import math
from app.core.exceptions import ConflictError, NotFoundError
from app.core.security import get_password_hash
from app.repositories.user import UserRepository
from app.schemas.user import UserCreate, UserListResponse, UserResponse, UserUpdate


class UserService:
    def __init__(self, repo: UserRepository):
        self.repo = repo

    async def list_users(self, page: int, size: int) -> UserListResponse:
        users, total = await self.repo.list(
            offset=(page - 1) * size,
            limit=size,
            order_by=None,
        )
        return UserListResponse(
            items=[UserResponse.model_validate(u) for u in users],
            total=total,
            page=page,
            size=size,
            pages=math.ceil(total / size) if total else 1,
        )

    async def create_user(self, data: UserCreate) -> UserResponse:
        if await self.repo.get_by_username(data.username):
            raise ConflictError("البيانات المدخلة غير صحيحة")

        if data.email and await self.repo.get_by_email(data.email):
            raise ConflictError("البيانات المدخلة غير صحيحة")

        user = await self.repo.create(
            username=data.username,
            email=data.email,
            password_hash=get_password_hash(data.password),
            role=data.role,
        )
        return UserResponse.model_validate(user)

    async def get_user(self, user_id: int) -> UserResponse:
        user = await self.repo.get(user_id)
        if not user:
            raise NotFoundError("User")
        return UserResponse.model_validate(user)

    async def update_user(self, user_id: int, data: UserUpdate) -> UserResponse:
        user = await self.repo.get(user_id)
        if not user:
            raise NotFoundError("User")

        updates = data.model_dump(exclude_unset=True)

        if "email" in updates and updates["email"] and updates["email"] != user.email:
            existing = await self.repo.get_by_email(updates["email"])
            if existing:
                raise ConflictError("البيانات المدخلة غير صحيحة")  # ✅ تم التعديل

        if "password" in updates:
            updates["password_hash"] = get_password_hash(updates.pop("password"))

        user = await self.repo.update(user, **updates)
        return UserResponse.model_validate(user)

    async def delete_user(self, user_id: int, current_admin_id: int) -> None:
        if user_id == current_admin_id:
            raise ConflictError("Cannot delete your own account")
        user = await self.repo.get(user_id)
        if not user:
            raise NotFoundError("User")
        await self.repo.delete(user)