"""
路由层装饰器

提供权限检查、参数验证等装饰器
注意：基础的 login_required 和 admin_required 使用 app.services.auth.decorators
"""
from functools import wraps
from flask import jsonify, g, request
from app.models.database.models import CategoryAdmin, Role


def category_permission_required(min_role='viewer'):
    """
    方向权限装饰器 - 支持三级权限
    
    权限级别:
    - viewer: 只读权限，可查看配置
    - editor: 编辑权限，可修改配置
    - owner: 管理权限，可管理权限和删除
    
    Args:
        min_role: 最低要求的权限级别
        
    Usage:
        @category_permission_required('editor')
        def update_category(category_id):
            pass
    """
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            # 获取当前用户
            if not hasattr(g, 'user') or not g.user:
                return jsonify({'success': False, 'error': '请先登录'}), 401

            user = g.user

            # 系统管理员拥有所有权限
            if user.role == Role.ADMIN:
                return f(*args, **kwargs)

            # 获取 category_id（从路径参数或请求参数）
            category_id = kwargs.get('category_id') or request.view_args.get('category_id')
            if not category_id:
                # 如果没有 category_id，说明不是方向相关的路由，直接放行
                return f(*args, **kwargs)

            # 获取用户在该方向的角色
            admin_record = CategoryAdmin.query.filter_by(
                category_id=category_id,
                user_id=user.id
            ).first()

            if not admin_record:
                return jsonify({'success': False, 'error': '没有该方向的访问权限'}), 403

            # 权限级别映射
            role_levels = {'viewer': 1, 'editor': 2, 'owner': 3}
            user_level = role_levels.get(admin_record.role, 0)
            required_level = role_levels.get(min_role, 1)

            if user_level < required_level:
                role_names = {'viewer': '查看', 'editor': '编辑', 'owner': '管理'}
                return jsonify({
                    'success': False, 
                    'error': f'需要{role_names.get(min_role, min_role)}权限'
                }), 403

            return f(*args, **kwargs)
        return decorated_function
    return decorator


def challenge_owner_required(f):
    """
    题目所有者权限装饰器
    
    检查当前用户是否是题目的创建者或管理员
    
    Usage:
        @challenge_owner_required
        def delete_challenge(challenge_id):
            pass
    """
    @wraps(f)
    def decorated_function(*args, **kwargs):
        # 获取当前用户
        if not hasattr(g, 'user') or not g.user:
            return jsonify({'success': False, 'error': '请先登录'}), 401

        user = g.user

        # 管理员拥有所有权限
        if user.role == Role.ADMIN:
            return f(*args, **kwargs)

        # 获取 challenge_id
        challenge_id = kwargs.get('challenge_id') or request.view_args.get('challenge_id')
        if not challenge_id:
            return jsonify({'success': False, 'error': '缺少题目ID'}), 400

        # 检查题目所有权
        try:
            from app.models.database.operations import get_challenge_record
            challenge = get_challenge_record(int(challenge_id))
            
            if not challenge:
                return jsonify({'success': False, 'error': '题目不存在'}), 404
            
            if challenge.get('user_id') != user.id:
                return jsonify({'success': False, 'error': '您没有权限操作此题目'}), 403
                
        except Exception as e:
            return jsonify({'success': False, 'error': f'权限检查失败: {str(e)}'}), 500

        return f(*args, **kwargs)
    return decorated_function


def validate_json(*required_fields):
    """
    JSON 数据验证装饰器
    
    Args:
        *required_fields: 必需的字段名
        
    Usage:
        @validate_json('name', 'email')
        def create_user():
            data = request.get_json()
            # data 已经验证包含 name 和 email
    """
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            if not request.is_json:
                return jsonify({
                    'success': False,
                    'error': '请求必须是 JSON 格式'
                }), 400
            
            data = request.get_json()
            if not data:
                return jsonify({
                    'success': False,
                    'error': '请求数据不能为空'
                }), 400
            
            # 检查必需字段
            missing_fields = [field for field in required_fields if field not in data]
            if missing_fields:
                return jsonify({
                    'success': False,
                    'error': f'缺少必需字段: {", ".join(missing_fields)}'
                }), 400
            
            return f(*args, **kwargs)
        return decorated_function
    return decorator