파일 다운로드 임시 구현

src/routes/(fullscreen)/file/[id]/+page.svelte

@@ -0,0 +1,42 @@
+<script lang="ts">
+  import FileSaver from "file-saver";
+  import { TopBar } from "$lib/components";
+  import { masterKeyStore } from "$lib/stores";
+  import { decryptFileMetadata, requestFileDownload } from "./service";
+
+  let { data } = $props();
+
+  let metadata = $state<Awaited<ReturnType<typeof decryptFileMetadata>> | undefined>();
+
+  $effect(() => {
+    if ($masterKeyStore) {
+      decryptFileMetadata(data.metadata, $masterKeyStore.get(data.metadata.mekVersion)!.key).then(
+        async (_metadata) => {
+          metadata = _metadata;
+
+          const file = await requestFileDownload(
+            data.id,
+            data.metadata.contentIv,
+            _metadata.dataKey,
+          );
+
+          // TODO: Preview
+
+          const blob = new Blob([file]);
+
+          FileSaver.saveAs(blob, metadata.name);
+        },
+      );
+    }
+  });
+</script>
+
+<svelte:head>
+  <title>파일</title>
+</svelte:head>
+
+{#if metadata}
+  <TopBar title={metadata.name} />
+{:else}
+  <TopBar />
+{/if}

src/routes/(fullscreen)/file/[id]/+page.ts

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+import { error } from "@sveltejs/kit";
+import { z } from "zod";
+import { callGetApi } from "$lib/hooks";
+import type { FileInfoResponse } from "$lib/server/schemas";
+import type { PageLoad } from "./$types";
+
+export const load: PageLoad = async ({ params, fetch }) => {
+  const zodRes = z
+    .object({
+      id: z.coerce.number().int().positive(),
+    })
+    .safeParse(params);
+  if (!zodRes.success) error(404, "Not found");
+  const { id } = zodRes.data;
+
+  const res = await callGetApi(`/api/file/${id}`, fetch);
+  if (!res.ok) error(404, "Not found");
+
+  const fileInfo: FileInfoResponse = await res.json();
+  return {
+    id,
+    metadata: fileInfo,
+  };
+};

src/routes/(fullscreen)/file/[id]/service.ts

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+import { decryptData } from "$lib/modules/crypto";
+
+export { decryptFileMetadata } from "$lib/services/file";
+
+export const requestFileDownload = (
+  fileId: number,
+  fileEncryptedIv: string,
+  dataKey: CryptoKey,
+) => {
+  return new Promise<ArrayBuffer>((resolve, reject) => {
+    const xhr = new XMLHttpRequest();
+    xhr.responseType = "arraybuffer";
+
+    xhr.addEventListener("load", async () => {
+      if (xhr.status !== 200) {
+        reject(new Error("Failed to download file"));
+        return;
+      }
+
+      const fileDecrypted = await decryptData(
+        xhr.response as ArrayBuffer,
+        fileEncryptedIv,
+        dataKey,
+      );
+      resolve(fileDecrypted);
+    });
+
+    // TODO: Progress, ...
+
+    xhr.open("GET", `/api/file/${fileId}/download`);
+    xhr.send();
+  });
+};