Add manga extracting

src/lib/util/zip.ts

@@ -0,0 +1,56 @@
+import type { Volume } from "$lib/types";
+import {
+  BlobReader,
+  BlobWriter,
+  TextReader,
+  ZipWriter,
+} from "@zip.js/zip.js";
+
+async function zipVolumes(manga: Volume[]) {
+  const volumeZips = []
+
+  for (const volume of manga) {
+    const files = Object.values(volume.files);
+    const zipWriter = new ZipWriter(new BlobWriter("application/zip"));
+
+    const promises = files.map((file) => {
+      return zipWriter.add(file.name, new BlobReader(file))
+    })
+
+
+    await Promise.all(promises);
+
+
+    volumeZips.push({
+      zipName: volume.volumeName,
+      zipBlob: await zipWriter.close(),
+      mokuroData: JSON.stringify(volume.mokuroData)
+    });
+  }
+
+  return volumeZips;
+}
+
+export async function zipManga(manga: Volume[]) {
+  const volumeZips = await zipVolumes(manga)
+  const zipWriter = new ZipWriter(new BlobWriter("application/zip"));
+
+
+  const promises = volumeZips.map((volumeZip) => {
+    return [
+      zipWriter.add(`${volumeZip.zipName}.mokuro`, new TextReader(volumeZip.mokuroData)),
+      zipWriter.add(`${volumeZip.zipName}.zip`, new BlobReader(volumeZip.zipBlob))
+    ]
+  })
+
+  await Promise.all(promises);
+
+  const zipFileBlob = await zipWriter.close();
+
+  const link = document.createElement('a');
+  link.href = URL.createObjectURL(zipFileBlob);
+  link.download = `${manga[0].mokuroData.title}.zip`;
+  link.click();
+
+  return false
+}