/**
 * Station-variant-spread test (dev tool, run with Node — no browser):
 *
 *   node dev/station-frames.test.mjs
 *
 * Asserts the galaxy-wide deep-space-station variant pass
 * (js/galaxy/StationFrames.js, wired in js/galaxy/Galaxy.js,
 * data/stations.json → variants):
 *   - every deep-space station carries a sheet frame inside the variant
 *     pool (settlement.stationFrame, stamped by the content generator);
 *   - the pass beats a naive random pick: the variant collision rate
 *     among each station's 8-nearest stars is LOWER than the same metric
 *     for an independent random-per-station assignment;
 *   - determinism: same seed ⇒ identical variant map, different seed ⇒
 *     different assignment (spot check);
 *   - lazy === eager: the stamped settlement frames equal a fresh
 *     galaxy's pass output.
 */

process.env.NODE_ENV = 'dev';

import { pathToFileURL } from 'node:url';
import { fileURLToPath } from 'node:url';
import { dirname, join } from 'node:path';

const __dirname = dirname(fileURLToPath(import.meta.url));

const { config } = await import(pathToFileURL(join(__dirname, '../js/config/Config.js')).href);
const fs = await import('node:fs');
const dataDir = join(__dirname, '../data');
const configData = {};
for (const f of fs.readdirSync(dataDir)) {
  if (!f.endsWith('.json') || f === 'manifest.json') continue;
  configData[f.replace(/\.json$/i, '')] = JSON.parse(fs.readFileSync(join(dataDir, f), 'utf8'));
}
config.init(configData);

const { Galaxy } = await import(pathToFileURL(join(__dirname, '../js/galaxy/Galaxy.js')).href);
const { Rng } = await import(pathToFileURL(join(__dirname, '../js/utils/Rng.js')).href);

let failures = 0;
const check = (label, cond, extra = '') => {
  console.log(`${cond ? '✔' : '✘ FAIL'}  ${label}${cond ? '' : ' — ' + extra}`);
  if (!cond) failures++;
};

const SEED = 'station-frames-test-seed';
const g = Galaxy.create(SEED);
const POOL = Math.max(1, Math.floor(g.params.neighbors ?? 8));
const POOLV = (config.get('stations.variants') ?? []).filter((f) => Number.isInteger(f) && f >= 0);
check('data/stations.json → variants is a non-empty integer pool', POOLV.length >= 1, JSON.stringify(config.get('stations.variants')));

// The station-bearing systems and their stamped frame (via content).
const stations = new Map(); // id → { rec, frame, name }
for (const rec of g.records) {
  const c = g.ensureContent(rec.id);
  for (const s of c.settlements) {
    if (s.kind === 'deepSpaceStation') {
      stations.set(rec.id, { rec, frame: s.stationFrame, name: s.name });
    }
  }
}
console.log(`  (galaxy: ${g.records.length} systems, ${stations.size} deep-space stations, pool [${POOLV}])`);

// ----------------------------------------------------------------------
// 1. Frames are present and in-pool
// ----------------------------------------------------------------------
{
  let inPool = true;
  let why = '';
  for (const [id, st] of stations) {
    if (typeof st.frame !== 'number' || !Number.isInteger(st.frame) || !POOLV.includes(st.frame)) {
      inPool = false;
      if (!why) why = `${id}: frame ${st.frame} ∉ [${POOLV}]`;
    }
  }
  check('every deep-space station wears a pool variant (settlement.stationFrame)', inPool, why);
  check('the galaxy pass covers exactly the station-bearing systems',
    stations.size === g.stationFrames.size,
    `${stations.size} settlements vs ${g.stationFrames.size} pass entries`);
}

// ----------------------------------------------------------------------
// 2. The pass beats a naive random assignment
// ----------------------------------------------------------------------
{
  // The pass's variant collision rate: for each station, count its
  // POOL-nearest stars whose station wears the SAME frame (directed).
  const collisionRate = (frameOf) => {
    let coll = 0;
    let checks = 0;
    for (const [id, st] of stations) {
      for (const nb of g.neighborsOf(id, POOL)) {
        checks++;
        const nbFrame = frameOf(nb.id);
        if (nbFrame !== null && nbFrame === st.frame) coll++;
      }
    }
    return { coll, checks, rate: checks === 0 ? 0 : coll / checks };
  };

  const passed = collisionRate((id) => stations.get(id)?.frame ?? null);

  // Naive: independent random pool picks (seeded, per station).
  const naive = new Map();
  for (const id of stations.keys()) {
    const f = POOLV.length === 1
      ? POOLV[0]
      : POOLV[Math.floor(Rng.derive(SEED, 'naive-station', id).next() * POOLV.length)];
    naive.set(id, f);
  }
  const na = collisionRate((id) => naive.get(id) ?? null);

  check(
    `variant collisions vs the ${POOL}-nearest pool: pass ${(passed.rate * 100).toFixed(1)}% < naive ${(na.rate * 100).toFixed(1)}%`,
    passed.rate < na.rate,
    `${passed.coll}/${passed.checks} vs ${na.coll}/${na.checks} (station density sets the floor — most stars carry none)`,
  );

  // The spread should also produce ALL variants across the galaxy
  // (with 3 stations' worth of pool breadth and this many stations,
  // pigeonhole is generous) — the point is variety, not just local spread.
  const used = new Set(stations.size === 0 ? [] : [...stations.values()].map((s) => s.frame));
  check('the galaxy wears more than one station type (the pool shows variety)',
    used.size >= Math.min(2, POOLV.length, stations.size),
    `used [${[...used].sort()}] of pool [${POOLV}]`);
}

// ----------------------------------------------------------------------
// 3. Determinism + lazy === eager
// ----------------------------------------------------------------------
{
  const g2 = Galaxy.create(SEED);
  const same = JSON.stringify([...g.stationFrames.entries()].sort()) ===
    JSON.stringify([...g2.stationFrames.entries()].sort());
  check('same seed ⇒ same station-variant assignment galaxy-wide', same);

  // Content stamp === galaxy pass (the stamping contract).
  let stamped = true;
  let why = '';
  for (const [id, st] of stations) {
    if (g2.stationFrames.get(id) !== st.frame) {
      stamped = false;
      if (!why) why = `${id}: content ${st.frame} vs pass ${g2.stationFrames.get(id)}`;
    }
  }
  check('content settlement frames === the galaxy pass (lazy === eager stamping)', stamped, why);

  const g3 = Galaxy.create('station-frames-OTHER');
  const diff = JSON.stringify([...g.stationFrames.entries()].sort()) !==
    JSON.stringify([...g3.stationFrames.entries()].sort());
  check('different seed ⇒ different assignment (spot check)', diff || g3.records[0].id !== g.records[0].id);
}

console.log(failures === 0 ? '\nAll station-variant tests passed ✔' : `\n${failures} test(s) FAILED ✘`);
process.exit(failures === 0 ? 0 : 1);