from fastapi import APIRouter, Depends, HTTPException, Query, status
from fastapi.responses import Response
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, and_
from fastcrud import FastCRUD
from datetime import timedelta, datetime
import redis.asyncio as redis

from database import get_db
from models import User
from schemas import (
    UserCreate,
    UserResponse,
    UserLogin,
    Token,
    UserCreateRequest,
    UserUpdate,
)
from utils.password import verify_password, get_password_hash
from utils.jwt import create_access_token
from config import app_settings
from utils.redis_client import get_redis, set_token_in_redis
from utils.captcha import create_captcha, validate_captcha
from middleware import get_current_user
from utils.like_filter import ilike_contains

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

# 创建FastCRUD实例
user_crud = FastCRUD(User, UserResponse)


@router.get("/captcha")
async def get_captcha(redis_conn: redis.Redis = Depends(get_redis)):
    """获取验证码图片"""
    # 创建验证码
    captcha_id, image_bytes = await create_captcha(redis_conn)
    
    # 返回验证码图片，同时在响应头中返回验证码ID
    response = Response(content=image_bytes, media_type="image/png")
    response.headers["X-Captcha-ID"] = captcha_id
    
    return response


@router.post("/login", response_model=Token)
async def login(
    user_data: UserLogin,
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """用户登录"""
    # 验证验证码
    is_captcha_valid = await validate_captcha(
        redis_conn, user_data.captcha_id, user_data.captcha_code
    )
    if not is_captcha_valid:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="验证码错误或已过期",
            headers={"WWW-Authenticate": "Bearer"},
        )

    # 查找用户
    result = await db.execute(select(User).filter(User.username == user_data.username))
    user = result.scalar_one_or_none()

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

    # 创建访问令牌
    access_token_expires = timedelta(minutes=app_settings.access_token_expire_minutes)
    access_token = create_access_token(
        data={"sub": str(user.id), "username": user.username},
        expires_delta=access_token_expires,
    )

    # 将令牌存储到Redis
    expire_seconds = int(access_token_expires.total_seconds())
    await set_token_in_redis(redis_conn, user.id, access_token, expire_seconds)

    # 更新用户最后登录时间
    user.lastlogintime = datetime.utcnow()
    await db.commit()

    return {"access_token": access_token, "token_type": "bearer"}


@router.post("/", response_model=UserResponse)
async def create_user(user_data: UserCreateRequest, db: AsyncSession = Depends(get_db)):
    """创建用户"""
    # 检查用户名是否已存在
    result = await db.execute(select(User).filter(User.username == user_data.username))
    existing_user = result.scalar_one_or_none()
    if existing_user:
        raise HTTPException(status_code=400, detail="用户名已存在")

    # 生成密码哈希值
    hashed_password = get_password_hash(user_data.password)

    # 准备创建数据
    create_data = user_data.model_dump()
    create_data["password_hash"] = hashed_password
    del create_data["password"]  # 删除明文密码
    # 转换为UserCreate模型
    user_data_create = UserCreate(**create_data)

    # 使用FastCRUD创建用户
    created_user = await user_crud.create(
        db, user_data_create, schema_to_select=UserResponse, return_as_model=True
    )
    return created_user


@router.get("/", response_model=list[UserResponse])
async def get_users(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
    username: str | None = Query(None, description="登录名，模糊匹配"),
    nickname: str | None = Query(None, description="昵称，模糊匹配"),
    email: str | None = Query(None, description="邮箱，模糊匹配"),
    phone: str | None = Query(None, description="手机，模糊匹配"),
):
    """分页列表用户；支持登录名、昵称、邮箱、手机的模糊查询与组合查询（AND）"""
    stmt = select(User)
    filters = []
    for col, raw in (
        (User.username, username),
        (User.nickname, nickname),
        (User.email, email),
        (User.phone, phone),
    ):
        cond = ilike_contains(col, raw)
        if cond is not None:
            filters.append(cond)
    if filters:
        stmt = stmt.where(and_(*filters))
    result = await db.execute(stmt)
    rows = result.scalars().all()
    return [UserResponse.model_validate(u) for u in rows]


@router.get("/me", response_model=UserResponse)
async def get_current_user_info(current_user: User = Depends(get_current_user)):
    """获取当前用户信息（须声明在 /{user_id} 之前，否则会被当成 id）"""
    return current_user


@router.get("/{user_id}", response_model=UserResponse)
async def get_user(
    user_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取单个用户"""
    user = await user_crud.get(db, id=user_id)
    if not user:
        raise HTTPException(status_code=404, detail="用户不存在")
    return user


@router.put("/{user_id}", response_model=UserResponse)
async def update_user(
    user_id: int,
    user_data: UserUpdate,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """更新用户"""
    # 检查用户名是否被其他用户使用
    result = await db.execute(
        select(User).filter(User.username == user_data.username, User.id != user_id)
    )
    existing_user = result.scalar_one_or_none()
    if existing_user:
        raise HTTPException(status_code=400, detail="用户名已存在")

    # 生成密码哈希值
    hashed_password = (
        get_password_hash(user_data.password) if user_data.password else None
    )

    # 准备更新数据
    update_data = user_data.model_dump()
    if hashed_password:
        update_data["password_hash"] = hashed_password
    del update_data["password"]  # 删除明文密码

    # 使用FastCRUD更新用户
    updated_user = await user_crud.update(
        db, update_data, id=user_id, schema_to_select=UserResponse, return_as_model=True
    )
    if not updated_user:
        raise HTTPException(status_code=404, detail="用户不存在")
    return updated_user


@router.delete("/{user_id}")
async def delete_user(
    user_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """删除用户"""
    # 检查用户是否存在
    result = await db.execute(select(User).filter(User.id == user_id))
    existing_user = result.scalar_one_or_none()
    if not existing_user:
        raise HTTPException(status_code=404, detail="用户不存在")
    elif existing_user.id == current_user.id:
        raise HTTPException(status_code=400, detail="不能删除当前登录用户")
    elif existing_user.role_id == 1:
        raise HTTPException(status_code=400, detail="不能删除管理员用户")
    else:
        # 使用FastCRUD删除用户
        deleted = await user_crud.delete(db, id=user_id)
        return {"message": "用户删除成功"}


@router.post("/logout")
async def logout(
    current_user: User = Depends(get_current_user),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """用户登出"""
    from utils.redis_client import delete_token_from_redis

    await delete_token_from_redis(redis_conn, current_user.id)
    return {"message": "登出成功"}