"""
管理员用户管理服务

提供用户列表查询、详情查询、状态变更等功能
Requirements: 2.1-2.5, 3.1-3.5, 4.1-4.5, 5.1-5.5, 6.1-6.4
"""
import secrets
import string
from datetime import datetime, date
from typing import Optional, List, Tuple

from sqlalchemy.orm import Session
from sqlalchemy import and_, or_, desc, asc, func

from app.models.user import User
from app.models.api_call_log import ApiCallLog
from app.services.auth_service import AuthService
from app.schemas.admin_schema import (
    UserListParams, UserListItem, UserDetailResponse,
    UserUsageStats
)


class AdminUserService:
    """管理员用户管理服务类"""

    def __init__(self, db: Session):
        self.db = db

    def list_users(self, params: UserListParams) -> Tuple[List[UserListItem], int]:
        """获取用户列表，支持搜索、筛选、排序、分页"""
        query = self.db.query(User)

        # 搜索条件
        if params.keyword:
            keyword = f"%{params.keyword}%"
            query = query.filter(or_(
                User.id.ilike(keyword),
                User.username.ilike(keyword),
                User.nickname.ilike(keyword),
                User.real_name.ilike(keyword),
                User.phone.ilike(keyword),
                User.email.ilike(keyword)
            ))

        # 状态筛选
        if params.status:
            query = query.filter(User.status == params.status)

        # 注册时间筛选
        if params.register_start:
            query = query.filter(User.registration_date >= params.register_start)
        if params.register_end:
            query = query.filter(User.registration_date <= params.register_end)

        # 总数
        total = query.count()

        # 排序
        sort_column = User.created_at
        if params.sort_by == "created_at":
            sort_column = User.created_at

        if params.sort_order == "asc":
            query = query.order_by(asc(sort_column))
        else:
            query = query.order_by(desc(sort_column))

        # 分页
        users = query.offset((params.page - 1) * params.size).limit(params.size).all()

        # 转换为响应格式
        result = []
        for user in users:
            result.append(UserListItem(
                id=user.id,
                username=user.username,
                nickname=user.nickname,
                phone=user.phone,
                registration_date=user.registration_date,
                status=user.status,
                is_verified=user.is_verified,
                real_name=user.real_name
            ))

        return result, total

    def get_user_detail(self, user_id: str) -> Optional[UserDetailResponse]:
        """获取用户详情"""
        user = self.db.query(User).filter(User.id == user_id).first()
        if not user:
            return None

        return UserDetailResponse(
            id=user.id,
            username=user.username,
            nickname=user.nickname,
            phone=user.phone,
            email=user.email,
            avatar=user.avatar,
            registration_date=user.registration_date,
            status=user.status
        )

    def get_user_usage_stats(self, user_id: str) -> UserUsageStats:
        """获取用户使用统计"""
        # API调用统计
        api_stats = self.db.query(
            func.count(ApiCallLog.id),
            func.coalesce(func.sum(ApiCallLog.input_tokens), 0),
            func.coalesce(func.sum(ApiCallLog.output_tokens), 0)
        ).filter(ApiCallLog.user_id == user_id).first()

        api_call_count = api_stats[0] if api_stats else 0
        api_input_tokens = int(api_stats[1]) if api_stats else 0
        api_output_tokens = int(api_stats[2]) if api_stats else 0

        return UserUsageStats(
            conversation_count=0,
            token_consumed=0,
            image_count=0,
            audio_count=0,
            audio_duration=0,
            video_count=0,
            api_call_count=api_call_count,
            api_input_tokens=api_input_tokens,
            api_output_tokens=api_output_tokens
        )

    def update_user_status(self, user_id: str, status: str) -> bool:
        """更新用户状态"""
        user = self.db.query(User).filter(User.id == user_id).first()
        if not user:
            raise ValueError("USER_NOT_FOUND")

        if user.status == status:
            raise ValueError("STATUS_UNCHANGED")

        user.status = status
        self.db.commit()
        return True

    def reset_password(self, user_id: str) -> str:
        """重置用户密码，返回新密码"""
        user = self.db.query(User).filter(User.id == user_id).first()
        if not user:
            raise ValueError("USER_NOT_FOUND")

        # 生成8位随机密码
        alphabet = string.ascii_letters + string.digits
        new_password = ''.join(secrets.choice(alphabet) for _ in range(8))

        # 更新密码哈希
        user.password_hash = AuthService.hash_password(new_password)
        self.db.commit()

        return new_password