import esbuild from 'esbuild';
import svelte from '../utils/svelte-plugin.js';
import del from 'del';
import { promises as fs } from 'fs';
import { dim, green, red, yellow } from 'kleur/colors';
import glob from 'tiny-glob';

/** @type {import('esbuild').BuildOptions} */
const defaultConfig = {
  minify: false,
  format: 'esm',
  platform: 'node',
  // There's an issue with 'node12.20' compiling ESM to CJS
  // so use 'node13.2' instead. V8 support should be similar.
  target: 'node13.2',
  sourcemap: 'inline',
  sourcesContent: false,
};

export default async function build(...args) {
  const config = Object.assign({}, defaultConfig);
  const isDev = args.slice(-1)[0] === 'IS_DEV';
  const patterns = args
    .filter((f) => !!f) // remove empty args
    .map((f) => f.replace(/^'/, '').replace(/'$/, '')); // Needed for Windows: glob strings contain surrounding string chars??? remove these
  let entryPoints = [].concat(...(await Promise.all(patterns.map((pattern) => glob(pattern, { filesOnly: true, absolute: true })))));

  const { type = 'module', dependencies = {} } = await fs.readFile('./package.json').then((res) => JSON.parse(res.toString()));
  const format = type === 'module' ? 'esm' : 'cjs';
  const outdir = 'dist';
  await clean(outdir);

  if (!isDev) {
    await esbuild.build({
      ...config,
      bundle: entryPoints.length === 1, // Note: only use `bundle` with a single entrypoint!
      entryPoints,
      outdir,
      format,
      plugins: [svelte({ isDev })],
    });
    return;
  }

  const builder = await esbuild.build({
    ...config,
    watch: {
      onRebuild(error, result) {
        const date = new Date().toISOString();
        if (error || (result && result.errors.length)) {
          console.error(dim(`[${date}] `) + red(error || result.errors.join('\n')));
        } else {
          if (result.warnings.length) {
            console.log(dim(`[${date}] `) + yellow('⚠ updated with warnings:\n' + result.warnings.join('\n')));
          }
          console.log(dim(`[${date}] `) + green('✔ updated'));
        }
      },
    },
    entryPoints,
    outdir,
    format,
    plugins: [svelte({ isDev })],
  });

  process.on('beforeExit', () => {
    builder.stop && builder.stop();
  });
}

async function clean(outdir) {
  return del([`${outdir}/**`, `!${outdir}/**/*.d.ts`]);
}