vielle.dev
Discord bot to open dong files
add dong-io.ts from https://github.com/dong-files/web/blob/master/src/dong-io.ts
this will be replaced with a package etc once i get around to extracting it out lol
+120
src/lib/dong-io.ts
+120
src/lib/dong-io.ts
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declare global {
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interface Uint8Array {
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toBase64(): string;
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}
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}
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const blobBytes = async (blob: Blob) => {
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if ("bytes" in blob) return blob.bytes();
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return new Response(blob).arrayBuffer().then((buffer) => {
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const uint = new Uint8Array(buffer);
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return uint;
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});
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};
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export const createDong = async (
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image: File,
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audio: File
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): Promise<Blob | string> => {
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if (
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image.type === "" ||
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!image.type.startsWith("image/") ||
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audio.type === "" ||
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!audio.type.startsWith("audio/")
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)
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return "Mime types invalid";
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return new Blob([
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// version
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(() => {
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const version = new Int8Array(new ArrayBuffer(2));
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version[0] = 0xd0;
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version[1] = 2;
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return version;
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})(),
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// image type
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image.type,
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// 00 padding
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new ArrayBuffer(256 - image.type.length),
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// image size
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(() => {
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const value = new Uint32Array(1);
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value[0] = image.size;
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return value;
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})(),
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// audio type
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audio.type,
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// 00 padding
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new ArrayBuffer(256 - audio.type.length),
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// audio size
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(() => {
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const value = new Uint32Array(1);
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value[0] = audio.size;
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return value;
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})(),
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// image data
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await blobBytes(image),
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// audio data
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await blobBytes(audio),
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]);
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};
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export async function readDong(dongFile: File): Promise<
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| {
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image: { data: Uint8Array; mime: string };
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audio: { data: Uint8Array; mime: string };
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}
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| string
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> {
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// get first 2 bytes and verify
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const version = new Uint8Array(await blobBytes(dongFile.slice(0, 2)));
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if (version[0] !== 0xd0 || version[1] !== 2) return "Invalid file";
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// get next 256 bytes and get mime type
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const imgMimeType: string | undefined = (
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await dongFile.slice(2, 258).text()
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).match(/[a-zA-Z0-9.]+\/[a-zA-Z0-9.]+/gm)?.[0];
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if (!imgMimeType) return "Image mime type parse failed";
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// get next 4 bytes and get image size
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const imgSize = new Uint32Array(
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(await blobBytes(dongFile.slice(258, 262))).buffer
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)[0];
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// get next 256 bytes and get mime type
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const audMimeType: string | undefined = (
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await dongFile.slice(262, 518).text()
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).match(/[a-zA-Z0-9.]+\/[a-zA-Z0-9.]+/gm)?.[0];
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if (!audMimeType) return "Audio mime type parse failed";
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// get next 4 bytes and get image size
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const audSize = new Uint32Array(
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(await blobBytes(dongFile.slice(518, 522))).buffer
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)[0];
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const imageBytes = await blobBytes(dongFile.slice(522, 522 + imgSize));
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const audioBytes = await blobBytes(
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dongFile.slice(522 + imgSize, 522 + imgSize + audSize)
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);
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return {
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image: {
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mime: imgMimeType,
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data: imageBytes,
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},
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audio: {
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mime: audMimeType,
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data: audioBytes,
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},
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};
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}
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export const download = (file: File) => {
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const url = URL.createObjectURL(file);
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const a = document.createElement("a");
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a.href = url;
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a.download = file.name;
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document.body.appendChild(a);
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a.click();
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document.body.removeChild(a);
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URL.revokeObjectURL(url);
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};