#!/usr/bin/env node
// Original MIT-licensed launcher. Node built-ins only; never invokes a shell.
import { spawn } from 'node:child_process';
import { randomInt, randomUUID } from 'node:crypto';
import { constants } from 'node:fs';
import * as fs from 'node:fs/promises';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import { generateAssets } from './assets.mjs';

const source = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
const command = process.argv[2];
const excluded = new Set(['scripts', 'tests', '.git']);
const marker = '.last-hearth-launcher-managed';
const TEST_TIMEOUT = 90_000;
const PLAY_TIMEOUT = 8 * 60 * 60 * 1000;

async function exists(filename) {
  try { await fs.access(filename, constants.F_OK); return true; }
  catch (error) { if (error.code === 'ENOENT') return false; throw error; }
}

// copyFile avoids fs.cp's realpath failures on Windows SMB shares. Refuse
// symlinks/junctions rather than following them out of the selected source.
async function copyTree(from, to, skip = new Set()) {
  const stat = await fs.lstat(from);
  if (stat.isSymbolicLink()) throw new Error(`Refusing symbolic link: ${from}`);
  if (stat.isDirectory()) {
    await fs.mkdir(to, { recursive: true });
    for (const entry of await fs.readdir(from)) {
      if (!skip.has(entry)) await copyTree(path.join(from, entry), path.join(to, entry), skip);
    }
  } else if (stat.isFile()) {
    await fs.copyFile(from, to);
  } else {
    throw new Error(`Not a regular file or directory: ${from}`);
  }
}

async function luaFiles(directory, prefix = '') {
  const result = [];
  for (const entry of await fs.readdir(directory, { withFileTypes: true })) {
    if (entry.isSymbolicLink()) throw new Error(`Refusing symbolic link: ${entry.name}`);
    if (entry.name === '.git' || entry.name === 'scripts') continue;
    const relative = prefix + entry.name;
    if (entry.isDirectory()) result.push(...await luaFiles(path.join(directory, entry.name), relative + '/'));
    else if (entry.isFile() && entry.name.endsWith('.lua')) result.push(relative);
  }
  return result.sort();
}

function coordinates() {
  const latitude = process.env.HEARTH_LATITUDE;
  const longitude = process.env.HEARTH_LONGITUDE;
  if (latitude === undefined && longitude === undefined) return [];
  if (latitude === undefined || longitude === undefined) {
    throw new Error('Provide both HEARTH_LATITUDE and HEARTH_LONGITUDE, or neither.');
  }
  const parse = (value, limit, name) => {
    if (!/^[+-]?(?:\d+(?:\.\d*)?|\.\d+)$/.test(value)) throw new Error(`Invalid ${name}.`);
    const number = Number(value);
    if (!Number.isFinite(number) || Math.abs(number) > limit) throw new Error(`${name} out of range.`);
    return number;
  };
  return [
    `hearth_latitude = ${parse(latitude, 90, 'latitude')}`,
    `hearth_longitude = ${parse(longitude, 180, 'longitude')}`,
  ];
}

function run(executable, args, cwd, timeout, successMarker) {
  return new Promise((resolve, reject) => {
    const child = spawn(executable, args, {
      cwd, shell: false, windowsHide: command !== 'play', stdio: ['ignore', 'pipe', 'pipe'],
    });
    let tail = '', timedOut = false, interrupted = false;
    const capture = stream => {
      stream.setEncoding('utf8');
      stream.on('data', text => {
        // Bound memory even if the engine emits excessive diagnostics.
        tail = (tail + text).slice(-1024 * 1024);
        process.stdout.write(text);
      });
    };
    capture(child.stdout);
    capture(child.stderr);
    const timer = setTimeout(() => { timedOut = true; child.kill('SIGKILL'); }, timeout);
    const interrupt = () => { interrupted = true; child.kill('SIGKILL'); };
    process.once('SIGINT', interrupt);
    process.once('SIGTERM', interrupt);
    const cleanup = () => {
      clearTimeout(timer);
      process.removeListener('SIGINT', interrupt);
      process.removeListener('SIGTERM', interrupt);
    };
    child.once('error', error => { cleanup(); reject(error); });
    child.once('close', (code, signal) => {
      cleanup();
      if (timedOut) reject(new Error(`Process exceeded ${timeout / 1000}s timeout.`));
      else if (interrupted) reject(new Error('Interrupted; child process stopped.'));
      else if (code !== 0) reject(new Error(`Process failed (exit ${code}, signal ${signal || 'none'}).`));
      else if (successMarker && !tail.includes(successMarker)) reject(new Error('Engine exited without the required success marker.'));
      else resolve();
    });
  });
}

async function stageGame(engine) {
  for (const required of ['game.conf', 'mods/hearth/init.lua', 'mods/hearth/model.lua', 'mods/hearth/runtime.lua', 'mods/hearth/content.lua']) {
    if (!await exists(path.join(source, required))) throw new Error(`Game is incomplete: missing ${required}.`);
  }
  const games = path.join(engine, 'games');
  await fs.mkdir(games, { recursive: true });
  const destination = path.join(games, 'last_hearth');
  if (await exists(destination)) {
    if ((await fs.lstat(destination)).isSymbolicLink() || !await exists(path.join(destination, marker))) {
      throw new Error(`Refusing to overwrite an unmanaged game: ${destination}`);
    }
  }
  const stage = await fs.mkdtemp(path.join(games, '.last-hearth-stage-'));
  const backup = path.join(games, `.last-hearth-backup-${randomUUID()}`);
  let backedUp = false;
  try {
    await copyTree(source, stage, excluded);
    await generateAssets(stage, source);
    await fs.writeFile(path.join(stage, marker), 'Managed copy; edit the repository, not this directory.\n');
    if (await exists(destination)) { await fs.rename(destination, backup); backedUp = true; }
    try { await fs.rename(stage, destination); }
    catch (error) { if (backedUp) await fs.rename(backup, destination); throw error; }
    if (backedUp) await fs.rm(backup, { recursive: true, force: true });
  } finally {
    await fs.rm(stage, { recursive: true, force: true });
  }
}

async function writeWorld(world, config, location, extra = []) {
  await fs.mkdir(world, { recursive: true });
  const worldFile = path.join(world, 'world.mt');
  if (!await exists(worldFile)) {
    await fs.writeFile(worldFile, [
      'gameid = last_hearth', 'backend = sqlite3', 'player_backend = sqlite3',
      'auth_backend = sqlite3', 'mod_storage_backend = sqlite3', 'load_mod_hearth = true', '',
    ].join('\n'), { flag: 'wx' });
  }
  await fs.writeFile(config, [
    'enable_damage = true', 'enable_pvp = false', 'creative_mode = false',
    'bind_address = 127.0.0.1', 'server_announce = false', 'enable_ipv6 = false',
    'time_speed = 0', 'movement_speed_walk = 4', 'movement_speed_fast = 6',
    'movement_speed_jump = 6.5', 'secure.enable_security = true',
    'mg_name = v7', 'fixed_map_seed = 731104',
    ...location, ...extra, '',
  ].join('\n'), { mode: 0o600 });
}

async function engineTest(mode, runtime, engine, executable, location) {
  const temporary = await fs.mkdtemp(path.join(runtime, `${mode}-`));
  try {
    const world = path.join(temporary, 'world');
    const config = path.join(temporary, 'minetest.conf');
    const token = randomUUID();
    const mod = path.join(world, 'worldmods', 'hearth_smoke');
    await fs.mkdir(mod, { recursive: true });
    await fs.copyFile(path.join(source, 'tests', 'engine_smoke.lua'), path.join(mod, 'init.lua'));
    await fs.writeFile(path.join(mod, 'mod.conf'), 'name = hearth_smoke\ndepends = hearth\n');
    // Compile standalone tests, never execute their mocked core in the live engine.
    const syntax = path.join(mod, 'syntax');
    await fs.mkdir(syntax);
    const files = await luaFiles(source);
    const names = [];
    for (let index = 0; index < files.length; index++) {
      const name = `${index}.lua`;
      await fs.copyFile(path.join(source, files[index]), path.join(syntax, name));
      names.push(`{file = ${JSON.stringify(name)}, label = ${JSON.stringify(files[index])}}`);
    }
    await fs.writeFile(path.join(mod, 'syntax_manifest.lua'), `return {${names.join(',\n')}}\n`);
    // Explicit synthetic fixture only; real play never defaults to a location.
    const testLocation = location.length ? location : ['hearth_latitude = 45', 'hearth_longitude = 0'];
    await writeWorld(world, config, testLocation, [
      'load_mod_hearth_smoke = true', `hearth_launcher_mode = ${mode}`,
      `hearth_smoke_token = ${token}`, 'max_users = 0',
    ]);
    await run(executable, [
      '--server', '--world', world, '--gameid', 'last_hearth', '--config', config,
      '--port', String(randomInt(49152, 65536)), '--logfile', path.join(temporary, 'engine.log'),
    ], engine, TEST_TIMEOUT, `LAST_HEARTH_${mode.toUpperCase()}_PASS ${token}`);
  } finally {
    await fs.rm(temporary, { recursive: true, force: true });
  }
}

async function standaloneTests(runtime) {
  const candidates = process.env.HEARTH_LUA
    ? [process.env.HEARTH_LUA]
    : ['luajit.exe', 'lua.exe', 'bin/luajit.exe', 'bin/lua.exe'].map(name => path.join(runtime, name));
  let lua;
  for (const candidate of candidates) {
    if (!path.isAbsolute(candidate) || path.extname(candidate).toLowerCase() !== '.exe') {
      throw new Error('HEARTH_LUA must be an absolute path to a local Lua executable (.exe).');
    }
    if (await exists(candidate)) { lua = candidate; break; }
  }
  if (!lua) throw new Error('Standalone Lua unavailable: engine checks passed, but unit tests were NOT run. Install Lua 5.1+/LuaJIT locally and set HEARTH_LUA to its absolute executable path.');
  const specs = (await fs.readdir(path.join(source, 'tests'))).filter(name => name.endsWith('_spec.lua')).sort();
  if (!specs.includes('content_spec.lua')) throw new Error('Missing content_spec.lua; refusing an empty test suite.');
  for (const spec of specs) {
    const module = spec.replace(/_spec\.lua$/, '.lua');
    const modulePath = path.join(source, 'mods', 'hearth', module);
    if (!await exists(modulePath)) throw new Error(`Cannot determine module for ${spec}.`);
    await run(lua, [path.join(source, 'tests', spec), modulePath], source, 30_000);
  }
}

async function main() {
  if (!['check', 'smoke', 'play', 'test'].includes(command) || process.argv.length !== 3) {
    throw new Error('Usage: node scripts/run.mjs <check|smoke|play|test>');
  }
  if (process.platform !== 'win32' || !process.env.LOCALAPPDATA || !path.isAbsolute(process.env.LOCALAPPDATA)) {
    throw new Error('This launcher requires Windows and an absolute LOCALAPPDATA path.');
  }
  const location = coordinates();
  const runtime = path.join(process.env.LOCALAPPDATA, 'last-hearth-runtime');
  const engine = path.join(runtime, 'luanti-5.18.0-win64');
  const executable = path.join(engine, 'bin', 'luanti.exe');
  if (!await exists(executable)) throw new Error(`Official Luanti 5.18.0 runtime not found: ${executable}`);
  const lockPath = path.join(runtime, 'launcher.lock');
  let lock;
  try { lock = await fs.open(lockPath, 'wx', 0o600); }
  catch (error) {
    if (error.code === 'EEXIST') throw new Error('Another launcher may be active. If it crashed, close its engine before removing LOCALAPPDATA/last-hearth-runtime/launcher.lock.');
    throw error;
  }
  try {
    await lock.writeFile(`${process.pid}\n`);
    await stageGame(engine);
    if (command === 'play') {
      const world = path.join(runtime, 'worlds', 'last_hearth');
      const config = path.join(runtime, 'last-hearth-play.conf');
      await writeWorld(world, config, location);
      await run(executable, [
        '--go', '--world', world, '--gameid', 'last_hearth', '--config', config,
        '--port', String(randomInt(49152, 65536)), '--logfile', path.join(runtime, 'last-hearth-play.log'),
      ], engine, PLAY_TIMEOUT);
    } else if (command === 'test') {
      await engineTest('check', runtime, engine, executable, location);
      await engineTest('smoke', runtime, engine, executable, location);
      if (process.env.HEARTH_LUA) await standaloneTests(runtime);
      console.log('LAST_HEARTH_TEST_PASS: real-engine integration and isolated model/content suites completed.');
    } else {
      await engineTest(command, runtime, engine, executable, location);
    }
  } finally {
    await lock.close();
    await fs.unlink(lockPath);
  }
}

main().catch(error => { console.error(`Last Hearth: ${error.message}`); process.exitCode = 1; });