chore: migrate to KT financial system

apps/backend/api/finance/media/[id]/download.get.ts

@@ -0,0 +1,46 @@
+import { createReadStream, existsSync, statSync } from 'node:fs';
+import { basename } from 'pathe';
+
+import {
+  getRouterParam,
+  sendStream,
+  setResponseHeader,
+  setResponseStatus,
+} from 'h3';
+
+import { getMediaMessageById } from '~/utils/media-repository';
+import { useResponseError } from '~/utils/response';
+
+export default defineEventHandler((event) => {
+  const idParam = getRouterParam(event, 'id');
+  const id = idParam ? Number.parseInt(idParam, 10) : NaN;
+
+  if (!Number.isInteger(id)) {
+    setResponseStatus(event, 400);
+    return useResponseError('媒体ID不合法', -1);
+  }
+
+  const media = getMediaMessageById(id);
+  if (!media) {
+    setResponseStatus(event, 404);
+    return useResponseError('未找到对应的媒体记录', -1);
+  }
+
+  if (!media.filePath || !existsSync(media.filePath)) {
+    setResponseStatus(event, 404);
+    return useResponseError('媒体文件不存在或已被移除', -1);
+  }
+
+  const fileStats = statSync(media.filePath);
+
+  setResponseHeader(event, 'Content-Type', media.mimeType ?? 'application/octet-stream');
+  setResponseHeader(
+    event,
+    'Content-Disposition',
+    `attachment; filename="${encodeURIComponent(media.fileName ?? basename(media.filePath))}"`,
+  );
+  setResponseHeader(event, 'Content-Length', `${fileStats.size}`);
+
+  return sendStream(event, createReadStream(media.filePath));
+});
+