from typing import Optional, List
from sqlalchemy.orm import Session
from fastapi import HTTPException, status

from app.models.user import User, Role, Dept, UserRole
from app.schemas.user import UserCreate, UserUpdate
from app.core.security import get_password_hash


def get_user_by_id(db: Session, user_id: int) -> Optional[User]:
    return db.query(User).filter(User.id == user_id).first()


def get_user_by_username(db: Session, username: str) -> Optional[User]:
    return db.query(User).filter(User.username == username).first()


def create_user(db: Session, obj_in: UserCreate) -> User:
    if get_user_by_username(db, obj_in.username):
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="用户名已存在")

    db_obj = User(
        username=obj_in.username,
        email=obj_in.email,
        hashed_password=get_password_hash(obj_in.password),
        real_name=obj_in.real_name,
        phone=obj_in.phone,
        dept_id=obj_in.dept_id,
        is_active=obj_in.is_active,
    )
    db.add(db_obj)
    db.commit()
    db.refresh(db_obj)

    if obj_in.role_ids:
        for rid in obj_in.role_ids:
            role = db.query(Role).filter(Role.id == rid).first()
            if role:
                db.add(UserRole(user_id=db_obj.id, role_id=rid))
        db.commit()
        db.refresh(db_obj)

    return db_obj


def update_user(db: Session, db_obj: User, obj_in: UserUpdate) -> User:
    update_data = obj_in.model_dump(exclude_unset=True)
    role_ids = update_data.pop("role_ids", None)

    for field, value in update_data.items():
        setattr(db_obj, field, value)

    if role_ids is not None:
        db.query(UserRole).filter(UserRole.user_id == db_obj.id).delete()
        for rid in role_ids:
            role = db.query(Role).filter(Role.id == rid).first()
            if role:
                db.add(UserRole(user_id=db_obj.id, role_id=rid))

    db.commit()
    db.refresh(db_obj)
    return db_obj


def delete_user(db: Session, user_id: int) -> None:
    user = get_user_by_id(db, user_id)
    if not user:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="用户不存在")
    if user.is_superuser:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="不能删除超级管理员")
    db.delete(user)
    db.commit()


def list_users(db: Session, keyword: Optional[str] = None, page: int = 1, page_size: int = 20):
    query = db.query(User)
    if keyword:
        query = query.filter(
            (User.username.contains(keyword))
            | (User.real_name.contains(keyword))
            | (User.email.contains(keyword))
        )
    total = query.count()
    items = query.offset((page - 1) * page_size).limit(page_size).all()
    return items, total


def create_initial_data(db: Session):
    # Create default roles
    default_roles = [
        {"name": "超级管理员", "code": "superadmin", "description": "系统超级管理员"},
        {"name": "管理员", "code": "admin", "description": "系统管理员"},
        {"name": "项目负责人", "code": "project_manager", "description": "分类分级项目负责人"},
        {"name": "打标员", "code": "labeler", "description": "数据打标人员"},
        {"name": "审核员", "code": "reviewer", "description": "结果审核人员"},
        {"name": "访客", "code": "guest", "description": "只读访客"},
    ]
    for r in default_roles:
        if not db.query(Role).filter(Role.code == r["code"]).first():
            db.add(Role(**r))

    # Create root dept
    if not db.query(Dept).filter(Dept.id == 1).first():
        db.add(Dept(id=1, name="根部门", parent_id=None, sort_order=0))

    db.commit()

    # Create superuser
    from app.core.config import settings
    if not get_user_by_username(db, settings.FIRST_SUPERUSER_USERNAME):
        superuser = User(
            username=settings.FIRST_SUPERUSER_USERNAME,
            email=settings.FIRST_SUPERUSER_EMAIL,
            hashed_password=get_password_hash(settings.FIRST_SUPERUSER_PASSWORD),
            real_name="超级管理员",
            is_active=True,
            is_superuser=True,
            dept_id=1,
        )
        db.add(superuser)
        db.commit()
        db.refresh(superuser)

        superadmin_role = db.query(Role).filter(Role.code == "superadmin").first()
        if superadmin_role:
            db.add(UserRole(user_id=superuser.id, role_id=superadmin_role.id))
            db.commit()