# apps/accounts/views.py
from django.contrib.auth import authenticate, login, logout
from django.core.exceptions import ValidationError
from django.contrib.auth.hashers import check_password
from django.utils.decorators import method_decorator
from django.views.decorators.csrf import csrf_exempt
from rest_framework.views import APIView
from rest_framework.decorators import api_view, permission_classes
from rest_framework.response import Response
from rest_framework import status
from rest_framework.permissions import AllowAny, IsAuthenticated, IsAdminUser
from rest_framework.authtoken.models import Token
from django.db.models import Q
from django.shortcuts import get_object_or_404
import uuid
import logging
import traceback
from apps.accounts.models import User
from apps.accounts.services.auth_service import (
    authenticate_user, create_user, generate_token, delete_token
)
from apps.accounts.services.utils import (
     format_user_response, validate_uuid_param
)


logger = logging.getLogger(__name__)

@method_decorator(csrf_exempt, name='dispatch')
class LoginView(APIView):
    """用户登录视图"""
    authentication_classes = []  # 清空认证类
    permission_classes = [AllowAny]
    
    def post(self, request):
        try:
            username = request.data.get('username')
            password = request.data.get('password')
            
            # 参数验证
            if not username or not password:
                return Response({
                    "code": 400,
                    "message": "请提供用户名和密码",
                    "data": None
                }, status=status.HTTP_400_BAD_REQUEST)

            # 验证用户
            user = authenticate_user(request, username, password)
            
            if user is not None:
                # 获取或创建token
                token = generate_token(user)
                
                # 登录用户（可选）
                login(request, user)
                
                return Response({
                    "code": 200,
                    "message": "登录成功",
                    "data": {
                        "id": str(user.id),
                        "username": user.username,
                        "email": user.email,
                        "name": user.name,
                        "role": user.role,
                        "department": user.department,
                        "group": user.group,
                        "token": token
                    }
                })
            else:
                return Response({
                    "code": 401,
                    "message": "用户名或密码错误",
                    "data": None
                }, status=status.HTTP_401_UNAUTHORIZED)

        except Exception as e:
            logger.error(f"登录失败: {str(e)}")
            logger.error(f"错误类型: {type(e)}")
            logger.error(f"错误堆栈: {traceback.format_exc()}")
            
            return Response({
                "code": 500,
                "message": "登录失败，请稍后重试",
                "data": None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@method_decorator(csrf_exempt, name='dispatch')
class RegisterView(APIView):
    """用户注册视图"""
    permission_classes = [AllowAny]

    def post(self, request):
        try:
            data = request.data
            
            # 检查必填字段
            required_fields = ['username', 'password', 'email', 'role', 'name']
            for field in required_fields:
                if not data.get(field):
                    return Response({
                        "code": 400,
                        "message": f"缺少必填字段: {field}",
                        "data": None
                    }, status=status.HTTP_400_BAD_REQUEST)

            # 验证角色
            valid_roles = ['admin', 'leader', 'member']
            roles_str = ', '.join(valid_roles)  # 先构造角色字符串
            if data['role'] not in valid_roles:
                return Response({
                    "code": 400,
                    "message": f"无效的角色，必须是: {roles_str}",
                    "data": None
                }, status=status.HTTP_400_BAD_REQUEST)

            # 创建用户
            user = create_user(data)
            if isinstance(user, dict):  # 错误响应
                return Response(user, status=user.get('status', status.HTTP_400_BAD_REQUEST))

            # 生成认证令牌
            token = generate_token(user)

            return Response({
                "code": 200,
                "message": "注册成功",
                "data": {
                    "id": str(user.id),
                    "username": user.username,
                    "email": user.email,
                    "role": user.role,
                    "department": user.department,
                    "name": user.name,
                    "group": user.group,
                    "token": token,
                    "created_at": user.date_joined.strftime('%Y-%m-%d %H:%M:%S')
                }
            }, status=status.HTTP_201_CREATED)

        except Exception as e:
            logger.error(f"注册失败: {str(e)}")
            logger.error(f"错误类型: {type(e)}")
            logger.error(f"错误堆栈: {traceback.format_exc()}")
            return Response({
                "code": 500,
                "message": f"注册失败: {str(e)}",
                "data": None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@method_decorator(csrf_exempt, name='dispatch')
class LogoutView(APIView):
    """用户登出视图"""
    permission_classes = [IsAuthenticated]
    
    def post(self, request):
        try:
            # 删除用户的token
            delete_token(request.user)
            # 执行django的登出
            logout(request)
            
            return Response({
                "code": 200,
                "message": "登出成功",
                "data": None
            })
        except Exception as e:
            logger.error(f"登出失败: {str(e)}")
            logger.error(traceback.format_exc())
            return Response({
                "code": 500,
                "message": f"登出失败: {str(e)}",
                "data": None
            }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@api_view(['GET', 'PUT'])
@permission_classes([IsAuthenticated])
def user_profile(request):
    """
    获取或更新当前登录用户信息
    """
    try:
        if request.method == 'GET':
            user = request.user
            if not user.is_authenticated:
                return Response({
                    'code': 401,
                    'message': '用户未认证',
                    'data': None
                }, status=status.HTTP_401_UNAUTHORIZED)
                
            data = {
                'id': str(user.id),
                'username': user.username,
                'email': user.email,
                'name': user.name,
                'role': user.role,
                'department': user.department,
                'group': user.group,
                'date_joined': user.date_joined.strftime('%Y-%m-%d %H:%M:%S')
            }
            return Response({
                'code': 200,
                'message': '获取用户信息成功',
                'data': data
            })
        
        elif request.method == 'PUT':
            try:
                if not request.data:
                    return Response({
                        'code': 400,
                        'message': '请求数据为空或格式错误',
                        'data': None
                    }, status=status.HTTP_400_BAD_REQUEST)
            except Exception as data_error:
                return Response({
                    'code': 400,
                    'message': f'请求数据格式错误: {str(data_error)}。请确保提交的是有效的JSON格式数据，属性名必须使用双引号。',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
                
            user = request.user
            allowed_fields = ['email', 'name', 'department', 'group']
            updated_fields = []
            
            for field in allowed_fields:
                if field in request.data:
                    # 检查name字段是否重名
                    if field == 'name' and request.data['name'] != user.name:
                        # 检查是否有其他用户使用相同name
                        if User.objects.filter(name=request.data['name']).exclude(id=user.id).exists():
                            return Response({
                                'code': 400,
                                'message': '用户名称已存在',
                                'data': None
                            }, status=status.HTTP_400_BAD_REQUEST)
                    
                    setattr(user, field, request.data[field])
                    updated_fields.append(field)
            
            if updated_fields:
                try:
                    user.save()
                    return Response({
                        'code': 200,
                        'message': f'用户信息更新成功，已更新字段: {", ".join(updated_fields)}',
                        'data': {
                            'id': str(user.id),
                            'username': user.username,
                            'email': user.email,
                            'name': user.name,
                            'role': user.role,
                            'department': user.department,
                            'group': user.group,
                        }
                    })
                except Exception as save_error:
                    logger.error(f"保存用户数据失败: {str(save_error)}")
                    return Response({
                        'code': 500,
                        'message': f'更新用户信息失败: {str(save_error)}',
                        'data': None
                    }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)
            else:
                return Response({
                    'code': 400,
                    'message': '没有提供任何可更新的字段',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
        else:
            return Response({
                'code': 405,
                'message': f'不支持的请求方法: {request.method}',
                'data': None
            }, status=status.HTTP_405_METHOD_NOT_ALLOWED)
    except Exception as e:
        logger.error(f"处理用户信息请求失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            'code': 500,
            'message': f'处理请求失败: {str(e)}',
            'data': None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@csrf_exempt
@api_view(['POST'])
@permission_classes([IsAuthenticated])
def change_password(request):
    """修改密码"""
    try:
        old_password = request.data.get('old_password')
        new_password = request.data.get('new_password')

        # 验证参数
        if not old_password or not new_password:
            return Response({
                "code": 400,
                "message": "请提供旧密码和新密码",
                "data": None
            }, status=status.HTTP_400_BAD_REQUEST)

        # 验证旧密码
        user = request.user
        if not user.check_password(old_password):
            return Response({
                "code": 400,
                "message": "旧密码错误",
                "data": None
            }, status=status.HTTP_400_BAD_REQUEST)

        # 验证新密码长度
        if len(new_password) < 8:
            return Response({
                "code": 400,
                "message": "新密码长度必须至少为8位",
                "data": None
            }, status=status.HTTP_400_BAD_REQUEST)

        # 修改密码
        user.set_password(new_password)
        user.save()

        # 更新token
        delete_token(user)
        token = generate_token(user)

        return Response({
            "code": 200,
            "message": "密码修改成功",
            "data": {
                "token": token
            }
        })

    except Exception as e:
        logger.error(f"密码修改失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            "code": 500,
            "message": f"密码修改失败: {str(e)}",
            "data": None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@api_view(['GET'])
@permission_classes([IsAuthenticated])
def user_detail(request, pk):
    """获取用户详情"""
    try:
        # 使用通用UUID验证工具函数
        uuid_obj, error_response = validate_uuid_param(pk)
        if error_response:
            return error_response
        
        user = get_object_or_404(User, pk=uuid_obj)
        
        return Response({
            "code": 200,
            "message": "获取用户信息成功",
            "data": format_user_response(user)
        })
    except Exception as e:
        logger.error(f"获取用户信息失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            "code": 500,
            "message": f"获取用户信息失败: {str(e)}",
            "data": None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@api_view(['PUT'])
@permission_classes([IsAuthenticated])
def user_update(request, pk):
    """
    更新用户信息
    - 管理员可以更新任何用户
    - 普通用户只能更新自己的信息
    """
    try:
        try:
            if not request.data:
                return Response({
                    'code': 400,
                    'message': '请求数据为空或格式错误',
                    'data': None
                }, status=status.HTTP_400_BAD_REQUEST)
        except Exception as data_error:
            return Response({
                'code': 400,
                'message': f'请求数据格式错误: {str(data_error)}。请确保提交的是有效的JSON格式数据，属性名必须使用双引号。',
                'data': None
            }, status=status.HTTP_400_BAD_REQUEST)
        
        # 使用通用UUID验证工具函数
        uuid_obj, error_response = validate_uuid_param(pk)
        if error_response:
            return error_response
            
        try:
            user = User.objects.get(pk=uuid_obj)
        except User.DoesNotExist:
            return Response({
                'code': 404,
                'message': '用户不存在',
                'data': None
            }, status=status.HTTP_404_NOT_FOUND)
        
        # 验证权限：用户只能修改自己的信息，管理员可以修改任何人
        is_admin = request.user.is_staff or request.user.role == 'admin'
        is_self_update = str(request.user.id) == str(user.id)
        
        if not (is_admin or is_self_update):
            return Response({
                'code': 403,
                'message': '权限不足，您只能修改自己的信息',
                'data': None
            }, status=status.HTTP_403_FORBIDDEN)
        
        # 根据用户权限决定可以修改的字段
        if is_admin:
            allowed_fields = ['email', 'role', 'department', 'group', 'is_active', 'name']
        else:
            # 普通用户只能修改部分字段
            allowed_fields = ['email', 'name']
            
        updated_fields = []
        
        for field in allowed_fields:
            if field in request.data:
                setattr(user, field, request.data[field])
                updated_fields.append(field)
                
        if not updated_fields:
            return Response({
                'code': 400,
                'message': '没有提供任何可更新的字段',
                'data': None
            }, status=status.HTTP_400_BAD_REQUEST)
                
        user.save()
        
        return Response({
            'code': 200,
            'message': '用户信息更新成功',
            'data': format_user_response(user, include_is_active=is_admin)
        })
    except Exception as e:
        logger.error(f"更新用户信息失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            'code': 500,
            'message': f'更新用户信息失败: {str(e)}',
            'data': None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@api_view(['DELETE'])
@permission_classes([IsAdminUser])
def user_delete(request, pk):
    """删除用户"""
    try:
        # 使用通用UUID验证工具函数
        uuid_obj, error_response = validate_uuid_param(pk)
        if error_response:
            return error_response
            
        try:
            user = User.objects.get(pk=uuid_obj)
        except User.DoesNotExist:
            return Response({
                'code': 404,
                'message': '用户不存在',
                'data': None
            }, status=status.HTTP_404_NOT_FOUND)
            
        if user.is_superuser or user.role == 'admin':
            return Response({
                'code': 403,
                'message': '不允许删除管理员账户',
                'data': None
            }, status=status.HTTP_403_FORBIDDEN)
            
        username = user.username
        user.delete()
        
        return Response({
            'code': 200,
            'message': f'用户 {username} 删除成功',
            'data': None
        })
    except Exception as e:
        logger.error(f"删除用户失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            'code': 500,
            'message': f'删除用户失败: {str(e)}',
            'data': None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@csrf_exempt
@api_view(['POST'])
@permission_classes([IsAuthenticated])
def verify_token(request):
    """验证令牌有效性"""
    try:
        return Response({
            "code": 200,
            "message": "令牌有效",
            "data": {
                "is_valid": True,
                "user": format_user_response(request.user)
            }
        })
    except Exception as e:
        logger.error(f"验证令牌失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            "code": 500,
            "message": f"验证失败: {str(e)}",
            "data": None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

@api_view(['GET'])
@permission_classes([IsAuthenticated])
def user_list(request):
    """获取用户列表"""
    try:
        page = int(request.query_params.get('page', 1))
        page_size = int(request.query_params.get('page_size', 20))
        keyword = request.query_params.get('keyword', '')
        
        user = request.user
        base_query = User.objects.all()
        
        if user.role == 'admin':
            users_query = base_query
        elif user.role == 'leader':
            users_query = base_query.filter(department=user.department)
        else:
            users_query = base_query.filter(id=user.id)
        
        if keyword:
            users_query = users_query.filter(
                Q(username__icontains=keyword) | 
                Q(email__icontains=keyword) | 
                Q(name__icontains=keyword) |
                Q(department__icontains=keyword)
            )
        
        total = users_query.count()
        start = (page - 1) * page_size
        end = start + page_size
        users = users_query[start:end]
        
        user_data = []
        for u in users:
            user_info = format_user_response(u, include_is_active=True)
            user_info['date_joined'] = u.date_joined.strftime('%Y-%m-%d %H:%M:%S')
            user_data.append(user_info)
        
        return Response({
            'code': 200,
            'message': '获取用户列表成功',
            'data': {
                'total': total,
                'page': page,
                'page_size': page_size,
                'users': user_data
            }
        })
    
    except ValueError as e:
        return Response({
            'code': 400,
            'message': f'参数错误: {str(e)}',
            'data': None
        }, status=status.HTTP_400_BAD_REQUEST)
        
    except Exception as e:
        logger.error(f"获取用户列表失败: {str(e)}")
        logger.error(traceback.format_exc())
        return Response({
            'code': 500,
            'message': f'获取用户列表失败: {str(e)}',
            'data': None
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)