from fastapi import APIRouter, Depends, HTTPException, Query, status, Request
from fastapi.responses import Response, HTMLResponse
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, and_, or_
from fastcrud import FastCRUD
from datetime import timedelta, datetime
from uuid import uuid4
import json
import redis.asyncio as redis

from database import get_db
from models import User, SystemSetting
from schemas import (
    UserCreate,
    UserResponse,
    UserLogin,
    Token,
    UserCreateRequest,
    UserUpdate,
    PhoneSendCodeRequest,
    PhoneSendCodeResponse,
    PhoneRegisterRequest,
    EmailRegisterInitRequest,
    EmailRegisterInitResponse,
    RegisterSuccessResponse,
)
from utils.password import verify_password, get_password_hash
from utils.jwt import create_access_token, decode_token
from config import app_settings
from utils.redis_client import (
    get_redis, set_token_in_redis, delete_token_from_redis,
    save_sms_code, get_and_delete_sms_code,
    save_pending_registration, get_and_delete_pending_registration,
)
from utils.captcha import create_captcha, validate_captcha
from middleware import get_current_user
from utils.like_filter import ilike_contains
from utils.log_utils import get_client_ip, get_user_agent, save_login_log, create_operation_log
from utils.sms import generate_sms_code, send_sms_code
from utils.email import send_verification_email

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,
    request: Request,
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """用户登录"""
    ip = get_client_ip(request)
    ua = get_user_agent(request)

    # 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:
        await save_login_log(db, user_data.username, ip, ua, "failure", "验证码错误或已过期")
        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（支持用户名/邮箱/手机号）
    login_id = user_data.username
    result = await db.execute(
        select(User).filter(
            or_(
                User.username == login_id,
                User.email == login_id,
                User.phone == login_id,
            )
        )
    )
    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):
        await save_login_log(db, login_id, ip, ua, "failure", "用户名或密码错误")
        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()

    # 记录登录成功日志
    await save_login_log(db, user.username, ip, ua, "success", None)

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


@router.post("/", response_model=UserResponse)
async def create_user(
    user_data: UserCreateRequest, 
    request: Request,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """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
    )

    # 记录操作日志
    await create_operation_log(
        db, current_user.id, current_user.username, "create", "user",
        created_user.id, created_user.username,
        {"username": user_data.username, "nickname": user_data.nickname},
        get_client_ip(request), get_user_agent(request),
    )
    await db.commit()

    return created_user


@router.post("/search", response_model=list[UserResponse])
async def search_users(
    query: dict = {},
    request: Request = None,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """分页列表用户（POST方式）；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, key in (
        (User.username, "username"),
        (User.nickname, "nickname"),
        (User.email, "email"),
        (User.phone, "phone"),
    ):
        raw = query.get(key)
        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()

    # 记录查询日志
    await create_operation_log(
        db, current_user.id, current_user.username, "search", "user",
        None, None, {"filters": {k: v for k, v in query.items() if v}},
        get_client_ip(request), get_user_agent(request),
    )
    await db.commit()

    return [UserResponse.model_validate(u) for u in rows]


@router.get("/me", response_model=UserResponse)
async def get_current_user_info(
    request: Request,
    db: AsyncSession = Depends(get_db),
    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）"""
    # 记录查询日志
    await create_operation_log(
        db, current_user.id, current_user.username, "search", "user",
        current_user.id, current_user.username, None,
        get_client_ip(request), get_user_agent(request),
    )
    await db.commit()
    return current_user


@router.get("/{user_id}", response_model=UserResponse)
async def get_user(
    user_id: int,
    request: Request,
    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")

    # 记录查询日志
    await create_operation_log(
        db, current_user.id, current_user.username, "search", "user",
        user_id, user.username, None,
        get_client_ip(request), get_user_agent(request),
    )
    await db.commit()

    return user


@router.put("/{user_id}", response_model=UserResponse)
async def update_user(
    user_id: int,
    user_data: UserUpdate,
    request: Request,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """更新用户"""
    # 获取原用户数据用于记录变更
    result = await db.execute(select(User).filter(User.id == user_id))
    old_user = result.scalar_one_or_none()
    if not old_user:
        raise HTTPException(status_code=404, detail="用户不存在")

    # 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")

    # 记录操作日志（计算变更字段）
    changed = {}
    for field in ["username", "nickname", "email", "phone", "role_id"]:
        old_val = getattr(old_user, field, None)
        new_val = update_data.get(field)
        if old_val != new_val:
            changed[field] = {"old": old_val, "new": new_val}
    await create_operation_log(
        db, current_user.id, current_user.username, "update", "user",
        user_id, old_user.username, changed if changed else None,
        get_client_ip(request), get_user_agent(request),
    )
    await db.commit()

    return updated_user


@router.delete("/{user_id}")
async def delete_user(
    user_id: int,
    request: Request,
    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:
        # 记录操作日志（删除前记录被删用户信息）
        await create_operation_log(
            db, current_user.id, current_user.username, "delete", "user",
            user_id, existing_user.username,
            {"username": existing_user.username, "nickname": existing_user.nickname},
            get_client_ip(request), get_user_agent(request),
        )
        # 使用FastCRUD删除用户
        deleted = await user_crud.delete(db, id=user_id)
        return {"message": "用户删除成功"}


# ========================================
# 用户注册
# ========================================


@router.post("/register/send-code", response_model=PhoneSendCodeResponse)
async def send_register_sms_code(
    req: PhoneSendCodeRequest,
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """发送手机注册验证码"""
    # 检查短信注册开关
    result = await db.execute(select(SystemSetting).filter(SystemSetting.key == "启用手机短信注册"))
    sms_setting = result.scalar_one_or_none()
    if not sms_setting or sms_setting.value != "true":
        raise HTTPException(status_code=403, detail="手机短信注册功能未启用")

    # 检查手机号是否已被注册
    result = await db.execute(select(User).filter(User.phone == req.phone))
    if result.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="该手机号已被注册")

    # 频率限制：60秒内不能重复发送
    ttl = await redis_conn.ttl(f"sms_code:{req.phone}")
    if ttl > 240:
        raise HTTPException(status_code=429, detail="验证码已发送，请60秒后再试")

    # 生成验证码并存入 Redis
    code = generate_sms_code()
    await save_sms_code(redis_conn, req.phone, code)

    # 发送短信
    await send_sms_code(req.phone, code)

    return PhoneSendCodeResponse()


@router.post("/register/phone", response_model=RegisterSuccessResponse)
async def register_by_phone(
    req: PhoneRegisterRequest,
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """通过手机号注册"""
    # 检查短信注册开关
    result = await db.execute(select(SystemSetting).filter(SystemSetting.key == "启用手机短信注册"))
    sms_setting = result.scalar_one_or_none()
    if not sms_setting or sms_setting.value != "true":
        raise HTTPException(status_code=403, detail="手机短信注册功能未启用")

    # 检查用户名是否已存在
    result = await db.execute(select(User).filter(User.username == req.username))
    if result.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="用户名已存在")

    # 检查手机号是否已被注册
    result = await db.execute(select(User).filter(User.phone == req.phone))
    if result.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="该手机号已被注册")

    # 验证短信验证码
    stored_code = await get_and_delete_sms_code(redis_conn, req.phone)
    if stored_code is None:
        raise HTTPException(status_code=400, detail="验证码已过期，请重新发送")
    if stored_code != req.code:
        raise HTTPException(status_code=400, detail="验证码错误")

    # 创建用户
    hashed_pw = get_password_hash(req.password)
    new_user = User(
        username=req.username,
        nickname=req.nickname,
        phone=req.phone,
        password_hash=hashed_pw,
        role_id=2,
    )
    db.add(new_user)
    await db.commit()
    await db.refresh(new_user)

    return RegisterSuccessResponse(
        id=new_user.id, username=new_user.username, nickname=new_user.nickname
    )


@router.post("/register/email/init", response_model=EmailRegisterInitResponse)
async def init_email_registration(
    req: EmailRegisterInitRequest,
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """初始化邮箱注册（发送验证邮件）"""
    # 检查邮箱注册开关
    result = await db.execute(select(SystemSetting).filter(SystemSetting.key == "启用邮箱注册"))
    email_setting = result.scalar_one_or_none()
    if not email_setting or email_setting.value != "true":
        raise HTTPException(status_code=403, detail="邮箱注册功能未启用")

    # 检查用户名是否已存在
    result = await db.execute(select(User).filter(User.username == req.username))
    if result.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="用户名已存在")

    # 检查邮箱是否已被注册
    result = await db.execute(select(User).filter(User.email == req.email))
    if result.scalar_one_or_none():
        raise HTTPException(status_code=400, detail="该邮箱已被注册")

    # 哈希密码后存储待注册数据
    hashed_pw = get_password_hash(req.password)
    token_id = str(uuid4())
    pending_data = json.dumps({
        "username": req.username,
        "nickname": req.nickname,
        "email": req.email,
        "password_hash": hashed_pw,
    })
    await save_pending_registration(redis_conn, token_id, pending_data)

    # 生成 JWT 验证令牌
    jwt_token = create_access_token(
        data={"sub": token_id, "type": "email_verify", "email": req.email},
        expires_delta=timedelta(minutes=30),
    )

    # 发送验证邮件
    await send_verification_email(req.email, jwt_token)

    return EmailRegisterInitResponse()


@router.get("/verify-email")
async def verify_email(
    token: str = Query(..., description="验证令牌"),
    db: AsyncSession = Depends(get_db),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """验证邮箱并完成注册"""
    # 检查邮箱注册开关
    result = await db.execute(select(SystemSetting).filter(SystemSetting.key == "启用邮箱注册"))
    email_setting = result.scalar_one_or_none()
    if not email_setting or email_setting.value != "true":
        return HTMLResponse("<h2>邮箱注册功能未启用</h2>", status_code=403)

    # 解析 JWT
    payload = decode_token(token)
    if payload is None:
        return HTMLResponse("<h2>验证链接无效或已过期</h2>", status_code=400)
    if payload.get("type") != "email_verify":
        return HTMLResponse("<h2>无效的验证链接</h2>", status_code=400)

    token_id = payload.get("sub")
    pending_json = await get_and_delete_pending_registration(redis_conn, token_id)
    if pending_json is None:
        return HTMLResponse("<h2>验证链接已过期或已使用</h2>", status_code=400)

    data = json.loads(pending_json)

    # 再次检查用户名和邮箱唯一性
    result = await db.execute(select(User).filter(User.username == data["username"]))
    if result.scalar_one_or_none():
        return HTMLResponse("<h2>该用户名已被注册</h2>", status_code=400)

    result = await db.execute(select(User).filter(User.email == data["email"]))
    if result.scalar_one_or_none():
        return HTMLResponse("<h2>该邮箱已被注册</h2>", status_code=400)

    # 创建用户
    new_user = User(
        username=data["username"],
        nickname=data["nickname"],
        email=data["email"],
        password_hash=data["password_hash"],
        role_id=2,
    )
    db.add(new_user)
    await db.commit()
    await db.refresh(new_user)

    return HTMLResponse(f"""<!DOCTYPE html>
<html><head><meta charset="utf-8"></head>
<body style="font-family:Arial,sans-serif;text-align:center;padding:60px 20px;">
  <h1 style="color:#67c23a;">✅ 注册成功</h1>
  <p>欢迎 <b>{new_user.username}</b>，您的账号已创建完成。</p>
  <p>请返回应用使用 <b>用户名、邮箱或手机号</b> 登录。</p>
</body></html>""")


@router.post("/logout")
async def logout(
    request: Request,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
    redis_conn: redis.Redis = Depends(get_redis),
):
    """用户登出"""
    await delete_token_from_redis(redis_conn, current_user.id)

    # 记录登出日志
    await save_login_log(
        db, current_user.username,
        get_client_ip(request), get_user_agent(request),
        "success", None,
    )
    return {"message": "登出成功"}