import * as esbuild from 'esbuild';
import { spawn } from 'node:child_process';
import { existsSync, watch } from 'node:fs';
import { mkdir, rm } from 'node:fs/promises';
import { buildOptions, outdir, writeManifest } from './build.js';

await rm('dist', { recursive: true, force: true });
await mkdir(outdir, { recursive: true });

const ctx = await esbuild.context({
  ...buildOptions({ dev: true }),
  plugins: [
    {
      name: 'manifest',
      setup(build) {
        build.onEnd((result) => result.metafile && writeManifest(result.metafile));
      },
    },
  ],
});
await ctx.watch();

// Restarting the server ourselves instead of node --watch-path: on Node 24 the
// watch-mode parent sometimes crashes on shutdown and leaves the server running.
const args = [...(existsSync('.env') ? ['--env-file=.env'] : []), 'src/server.js'];
let server;

function start() {
  server = spawn(process.execPath, args, { stdio: 'inherit', env: { ...process.env, NODE_ENV: 'development' } });
}

function restart() {
  if (!server || server.exitCode !== null) return start();
  server.once('exit', start);
  server.kill();
}

let timer;
for (const dir of ['src', 'locales']) {
  watch(dir, { recursive: true }, (event, file) => {
    if (file?.endsWith('.njk')) return; // templates are re-read on every request anyway
    clearTimeout(timer);
    timer = setTimeout(() => {
      console.log(`[dev] ${dir}/${file} changed, restarting`);
      restart();
    }, 150);
  });
}

start();

async function stop() {
  await ctx.dispose();
  if (server?.exitCode === null) {
    server.once('exit', () => process.exit(0));
    server.kill();
  } else {
    process.exit(0);
  }
}
process.on('SIGINT', stop);
process.on('SIGTERM', stop);