import fs from 'fs/promises';
import path from 'node:path';
import { require } from '../utilities/require.js';
import { type Plugin } from 'esbuild';
import { basename } from 'node:path';

export const validExtensions = ['.ts', '.js', '.json', '.png', '.jpg', '.jpeg', '.webp'];

//https://github.com/evanw/esbuild/issues/1051
export const imageLoader = {
    name: 'attachment-loader',
    setup: (b) => {
        const filter = new RegExp(`\.${validExtensions.slice(3).join('|')}$`);
        b.onResolve({ filter }, (args) => {
            //if the module is being imported, resolve the path and transform to the js stub
            if (args.importer) {
                const newPath = path
                    .format({ ...path.parse(args.path), base: '', ext: '.js' })
                    .split(path.sep)
                    .join(path.posix.sep);
                return { path: newPath, namespace: 'attachment-loader', external: true };
            }
            // if the file is actually the attachment, resolve the full dir
            return { path: require.resolve(args.path, { paths: [args.resolveDir] }), namespace: 'attachment-loader' };
        });

        b.onLoad({ filter: /.*/, namespace: 'attachment-loader' }, async (args) => {
            const base64 = await fs.readFile(args.path).then((s) => s.toString('base64'));
            return {
                contents: `
                    var __toBuffer = (base64) => Buffer.from(base64, "base64");
                    module.exports = {
                        name: '${basename(args.path)}',
                        attachment: __toBuffer("${base64}") 
                    }`,
            };
        });
    },
} satisfies Plugin;