import os
import uuid
from pathlib import Path

from django.conf import settings
from django.views.static import serve as static_serve
from rest_framework.decorators import api_view, permission_classes, parser_classes
from rest_framework.permissions import IsAuthenticated
from rest_framework.parsers import MultiPartParser
from rest_framework.response import Response
from rest_framework import status


H5_DIST_ROOT = Path(settings.BASE_DIR).parent / 'frontend-h5' / 'dist'


def serve_h5(request, path=''):
    """
    H5 SPA 静态资源 + history 路由回退。
    - /m/  或 /m/<route>（无扩展名/不存在的路径）→ 返回 dist/index.html
    - /m/assets/xxx.js, /m/img/xxx.jpg 等真实存在的文件 → 直出
    """
    if path:
        candidate = H5_DIST_ROOT / path
        if candidate.is_file():
            return static_serve(request, path, document_root=str(H5_DIST_ROOT))
    return static_serve(request, 'index.html', document_root=str(H5_DIST_ROOT))


ALLOWED_IMAGE_TYPES = {
    'image/jpeg', 'image/png', 'image/gif', 'image/webp', 'image/bmp',
}

MAX_FILE_SIZE = 10 * 1024 * 1024  # 10MB


@api_view(['POST'])
@permission_classes([IsAuthenticated])
@parser_classes([MultiPartParser])
def upload_image(request):
    file = request.FILES.get('file')
    if not file:
        return Response({'detail': '未提供文件'}, status=status.HTTP_400_BAD_REQUEST)

    if file.content_type not in ALLOWED_IMAGE_TYPES:
        return Response(
            {'detail': '仅支持 JPG/PNG/GIF/WEBP/BMP 格式的图片'},
            status=status.HTTP_400_BAD_REQUEST,
        )

    if file.size > MAX_FILE_SIZE:
        return Response(
            {'detail': '文件大小不能超过 10MB'},
            status=status.HTTP_400_BAD_REQUEST,
        )

    ext = os.path.splitext(file.name)[1].lower()
    filename = f"{uuid.uuid4().hex}{ext}"
    relative_path = f"uploads/{filename}"

    full_path = os.path.join(settings.MEDIA_ROOT, relative_path)
    os.makedirs(os.path.dirname(full_path), exist_ok=True)

    with open(full_path, 'wb+') as dest:
        for chunk in file.chunks():
            dest.write(chunk)

    url = request.build_absolute_uri(f"/{settings.MEDIA_URL}{relative_path}")

    return Response({'url': url, 'path': relative_path})