from datetime import datetime

from fastapi import APIRouter, Depends, HTTPException, Request, status
from fastapi.security import OAuth2PasswordRequestForm
from pydantic import BaseModel
from sqlalchemy.orm import Session

from server.db_manager import db_manager
from server.models.user_model import User
from server.utils.auth_middleware import get_admin_user, get_current_user, get_db
from server.utils.auth_utils import AuthUtils
from server.utils.common_utils import log_operation

# 创建路由器
auth = APIRouter(prefix="/auth", tags=["authentication"])


# 请求和响应模型
class Token(BaseModel):
    access_token: str
    token_type: str
    user_id: int
    username: str
    role: str


class UserCreate(BaseModel):
    username: str
    password: str
    role: str = "user"


class UserUpdate(BaseModel):
    username: str | None = None
    password: str | None = None
    role: str | None = None


class UserResponse(BaseModel):
    id: int
    username: str
    role: str
    created_at: str
    last_login: str | None = None


class InitializeAdmin(BaseModel):
    username: str
    password: str


# =============================================================================
# === 工具函数 ===
# =============================================================================


# 路由：登录获取令牌
# =============================================================================
# === 认证分组 ===
# =============================================================================


@auth.post("/token", response_model=Token)
async def login_for_access_token(form_data: OAuth2PasswordRequestForm = Depends(), db: Session = Depends(get_db)):
    # 查找用户
    user = db.query(User).filter(User.username == form_data.username).first()

    # 验证用户存在且密码正确
    if not user or not AuthUtils.verify_password(user.password_hash, form_data.password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="用户名或密码错误",
            headers={"WWW-Authenticate": "Bearer"},
        )

    # 更新最后登录时间
    user.last_login = datetime.now()
    db.commit()

    # 生成访问令牌
    token_data = {"sub": str(user.id)}
    access_token = AuthUtils.create_access_token(token_data)

    # 记录登录操作
    log_operation(db, user.id, "登录")

    return {
        "access_token": access_token,
        "token_type": "bearer",
        "user_id": user.id,
        "username": user.username,
        "role": user.role,
    }


# 路由：校验是否需要初始化管理员
@auth.get("/check-first-run")
async def check_first_run():
    is_first_run = db_manager.check_first_run()
    return {"first_run": is_first_run}


# 路由：初始化管理员账户
@auth.post("/initialize", response_model=Token)
async def initialize_admin(admin_data: InitializeAdmin, db: Session = Depends(get_db)):
    # 检查是否是首次运行
    if not db_manager.check_first_run():
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="系统已经初始化，无法再次创建初始管理员",
        )

    # 创建管理员账户
    hashed_password = AuthUtils.hash_password(admin_data.password)

    new_admin = User(
        username=admin_data.username, password_hash=hashed_password, role="superadmin", last_login=datetime.now()
    )

    db.add(new_admin)
    db.commit()
    db.refresh(new_admin)

    # 生成访问令牌
    token_data = {"sub": str(new_admin.id)}
    access_token = AuthUtils.create_access_token(token_data)

    # 记录操作
    log_operation(db, new_admin.id, "系统初始化", "创建超级管理员账户")

    return {
        "access_token": access_token,
        "token_type": "bearer",
        "user_id": new_admin.id,
        "username": new_admin.username,
        "role": new_admin.role,
    }


# 路由：获取当前用户信息
# =============================================================================
# === 用户信息分组 ===
# =============================================================================


@auth.get("/me", response_model=UserResponse)
async def read_users_me(current_user: User = Depends(get_current_user)):
    return current_user.to_dict()


# 路由：创建新用户（管理员权限）
# =============================================================================
# === 用户管理分组 ===
# =============================================================================


@auth.post("/users", response_model=UserResponse)
async def create_user(
    user_data: UserCreate, request: Request, current_user: User = Depends(get_admin_user), db: Session = Depends(get_db)
):
    # 检查用户名是否已存在
    existing_user = db.query(User).filter(User.username == user_data.username).first()
    if existing_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="用户名已存在",
        )

    # 创建新用户
    hashed_password = AuthUtils.hash_password(user_data.password)

    # 检查角色权限
    # 超级管理员可以创建任何类型的用户
    if user_data.role == "superadmin" and current_user.role != "superadmin":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="只有超级管理员才能创建超级管理员账户",
        )

    # 管理员只能创建普通用户
    if current_user.role == "admin" and user_data.role != "user":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="管理员只能创建普通用户账户",
        )

    new_user = User(username=user_data.username, password_hash=hashed_password, role=user_data.role)

    db.add(new_user)
    db.commit()
    db.refresh(new_user)

    # 记录操作
    log_operation(db, current_user.id, "创建用户", f"创建用户: {user_data.username}, 角色: {user_data.role}", request)

    return new_user.to_dict()


# 路由：获取所有用户（管理员权限）
@auth.get("/users", response_model=list[UserResponse])
async def read_users(
    skip: int = 0, limit: int = 100, current_user: User = Depends(get_admin_user), db: Session = Depends(get_db)
):
    users = db.query(User).offset(skip).limit(limit).all()
    return [user.to_dict() for user in users]


# 路由：获取特定用户信息（管理员权限）
@auth.get("/users/{user_id}", response_model=UserResponse)
async def read_user(user_id: int, current_user: User = Depends(get_admin_user), db: Session = Depends(get_db)):
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="用户不存在",
        )
    return user.to_dict()


# 路由：更新用户信息（管理员权限）
@auth.put("/users/{user_id}", response_model=UserResponse)
async def update_user(
    user_id: int,
    user_data: UserUpdate,
    request: Request,
    current_user: User = Depends(get_admin_user),
    db: Session = Depends(get_db),
):
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="用户不存在",
        )

    # 检查权限
    if user.role == "superadmin" and current_user.role != "superadmin":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="只有超级管理员才能修改超级管理员账户",
        )

    # 超级管理员账户不能被降级（只能由其他超级管理员修改）
    if user.role == "superadmin" and user_data.role and user_data.role != "superadmin" and current_user.id != user.id:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="不能降级超级管理员账户",
        )

    # 更新信息
    update_details = []

    if user_data.username is not None:
        # 检查用户名是否已被其他用户使用
        existing_user = db.query(User).filter(User.username == user_data.username, User.id != user_id).first()
        if existing_user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="用户名已存在",
            )
        user.username = user_data.username
        update_details.append(f"用户名: {user_data.username}")

    if user_data.password is not None:
        user.password_hash = AuthUtils.hash_password(user_data.password)
        update_details.append("密码已更新")

    if user_data.role is not None:
        user.role = user_data.role
        update_details.append(f"角色: {user_data.role}")

    db.commit()

    # 记录操作
    log_operation(db, current_user.id, "更新用户", f"更新用户ID {user_id}: {', '.join(update_details)}", request)

    return user.to_dict()


# 路由：删除用户（管理员权限）
@auth.delete("/users/{user_id}", response_model=dict)
async def delete_user(
    user_id: int, request: Request, current_user: User = Depends(get_admin_user), db: Session = Depends(get_db)
):
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="用户不存在",
        )

    # 检查权限
    if user.role == "superadmin":
        # 只有超级管理员可以删除超级管理员
        if current_user.role != "superadmin":
            raise HTTPException(
                status_code=status.HTTP_403_FORBIDDEN,
                detail="只有超级管理员才能删除超级管理员账户",
            )

        # 检查是否是最后一个超级管理员
        superadmin_count = db.query(User).filter(User.role == "superadmin").count()
        if superadmin_count <= 1:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="不能删除最后一个超级管理员账户",
            )

    # 不能删除自己的账户
    if user.id == current_user.id:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="不能删除自己的账户",
        )

    # 记录操作
    log_operation(
        db, current_user.id, "删除用户", f"删除用户: {user.username}, ID: {user.id}, 角色: {user.role}", request
    )

    # 删除用户
    db.delete(user)
    db.commit()

    return {"success": True, "message": "用户已删除"}