from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status
from rest_framework.permissions import AllowAny
from django.views.decorators.csrf import csrf_exempt
from django.utils.decorators import method_decorator
from api.utils.auth import ThirdPartyAuth, ThirdPartyUserManager
from django.contrib.auth.models import User
import logging

logger = logging.getLogger(__name__)


@method_decorator(csrf_exempt, name='dispatch')
class TokenValidateView(APIView):
    """
    Token验证接口
    用户可以通过此接口验证Token是否有效，并获取用户信息
    """
    permission_classes = [AllowAny]  # 允许任何人访问此接口
    
    def post(self, request):
        """
        验证Token
        
        支持的参数传递方式：
        1. JSON: {"token": "your_token"}
        2. Form data: token=your_token
        3. URL参数: ?token=your_token
        4. Header: Authorization: Token your_token
        """
        # 获取Token
        token = self.get_token_from_request(request)
        
        if not token:
            return Response({
                'valid': False,
                'error': 'Token参数缺失',
                'message': '请提供Token参数。支持的方式：1) JSON: {"token": "your_token"} 2) Form data: token=your_token 3) URL参数: ?token=your_token 4) Header: Authorization: Token your_token',
                'example': {
                    'curl_header': 'curl -H "Authorization: Token 0c47b3d5b1aa561a5032f50e95bf069afa9a9e55" http://your-domain/api/token/validate/',
                    'curl_param': 'curl -X POST http://your-domain/api/token/validate/?token=0c47b3d5b1aa561a5032f50e95bf069afa9a9e55',
                    'curl_json': 'curl -X POST -H "Content-Type: application/json" -d \'{"token":"0c47b3d5b1aa561a5032f50e95bf069afa9a9e55"}\' http://your-domain/api/token/validate/'
                }
            }, status=status.HTTP_400_BAD_REQUEST)
        
        # 验证Token
        validation_result = ThirdPartyAuth.validate_token(token)
        
        if not validation_result['valid']:
            return Response({
                'valid': False,
                'error': 'Token验证失败',
                'message': validation_result.get('message', 'Token无效或已过期'),
                'token_preview': f"{token[:8]}..." if len(token) > 8 else token
            }, status=status.HTTP_401_UNAUTHORIZED)
        
        # Token有效，获取用户信息
        user_name = validation_result.get('user_name')
        
        if not user_name:
            return Response({
                'valid': False,
                'error': '用户信息获取失败',
                'message': '第三方API返回的数据中没有用户名信息'
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
        
        # 检查本地是否已有用户
        local_user = ThirdPartyUserManager.get_user_by_third_party_username(user_name)
        local_user_exists = local_user is not None
        
        return Response({
            'valid': True,
            'message': 'Token验证成功',
            'user_info': {
                'third_party_username': user_name,
                'local_user_exists': local_user_exists,
                'local_username': local_user.username if local_user else None,
                'local_user_id': local_user.id if local_user else None
            },
            'token_info': {
                'token_preview': f"{token[:8]}..." if len(token) > 8 else token,
                'token_length': len(token)
            },
            'next_steps': {
                'message': '现在您可以使用此Token访问其他API接口',
                'note': '如果local_user_exists为false，系统将在您首次使用其他API时自动创建本地用户账户和数据目录'
            }
        }, status=status.HTTP_200_OK)
    
    def get(self, request):
        """
        GET方法也支持Token验证（通过URL参数）
        """
        return self.post(request)
    
    def get_token_from_request(self, request):
        """
        从请求中获取Token
        """
        # 1. 从JSON数据获取
        if hasattr(request, 'data') and 'token' in request.data:
            return request.data.get('token')
        
        # 2. 从Authorization header获取
        auth_header = request.META.get('HTTP_AUTHORIZATION', '')
        if auth_header.startswith('Token '):
            return auth_header[6:]
        if auth_header.startswith('Bearer '):
            return auth_header[7:]
        
        # 3. 从URL参数获取
        token = request.GET.get('token')
        if token:
            return token
        
        # 4. 从POST form data获取
        if hasattr(request, 'POST') and 'token' in request.POST:
            return request.POST.get('token')
        
        return None


@method_decorator(csrf_exempt, name='dispatch')
class UserInfoView(APIView):
    """
    获取当前用户信息的接口
    需要有效的Token
    """
    
    def get(self, request):
        """
        获取当前用户信息
        """
        # 通过认证系统已经验证了Token，用户信息在request.user中
        user = request.user
        
        if not user or not user.is_authenticated:
            return Response({
                'error': '用户未认证',
                'message': '请提供有效的Token'
            }, status=status.HTTP_401_UNAUTHORIZED)
        
        # 获取第三方用户映射信息
        try:
            from api.models import ThirdPartyUserMapping
            mapping = ThirdPartyUserMapping.objects.get(user=user)
            third_party_info = {
                'third_party_user_id': mapping.third_party_user_id,
                'third_party_username': mapping.third_party_username,
                'created_at': mapping.created_at,
                'updated_at': mapping.updated_at
            }
        except ThirdPartyUserMapping.DoesNotExist:
            third_party_info = None
        
        # 获取用户的项目信息
        projects_count = user.projects.count()
        
        return Response({
            'user_info': {
                'local_user_id': user.id,
                'local_username': user.username,
                'email': user.email,
                'first_name': user.first_name,
                'last_name': user.last_name,
                'date_joined': user.date_joined,
                'last_login': user.last_login
            },
            'third_party_info': third_party_info,
            'statistics': {
                'projects_count': projects_count
            },
            'data_directories': {
                'user_base_dir': f'/media/users/{user.id}/',
                'projects_dir': f'/media/users/{user.id}/projects/'
            }
        }, status=status.HTTP_200_OK)