from rest_framework.decorators import api_view
from rest_framework.response import Response
from rest_framework import status
from .models import LobsterMemory
from .serializers import LobsterMemorySerializer, FileDiffSerializer
from .services import FileScanner, DiffChecker
import json


@api_view(['GET'])
def scan_files(request):
    """
    扫描本地文件
    """
    lobster_id = request.query_params.get('lobster_id', 'daotong')
    scanner = FileScanner()

    files = scanner.scan_directory(lobster_id)

    return Response({
        'success': True,
        'data': files,
        'total': len(files)
    })


@api_view(['GET'])
def get_file_tree(request):
    """
    获取文件树
    """
    lobster_id = request.query_params.get('lobster_id', 'daotong')
    scanner = FileScanner()

    tree = scanner.get_file_tree(lobster_id)

    return Response({
        'success': True,
        'data': tree
    })


@api_view(['GET'])
def check_sync_status(request):
    """
    检查同步状态
    """
    lobster_id = request.query_params.get('lobster_id', 'daotong')

    # 获取本地文件
    scanner = FileScanner()
    local_files = scanner.scan_directory(lobster_id)

    # 获取数据库文件
    db_files = list(LobsterMemory.objects.filter(
        lobster_id=lobster_id
    ).values('file_path', 'hash', 'version', 'updated_at'))

    # 检查同步状态
    checker = DiffChecker()
    sync_status = checker.check_sync_status(local_files, db_files)

    return Response({
        'success': True,
        'data': sync_status
    })


@api_view(['GET'])
def get_file_diff(request):
    """
    获取文件差异
    """
    file_path = request.query_params.get('file_path')
    lobster_id = request.query_params.get('lobster_id', 'daotong')

    if not file_path:
        return Response({
            'success': False,
            'error': 'file_path is required'
        }, status=status.HTTP_400_BAD_REQUEST)

    scanner = FileScanner()

    # 获取本地内容
    try:
        local_content, local_hash = scanner.get_file_content(file_path)
    except FileNotFoundError:
        local_content = None
        local_hash = None

    # 获取数据库内容
    try:
        db_record = LobsterMemory.objects.filter(
            lobster_id=lobster_id,
            file_path=file_path
        ).order_by('-version').first()

        if db_record:
            db_content = db_record.content
            db_hash = db_record.hash
        else:
            db_content = None
            db_hash = None
    except Exception as e:
        return Response({
            'success': False,
            'error': str(e)
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

    # 获取差异
    checker = DiffChecker()
    if local_content and db_content:
        diff = checker.get_file_diff(local_content, db_content)
    else:
        diff = {
            'local_lines': local_content.split('\n') if local_content else [],
            'db_lines': db_content.split('\n') if db_content else [],
            'has_diff': local_content != db_content
        }

    # 确定状态
    if local_hash == db_hash:
        status = 'consistent'
    elif local_hash and not db_hash:
        status = 'local_newer'
    elif not local_hash and db_hash:
        status = 'db_newer'
    else:
        status = 'conflict'

    return Response({
        'success': True,
        'data': {
            'file_path': file_path,
            'lobster_id': lobster_id,
            'local_content': local_content,
            'db_content': db_content,
            'local_hash': local_hash,
            'db_hash': db_hash,
            'status': status,
            'diff': diff
        }
    })


@api_view(['POST'])
def sync_to_db(request):
    """
    同步到数据库
    """
    lobster_id = request.data.get('lobster_id', 'daotong')
    file_path = request.data.get('file_path')

    if not file_path:
        return Response({
            'success': False,
            'error': 'file_path is required'
        }, status=status.HTTP_400_BAD_REQUEST)

    scanner = FileScanner()

    try:
        # 读取本地文件
        content, file_hash = scanner.get_file_content(file_path)

        # 查找现有记录
        existing = LobsterMemory.objects.filter(
            lobster_id=lobster_id,
            file_path=file_path
        ).order_by('-version').first()

        if existing:
            # 创建新版本
            new_version = existing.version + 1
        else:
            new_version = 1

        # 创建新记录
        record = LobsterMemory.objects.create(
            lobster_id=lobster_id,
            file_path=file_path,
            content=content,
            hash=file_hash,
            status='consistent',
            version=new_version,
        )

        return Response({
            'success': True,
            'message': '已同步到数据库',
            'data': LobsterMemorySerializer(record).data
        })

    except Exception as e:
        return Response({
            'success': False,
            'error': str(e)
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)


@api_view(['POST'])
def sync_to_local(request):
    """
    同步到本地
    """
    lobster_id = request.data.get('lobster_id', 'daotong')
    file_path = request.data.get('file_path')

    if not file_path:
        return Response({
            'success': False,
            'error': 'file_path is required'
        }, status=status.HTTP_400_BAD_REQUEST)

    scanner = FileScanner()

    try:
        # 从数据库获取最新版本
        db_record = LobsterMemory.objects.filter(
            lobster_id=lobster_id,
            file_path=file_path
        ).order_by('-version').first()

        if not db_record:
            return Response({
                'success': False,
                'error': 'File not found in database'
            }, status=status.HTTP_404_NOT_FOUND)

        # 写入本地文件
        scanner.write_file(file_path, db_record.content)

        return Response({
            'success': True,
            'message': '已同步到本地',
            'data': LobsterMemorySerializer(db_record).data
        })

    except Exception as e:
        return Response({
            'success': False,
            'error': str(e)
        }, status=status.HTTP_500_INTERNAL_SERVER_ERROR)


@api_view(['GET'])
def get_versions(request):
    """
    获取文件的所有版本
    """
    file_path = request.query_params.get('file_path')
    lobster_id = request.query_params.get('lobster_id', 'daotong')

    if not file_path:
        return Response({
            'success': False,
            'error': 'file_path is required'
        }, status=status.HTTP_400_BAD_REQUEST)

    versions = LobsterMemory.objects.filter(
        lobster_id=lobster_id,
        file_path=file_path
    ).order_by('-version')

    return Response({
        'success': True,
        'data': LobsterMemorySerializer(versions, many=True).data
    })


@api_view(['GET'])
def get_stats(request):
    """
    获取统计信息
    """
    lobster_id = request.query_params.get('lobster_id', 'daotong')

    total_files = LobsterMemory.objects.filter(lobster_id=lobster_id).count()

    status_counts = {}
    for status_choice, _ in LobsterMemory.STATUS_CHOICES:
        count = LobsterMemory.objects.filter(
            lobster_id=lobster_id,
            status=status_choice
        ).count()
        status_counts[status_choice] = count

    # 获取总大小
    from django.db.models import Sum
    total_size = LobsterMemory.objects.filter(
        lobster_id=lobster_id
    ).aggregate(total=Sum('size'))['total'] or 0

    return Response({
        'success': True,
        'data': {
            'total_files': total_files,
            'status_counts': status_counts,
            'total_size': total_size,
            'total_size_mb': round(total_size / 1024 / 1024, 2)
        }
    })