# ===========================================
# 班级操行分管理系统 - 权限验证中间件
# 
# 开发者: Canglan
# 联系方式: admin@sea-studio.top
# 版权归属: Sea Network Technology Studio
# 许可证: MIT License
# 
# 版权所有 © Sea Network Technology Studio
# ===========================================

from fastapi import Request
from typing import List, Optional, Callable, Dict, Any
from functools import wraps

from utils.response import forbidden_response
from utils.database import execute_one
from utils.logger import get_logger

logger = get_logger(__name__)


async def get_current_user(request: Request) -> Dict[str, Any]:
    """获取当前登录用户信息"""
    return {
        "user_id": getattr(request.state, 'user_id', None),
        "username": getattr(request.state, 'username', None),
        "user_type": getattr(request.state, 'user_type', None),
        "student_id": getattr(request.state, 'student_id', None),
        "role": getattr(request.state, 'role', None)
    }


async def get_current_user_id(request: Request) -> int:
    """获取当前用户ID"""
    return getattr(request.state, 'user_id', None)


class PermissionChecker:
    """权限检查器"""
    
    @staticmethod
    async def get_user_role(user_id: int) -> Optional[str]:
        """获取用户的管理员角色"""
        sql = "SELECT role_type FROM admin_roles WHERE user_id = %s LIMIT 1"
        result = await execute_one(sql, (user_id,))
        return result["role_type"] if result else None
    
    @staticmethod
    async def check_is_teacher(user_id: int) -> bool:
        """检查是否为班主任"""
        role = await PermissionChecker.get_user_role(user_id)
        return role == "班主任"
    
    @staticmethod
    async def check_is_monitor(user_id: int) -> bool:
        """检查是否为班长"""
        role = await PermissionChecker.get_user_role(user_id)
        return role == "班长"
    
    @staticmethod
    async def check_is_study_commissioner(user_id: int) -> bool:
        """检查是否为学习委员"""
        role = await PermissionChecker.get_user_role(user_id)
        return role == "学习委员"
    
    @staticmethod
    async def check_is_attendance_rep(user_id: int) -> bool:
        """检查是否为考勤委员"""
        role = await PermissionChecker.get_user_role(user_id)
        return role == "考勤委员"
    
    @staticmethod
    async def check_is_labor_rep(user_id: int) -> bool:
        """检查是否为劳动委员"""
        role = await PermissionChecker.get_user_role(user_id)
        return role == "劳动委员"
    
    @staticmethod
    async def check_can_manage_subjects(user_id: int) -> bool:
        """检查是否可以管理科目（班主任或学习委员）"""
        role = await PermissionChecker.get_user_role(user_id)
        return role in ["班主任", "学习委员"]
    
    @staticmethod
    async def get_user_class_id(user_id: int) -> Optional[int]:
        """
        获取用户关联的班级ID
        单班级系统，固定返回1
        """
        # 本系统为单班级设计，class_id 固定为 1
        return 1
    
    @staticmethod
    async def check_can_revoke(user_id: int, record_id: int) -> bool:
        """
        检查是否可以撤销扣分记录
        班主任：可以撤销任何记录
        班长：可以撤销任何记录
        其他：只能撤销自己的记录
        """
        sql = "SELECT recorder_id FROM conduct_records WHERE record_id = %s"
        record = await execute_one(sql, (record_id,))
        if not record:
            return False
        role = await PermissionChecker.get_user_role(user_id)
        if role in ["班主任", "班长"]:
            return True
        return record["recorder_id"] == user_id


def require_auth(func: Callable):
    """需要认证的装饰器"""
    @wraps(func)
    async def wrapper(*args, **kwargs):
        request = kwargs.get('request')
        if not request or not hasattr(request.state, 'user_id'):
            return forbidden_response("请先登录")
        return await func(*args, **kwargs)
    return wrapper


def require_role(roles: List[str]):
    """需要特定角色的装饰器"""
    def decorator(func: Callable):
        @wraps(func)
        async def wrapper(*args, **kwargs):
            request = kwargs.get('request')
            if not request or not hasattr(request.state, 'user_id'):
                return forbidden_response("请先登录")
            user_id = request.state.user_id
            user_role = await PermissionChecker.get_user_role(user_id)
            if user_role not in roles:
                return forbidden_response(f"需要{','.join(roles)}权限")
            return await func(*args, **kwargs)
        return wrapper
    return decorator


def require_teacher(func: Callable):
    """需要班主任权限的装饰器"""
    @wraps(func)
    async def wrapper(*args, **kwargs):
        request = kwargs.get('request')
        if not request or not hasattr(request.state, 'user_id'):
            return forbidden_response("请先登录")
        is_teacher = await PermissionChecker.check_is_teacher(request.state.user_id)
        if not is_teacher:
            return forbidden_response("需要班主任权限")
        return await func(*args, **kwargs)
    return wrapper


def require_monitor(func: Callable):
    """需要班长权限的装饰器"""
    @wraps(func)
    async def wrapper(*args, **kwargs):
        request = kwargs.get('request')
        if not request or not hasattr(request.state, 'user_id'):
            return forbidden_response("请先登录")
        is_monitor = await PermissionChecker.check_is_monitor(request.state.user_id)
        if not is_monitor:
            return forbidden_response("需要班长权限")
        return await func(*args, **kwargs)
    return wrapper


def require_study_commissioner(func: Callable):
    """需要学习委员权限的装饰器"""
    @wraps(func)
    async def wrapper(*args, **kwargs):
        request = kwargs.get('request')
        if not request or not hasattr(request.state, 'user_id'):
            return forbidden_response("请先登录")
        is_study = await PermissionChecker.check_is_study_commissioner(request.state.user_id)
        if not is_study:
            return forbidden_response("需要学习委员权限")
        return await func(*args, **kwargs)
    return wrapper