PronounsPage/server/imageCopy.ts

import { S3 } from '@aws-sdk/client-s3';
import { loadImage, createCanvas } from 'canvas';
import md5 from 'js-md5';
import fetch from 'node-fetch';

import { awsConfig, awsParams } from './aws.ts';

const s3 = new S3(awsConfig);

const convertToPng = async (original: Buffer): Promise<Buffer> => {
    const image = await loadImage(original);
    const canvas = createCanvas(image.width, image.height);
    canvas.getContext('2d').drawImage(image, 0, 0);

    return canvas.toBuffer('image/png');
};

export default async (prefix: string, url: string, ttlDays: number | null = null): Promise<string | null> => {
    if (!url) {
        return null;
    }

    const isSvg = url.toLowerCase().endsWith('.svg');

    const key = `${prefix}/${md5(url)}.${isSvg ? 'svg' : 'png'}`;

    try {
        const metadata = await s3.headObject({ Key: key, ...awsParams });

        if (ttlDays !== null && metadata.LastModified! < new Date(new Date().setDate(new Date().getDate() - ttlDays))) {
            throw 'force refresh';
        }

        return `${process.env.CLOUDFRONT}/${key}`;
    } catch {
        try {
            const originalBuffer = Buffer.from(await (await fetch(url)).arrayBuffer());

            await s3.putObject({
                Key: key,
                Body: isSvg
                    ? originalBuffer
                    : await convertToPng(originalBuffer),
                ContentType: isSvg
                    ? 'image/svg+xml'
                    : 'image/png',
                ACL: 'public-read',
                ...awsParams,
            });

            return `${process.env.CLOUDFRONT}/${key}`;
        } catch (e) {
            return null;
        }
    }
};