scrptly/src/assetUploader.ts

Scrptly is a Video Development Kit (VDK) for programmatically generating AI-powered videos.

import fs from 'fs';
import crypto from 'crypto';
import type Scrptly from './index';

export default class AssetUploader {
	$: Scrptly;
	path: string;
	type: string;

	constructor($: Scrptly, path: string, type: string) {
		this.$ = $;
		this.path = path;
		this.type = type;
	}

	async hashFile(): Promise<string> {
		return new Promise((resolve, reject) => {
			const hash = crypto.createHash('md5');
			const stream = fs.createReadStream(this.path);
			stream.on('error', reject);
			stream.on('data', chunk => {
				hash.update(chunk);
			});

			stream.on('end', () => {
				resolve(hash.digest('base64'));
			});
		});
	}

	async uploadAsset() {
		// Calculate hash of the file
		const { size } = await fs.promises.stat(this.path);
		const hash = await this.hashFile();
		const fileName = this.path.split('/').pop();
		const extension = fileName?.split('.').pop();
		if(!fileName || !extension)
			throw new Error('Invalid file name or extension');
		const prepare = await this.$.apiCall('prepareAsset', {
			method: 'POST',
			body: JSON.stringify({
				fileName,
				hash,
				type: this.type,
				extension,
				size
			}),
		});
		if(prepare.success) {
			if(prepare.found) {
				return {assetId: prepare.assetId, url: prepare.url};
			} else if(prepare.presignedUrl) {
				const fileStream = fs.createReadStream(this.path);
				const res = await fetch(prepare.presignedUrl, {
					method: 'PUT',
					headers: {
						'Content-Type': prepare.contentType,
						'Content-Length': size.toString(),
						'Content-MD5': hash,
					},
					body: fileStream as any,
					// @ts-expect-error
					duplex: 'half'
				});
				if (res.ok) {
					const successUpload = await this.$.apiCall('completeAssetUpload', {
						method: 'POST',
						body: JSON.stringify({
							assetId: prepare.assetId,
							result: 'success',
						}),
					});
					if(successUpload.success) {
						return {assetId: successUpload.assetId, url: successUpload.url};
					} else {
						throw new Error(`Could not complete upload: ${successUpload.error}`);
					}
				} else {
					await this.$.apiCall('completeAssetUpload', {
						method: 'POST',
						body: JSON.stringify({
							assetId: prepare.assetId,
							result: 'error',
						}),
					});
					throw new Error(`Upload failed [${res.status}]\n> ${await res.text()}`);
				}
			} else {
				throw new Error('Invalid response from server');
			}
		} else {
			throw new Error(`Error uploading asset: ${prepare.error}`);
		}
	}
}