feat: 优化图片资源删除管理，生图任务列表管理

server/api/export.py

@@ -10,14 +10,17 @@ from __future__ import annotations
 import io
 import mimetypes
 import re
+import tempfile
 import zipfile
+from collections.abc import Iterator
 
 from fastapi import APIRouter, HTTPException
-from fastapi.responses import StreamingResponse
+from fastapi.responses import Response, StreamingResponse
 from pydantic import BaseModel, Field
 
 from api.proxy import guess_referer
-from services.storage import download_bytes, local_path
+from config import get_settings
+from services.storage import ResourceSizeLimitError, download_bytes, local_path, read_local_bytes
 
 router = APIRouter(prefix="/api", tags=["export"])
 
@@ -39,7 +42,7 @@ class ExportImageItem(BaseModel):
 
 class ExportImagesRequest(BaseModel):
     title: str | None = Field(default=None, description="商品标题，用作 ZIP 顶层文件夹名")
-    images: list[ExportImageItem]
+    images: list[ExportImageItem] = Field(min_length=1)
 
 
 def _clean(name: str) -> str:
@@ -75,47 +78,102 @@ async def _download(url: str) -> tuple[bytes, str]:
     path = local_path(url)
     if path is not None:
         mime = mimetypes.guess_type(path.name)[0] or "image/jpeg"
-        return path.read_bytes(), mime
+        return read_local_bytes(path), mime
     return await download_bytes(url, referer=guess_referer(url))
 
 
+def _stream_file(handle: io.BufferedRandom, chunk_size: int = 64 * 1024) -> Iterator[bytes]:
+    """以固定块流式返回临时 ZIP，响应结束（或中断）后关闭临时文件。"""
+    try:
+        while chunk := handle.read(chunk_size):
+            yield chunk
+    finally:
+        handle.close()
+
+
 @router.post("/export/images")
 async def export_images(req: ExportImagesRequest):
-    if not req.images:
-        raise HTTPException(status_code=400, detail="没有可导出的图片")
+    settings = get_settings()
+    if len(req.images) > settings.export_max_images:
+        raise HTTPException(status_code=413, detail=f"一次最多导出 {settings.export_max_images} 张图片，请分批导出")
 
     root = _clean(req.title) or "采集图片"
-    buf = io.BytesIO()
+    # 小 ZIP 留在内存，大 ZIP 自动滚动到临时磁盘；响应阶段按块传输。
+    archive = tempfile.SpooledTemporaryFile(
+        max_size=settings.export_zip_memory_threshold_bytes,
+        mode="w+b",
+    )
     used: set[str] = set()
+    total_source_bytes = 0
 
-    with zipfile.ZipFile(buf, "w", zipfile.ZIP_DEFLATED) as zf:
-        for img in req.images:
-            try:
-                data, ctype = await _download(img.url)
-            except Exception:  # noqa: BLE001
-                continue  # 单张失败不中断整包
-            if not _is_image(img.url, ctype):
-                continue
+    try:
+        with zipfile.ZipFile(archive, "w", zipfile.ZIP_DEFLATED) as zf:
+            for img in req.images:
+                try:
+                    data, ctype = await _download(img.url)
+                except ResourceSizeLimitError as exc:
+                    raise HTTPException(status_code=413, detail=f"无法导出「{img.key or '图片'}」：{exc}") from exc
+                except Exception:  # noqa: BLE001
+                    continue  # 单张下载失败不中断整包
+                if not _is_image(img.url, ctype):
+                    continue
+                total_source_bytes += len(data)
+                if total_source_bytes > settings.export_zip_max_bytes:
+                    raise HTTPException(
+                        status_code=413,
+                        detail=f"导出图片总大小超过 {settings.export_zip_max_bytes // 1024 // 1024} MB，请减少勾选图片后重试",
+                    )
 
-            ext = _ext(img.url, ctype)
-            base = _clean(img.key) or "image"
-            if img.variantName:
-                base += f"-{_clean(img.variantName)}"
-            filename = f"{base}{ext}"
-            if filename in used:  # 同名加序号防覆盖
-                stem = filename[: -len(ext)]
-                n = 2
-                while f"{stem}-{n}{ext}" in used:
-                    n += 1
-                filename = f"{stem}-{n}{ext}"
-            used.add(filename)
+                ext = _ext(img.url, ctype)
+                base = _clean(img.key) or "image"
+                if img.variantName:
+                    base += f"-{_clean(img.variantName)}"
+                filename = f"{base}{ext}"
+                if filename in used:  # 同名加序号防覆盖
+                    stem = filename[: -len(ext)]
+                    n = 2
+                    while f"{stem}-{n}{ext}" in used:
+                        n += 1
+                    filename = f"{stem}-{n}{ext}"
+                used.add(filename)
 
-            group = _clean(img.groupName) or "图片"
-            zf.writestr(f"{root}/{group}/{filename}", data)
+                group = _clean(img.groupName) or "图片"
+                zf.writestr(f"{root}/{group}/{filename}", data)
+                if archive.tell() > settings.export_zip_max_bytes:
+                    raise HTTPException(
+                        status_code=413,
+                        detail=f"导出 ZIP 超过 {settings.export_zip_max_bytes // 1024 // 1024} MB，请减少勾选图片后重试",
+                    )
+    except Exception:
+        archive.close()
+        raise
 
-    buf.seek(0)
+    archive.seek(0)
     return StreamingResponse(
-        buf,
+        _stream_file(archive),
         media_type="application/zip",
         headers={"Content-Disposition": 'attachment; filename="collect.zip"'},
     )
+
+
+@router.post("/export/image")
+async def export_image(img: ExportImageItem):
+    """代理下载单张图片，兼容源站防盗链与本地媒体路径。"""
+    try:
+        data, ctype = await _download(img.url)
+    except ResourceSizeLimitError as exc:
+        raise HTTPException(status_code=413, detail=f"图片文件过大，无法下载：{exc}") from exc
+    except Exception as exc:  # noqa: BLE001
+        raise HTTPException(status_code=422, detail="图片下载失败") from exc
+    if not _is_image(img.url, ctype):
+        raise HTTPException(status_code=400, detail="该地址不是图片")
+
+    ext = _ext(img.url, ctype)
+    base = _clean(img.key) or "image"
+    if img.variantName:
+        base += f"-{_clean(img.variantName)}"
+    return Response(
+        content=data,
+        media_type=ctype,
+        headers={"Content-Disposition": f'attachment; filename="{base}{ext}"'},
+    )