Interface: BijectionStorageWriter

export const prepare = mutation({
  args: { report: v.id("reports") },
  handler: async (ctx, { report }) =>
    await ctx.storage.prepareUpload({
      complete: internal.reports.attach,
      args: { report },
      maxBytes: 10 * 1024 * 1024,
      contentType: "application/pdf",
    }),
});
export const attach = internalMutation({
  args: { file: v.id("_storage"), report: v.id("reports") },
  handler: async (ctx, { file, report }) => {
    await ctx.db.patch(report, { file });
  },
});

const url = await ctx.storage.getUrl(storageId);

const metadata = await ctx.db.system.get("_storage", storageId);
// { _id, _creationTime, sha256, size, contentType? }

// In a mutation, generate the upload URL:
export const generateUploadUrl = mutation({
  args: {},
  returns: v.string(),
  handler: async (ctx) => {
    return await ctx.storage.generateUploadUrl();
  },
});

// On the client, upload the file:
// const uploadUrl = await generateUploadUrl();
// const result = await fetch(uploadUrl, { method: "POST", body: file });
// const { storageId } = await result.json();

await ctx.storage.delete(storageId);