// About me: Writes the missing Steam libraryfolders.vdf into a Wine prefix from
// the Linux side, before Vortex is ever started. Vortex core scans Steam at
// startup and reads C:\Program Files (x86)\Steam\config\libraryfolders.vdf; when
// SteamTinkerLaunch has not created it, the unhandled ENOENT shows up as
// "unrecoverable error" and Vortex dies. Running this once repairs the prefix.
//
// Usage: node scripts/repair-prefix.mjs [--prefix <pfx>] [--force] [--dry-run]
import { existsSync, mkdirSync, readFileSync, readdirSync, realpathSync, writeFileSync } from 'node:fs';
import { homedir } from 'node:os';
import { resolve } from 'node:path';

import { findSteamLibraries, findSteamRoots } from '../src/discovery.ts';
import {
  PREFIX_STEAM_DIR,
  buildShimVdf,
  dedupeByCanonicalPath,
  ensureSteamShim,
} from '../src/steamShim.ts';

const DEFAULT_PREFIX = resolve(homedir(), '.config/steamtinkerlaunch/vortex/compatdata/pfx');

function parseArgs(argv) {
  const args = { prefix: DEFAULT_PREFIX, force: false, dryRun: false };
  for (let i = 0; i < argv.length; i += 1) {
    if (argv[i] === '--prefix') {
      args.prefix = resolve(argv[i + 1] ?? '');
      i += 1;
    } else if (argv[i] === '--force') {
      args.force = true;
    } else if (argv[i] === '--dry-run') {
      args.dryRun = true;
    } else {
      throw new Error(`unknown argument: ${argv[i]}`);
    }
  }
  return args;
}

/**
 * Resolves the paths Vortex would see inside the prefix to real Linux paths:
 * Z: is the Linux root, C: is the prefix's drive_c.
 */
function toRealPath(prefix, winPath) {
  const normalised = winPath.replace(/\\/g, '/');
  if (/^[zZ]:/.test(normalised)) {
    return normalised.slice(2) || '/';
  }
  if (/^[cC]:/.test(normalised)) {
    return resolve(prefix, 'drive_c', normalised.slice(3));
  }
  return normalised;
}

function prefixFileAccess(prefix) {
  return {
    exists: (p) => existsSync(toRealPath(prefix, p)),
    readFile: (p) => readFileSync(toRealPath(prefix, p), 'utf8'),
    readDir: (p) => {
      try {
        return readdirSync(toRealPath(prefix, p));
      } catch {
        return [];
      }
    },
  };
}

const args = parseArgs(process.argv.slice(2));

if (!existsSync(args.prefix)) {
  console.error(`prefix not found: ${args.prefix}`);
  process.exit(1);
}

const files = prefixFileAccess(args.prefix);

// Only the Wine-side (Z:) view is useful here: the shim has to contain paths
// Vortex can open from inside the prefix.
const libraries = dedupeByCanonicalPath(
  [
    ...new Set(
      findSteamRoots(files)
        .filter((root) => root.startsWith('Z:'))
        .flatMap((root) => findSteamLibraries(files, root)),
    ),
  ],
  (candidate) => realpathSync(toRealPath(args.prefix, candidate)),
);

console.log(`prefix:      ${args.prefix}`);
console.log(`steam dir:   ${toRealPath(args.prefix, PREFIX_STEAM_DIR)}`);
console.log(`libraries:   ${libraries.length === 0 ? '(none found)' : ''}`);
for (const library of libraries) {
  console.log(`  ${library}`);
}

if (args.dryRun) {
  console.log('--- shim that would be written ---');
  console.log(buildShimVdf(libraries));
  process.exit(0);
}

const writer = {
  makeDir: (p) => mkdirSync(toRealPath(args.prefix, p), { recursive: true }),
  writeFile: (p, contents) => writeFileSync(toRealPath(args.prefix, p), contents, 'utf8'),
};

const result = ensureSteamShim(files, writer, libraries, { overwrite: args.force });
console.log(`result:      ${result.action} -> ${toRealPath(args.prefix, result.path)}`);

if (result.action === 'skipped') {
  console.error(
    libraries.length === 0
      ? 'no Steam libraries found under /home; pass --prefix for the right prefix or check your Steam install'
      : `no Steam directory at ${toRealPath(args.prefix, PREFIX_STEAM_DIR)}; is this the Vortex prefix?`,
  );
  process.exit(1);
}