commit 6d5e9ce7c5018681f4f30cea4873fe42813d46cb · vielle.dev/discord-donger

+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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       };