from functools import wraps
from flask import request, jsonify
from models import db, UserApiKey, ApiKeyDailyStat
from datetime import datetime, date


def get_api_key_from_request():
    """从请求中获取 API Key"""
    # 优先从 Header 获取
    api_key = request.headers.get('X-API-Key')
    if api_key:
        return api_key

    # 其次从 Authorization Bearer 获取
    auth_header = request.headers.get('Authorization')
    if auth_header and auth_header.startswith('Bearer '):
        return auth_header[7:]

    # 最后从查询参数获取
    return request.args.get('api_key')


def validate_api_key(api_key):
    """
    验证 API Key
    返回: (is_valid, key_obj_or_error_msg)
    """
    if not api_key:
        return False, 'API Key 不能为空'

    key_obj = UserApiKey.query.filter_by(api_key=api_key).first()

    if not key_obj:
        return False, 'API Key 无效'

    if not key_obj.is_active:
        return False, 'API Key 已被禁用'

    if not key_obj.user.is_active:
        return False, '用户账号已被禁用'

    # 检查每日限额
    today_stat = ApiKeyDailyStat.query.filter_by(
        api_key_id=key_obj.id,
        date=date.today()
    ).first()

    if today_stat and today_stat.call_count >= key_obj.daily_limit:
        return False, f'已达到每日调用限额（{key_obj.daily_limit}次）'

    return True, key_obj


def record_api_call(key_obj, ip_address, success=True):
    """记录 API 调用"""
    # 更新 Key 统计
    key_obj.total_calls += 1
    key_obj.last_used_at = datetime.utcnow()
    key_obj.last_used_ip = ip_address

    # 更新每日统计
    today_stat = ApiKeyDailyStat.query.filter_by(
        api_key_id=key_obj.id,
        date=date.today()
    ).first()

    if not today_stat:
        today_stat = ApiKeyDailyStat(
            api_key_id=key_obj.id,
            date=date.today()
        )
        db.session.add(today_stat)

    today_stat.call_count += 1
    if success:
        today_stat.success_count += 1
    else:
        today_stat.fail_count += 1

    db.session.commit()


def api_key_required(f):
    """API Key 鉴权装饰器"""
    @wraps(f)
    def decorated_function(*args, **kwargs):
        api_key = get_api_key_from_request()

        is_valid, result = validate_api_key(api_key)

        if not is_valid:
            return jsonify({
                'success': False,
                'error': {
                    'code': 'UNAUTHORIZED',
                    'message': result
                }
            }), 401

        # 将 key 对象传递给视图函数
        request.api_key_obj = result
        return f(*args, **kwargs)

    return decorated_function