import { loadImage, createCanvas } from 'canvas';

import { newDate, sha256 } from '#shared/helpers.ts';
import { s3, s3BucketParams } from '~~/server/cloudServices.ts';

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().replace(/\?.*$/, '').endsWith('.svg') || url.startsWith('data:image/svg+xml');

    const key = `${prefix}/${await sha256(url)}.${isSvg ? 'svg' : 'png'}`;

    try {
        const metadata = await s3.headObject({ Key: key, ...s3BucketParams });

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

        return `${process.env.NUXT_PUBLIC_CLOUDFRONT}/${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',
                ...s3BucketParams,
            });

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