schemas.user import (
    UserCreate,
    UserListResponse,
    UserResponse,
    UserUpdate,
)
from app.services.auth_service import (
    create_user as svc_create_user,
    deactivate_user as svc_deactivate_user,
    list_users as svc_list_users,
    update_user as svc_update_user,
)

router = APIRouter(prefix="/users", tags=["users"])


@router.get("/", response_model=UserListResponse, status_code=status.HTTP_200_OK)
async def list_users(
    db: AsyncSession = Depends(get_db),
    pagination: dict = Depends(get_pagination),
    admin: User = Depends(require_role(["admin"])),
):
    """List all users with pagination. Admin only."""
    users, total = await svc_list_users(
        db, page=pagination["page"], page_size=pagination["page_size"]
    )
    return UserListResponse(
        items=[UserResponse.model_validate(u) for u in users],
        total=total,
        page=pagination["page"],
        page_size=pagination["page_size"],
    )


@router.post("/", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
async def create_user(
    body: UserCreate,
    db: AsyncSession = Depends(get_db),
    admin: User = Depends(require_role(["admin"])),
):
    """Create a new user. Admin only."""
    try:
        user = await svc_create_user(
            db,
            email=body.email,
            password=body.password,
            full_name=body.full_name,
            role=body.role,
            language=body.language,
        )
    except ValueError as exc:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail={"error": {"code": "DUPLICATE_EMAIL", "message": str(exc)}},
        )
    return UserResponse.model_validate(user)


@router.put("/{user_id}", response_model=UserResponse, status_code=status.HTTP_200_OK)
async def update_user(
    user_id: uuid.UUID,
    body: UserUpdate,
    db: AsyncSession = Depends(get_db),
    admin: User = Depends(require_role(["admin"])),
):
    """Update a user's fields. Admin only."""
    updates = body.model_dump(exclude_unset=True)
    if not updates:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail={"error": {"code": "NO_FIELDS", "message": "No fields to update"}},
        )
    user = await svc_update_user(db, user_id, **updates)
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail={"error": {"code": "USER_NOT_FOUND", "message": "User not found"}},
        )
    return UserResponse.model_validate(user)


@router.delete(
    "/{user_id}", response_model=UserResponse, status_code=status.HTTP_200_OK
)
async def delete_user(
    user_id: uuid.UUID,
    db: AsyncSession = Depends(get_db),
    admin: User = Depends(require_role(["admin"])),
):
    """Deactivate a user (soft delete). Admin only."""
    user = await svc_deactivate_user(db, user_id)
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail={"error": {"code": "USER_NOT_FOUND", "message": "User not found"}},
        )
    return UserResponse.model_validate(user)