#!/usr/bin/env node
'use strict';

/**
 * Raise, clear or list ProdDash alerts from the command line — for trying a
 * dashboard's channels and the admin colours, or from a script on the
 * machine running ProdDash (anything that can POST JSON can raise one).
 *
 *   node tools/alert.js "Service over by 5:00"              # low, channel 1, 15 s
 *   node tools/alert.js -c 2 -l critical -d 0 "LTC lost"    # held until cleared
 *   node tools/alert.js -c 2 --clear
 *   node tools/alert.js --list
 *
 * Options: -c/--channel 1–6 (default 1), -l/--level low|medium|critical
 * (default low), -d/--duration seconds, 0 to hold until cleared (default the
 * server's 15), --url http://host:port (default http://127.0.0.1:24500, or
 * $PRODDASH_URL), --clear, --list. Node 18+, no dependencies.
 */

const args = process.argv.slice(2);
const opts = { channel: 1, level: 'low', duration: undefined, url: process.env.PRODDASH_URL || 'http://127.0.0.1:24500', clear: false, list: false };
const words = [];
for (let i = 0; i < args.length; i += 1) {
  const a = args[i];
  const next = () => args[++i];
  if (a === '-c' || a === '--channel') opts.channel = Number(next());
  else if (a === '-l' || a === '--level') opts.level = String(next() || '');
  else if (a === '-d' || a === '--duration') opts.duration = Number(next());
  else if (a === '--url') opts.url = String(next() || opts.url);
  else if (a === '--clear') opts.clear = true;
  else if (a === '--list') opts.list = true;
  else if (a === '-h' || a === '--help') {
    console.log('usage: node tools/alert.js [-c 1-6] [-l low|medium|critical] [-d seconds] [--url http://host:port] "text"\n'
      + '       node tools/alert.js -c <n> --clear\n'
      + '       node tools/alert.js --list');
    process.exit(0);
  } else words.push(a);
}
const base = opts.url.replace(/\/+$/, '');

async function call(path, init) {
  const res = await fetch(base + path, init);
  const body = await res.json().catch(() => ({}));
  if (!res.ok) throw new Error(body.error || `HTTP ${res.status}`);
  return body;
}

(async () => {
  if (opts.list) {
    const body = await call('/api/alerts');
    const active = body.active || [];
    console.log(`${active.length} active alert${active.length === 1 ? '' : 's'}; colours:`,
      Object.entries(body.colors || {}).map(([k, v]) => `${k} ${v.join('→')}`).join(', '));
    for (const a of active) {
      console.log(`  channel ${a.channel}  ${a.level.padEnd(8)}  "${a.text}"  from ${a.source}`
        + (a.remainingMs === null ? '  (until cleared)' : `  (${Math.ceil(a.remainingMs / 1000)} s left)`));
    }
    return;
  }
  if (opts.clear) {
    const body = await call(`/api/alerts/${opts.channel}`, { method: 'DELETE' });
    console.log(body.cleared ? `cleared channel ${opts.channel}` : `nothing was on channel ${opts.channel}`);
    return;
  }
  const text = words.join(' ').trim();
  if (!text) {
    console.error('say what happened: node tools/alert.js -c 1 -l critical "LTC lost"');
    process.exit(2);
  }
  const payload = { channel: opts.channel, level: opts.level, text, source: 'cli' };
  if (opts.duration !== undefined) payload.duration = opts.duration;
  const body = await call('/api/alerts', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(payload),
  });
  const a = body.alert;
  console.log(`raised ${a.level} on channel ${a.channel}: "${a.text}"`
    + (a.remainingMs === null ? ' (until cleared)' : ` (${a.duration} s)`));
})().catch((err) => {
  console.error(err.message || String(err));
  process.exit(1);
});