'use strict';

const path = require('path');
const { listReleaseAttachmentNames } = require('./github');

/** Legacy launcher.json rows — ignored when merging explicit files. */
const DEPRECATED_SOURCES = new Set(['patch-Z.MPQ', 'Wow-patched.exe']);

function filterExplicitFiles(files) {
  if (!Array.isArray(files)) return [];
  return files
    .filter((e) => e && String(e.source || '').trim())
    .filter((e) => !DEPRECATED_SOURCES.has(String(e.source).trim()))
    .map((e) => ({
      source: String(e.source).trim(),
      dest: String(e.dest || '').trim(),
      backup: e.backup !== false,
      from_release: e.from_release !== false,
    }))
    .filter((e) => e.dest);
}

function manifestLooksUsable(m) {
  return !!(m && m.files && typeof m.files === 'object' && Object.keys(m.files).length > 0);
}

/** Launcher / updater attachments — never copied into the WoW folder. */
function isExcludedFromGameSync(fileName) {
  const n = String(fileName || '');
  const lower = n.toLowerCase();
  if (lower === 'patch-manifest.json') return true;
  if (/^fractured-launcher/i.test(n)) return true;
  if (/\.blockmap$/i.test(n)) return true;
  if (/^latest.*\.ya?ml$/i.test(n) || lower === 'latest.yml') return true;
  if (lower.includes('builder-debug')) return true;
  if (/\.appimage$/i.test(n)) return true;
  return false;
}

function destForReleaseSource(source, cfg) {
  const base = path.basename(String(source || ''));
  if (/\.mpq$/i.test(base)) return `Data/${base}`;
  if (/\.exe$/i.test(base)) return (cfg.launch && cfg.launch.exe) || 'Wow.exe';
  return base;
}

/**
 * Explicit `files` in config wins. Otherwise use patch-manifest keys if present,
 * else discover attachments on the release (excluding launcher artifacts).
 */
async function buildResolvedReleaseFiles(cfg, manifestMaybeNull) {
  const explicit = filterExplicitFiles(cfg.files);
  if (explicit.length) return explicit;

  const manifest = manifestMaybeNull;
  if (manifestLooksUsable(manifest)) {
    const keys = Object.keys(manifest.files).filter((k) => k && !isExcludedFromGameSync(k));
    if (!keys.length) {
      throw new Error('patch-manifest.json has no file entries — add files or attach assets to the release.');
    }
    return keys.map((source) => ({
      source,
      dest: destForReleaseSource(source, cfg),
      backup: true,
      from_release: true,
    }));
  }

  const names = await listReleaseAttachmentNames(cfg);
  const game = names.filter((n) => n && !isExcludedFromGameSync(n));
  if (!game.length) {
    throw new Error(
      'No patch files on this release (after excluding launcher installers). ' +
        'Attach MPQ/exe assets or ship patch-manifest.json listing filenames.'
    );
  }

  const exes = game.filter((n) => /\.exe$/i.test(n));
  const mpqs = game.filter((n) => /\.mpq$/i.test(n));
  const rest = game.filter((n) => !/\.(exe|mpq)$/i.test(n));

  if (exes.length > 1) {
    throw new Error(
      `Release has multiple .exe files (${exes.join(', ')}). ` +
        'Remove extras or publish patch-manifest.json with the exact filenames to install.'
    );
  }

  const out = [];
  for (const n of mpqs) {
    out.push({
      source: n,
      dest: path.posix.join('Data', path.basename(n)),
      backup: true,
      from_release: true,
    });
  }
  if (exes.length === 1) {
    out.push({
      source: exes[0],
      dest: (cfg.launch && cfg.launch.exe) || 'Wow.exe',
      backup: true,
      from_release: true,
    });
  }
  for (const n of rest) {
    out.push({
      source: n,
      dest: path.basename(n),
      backup: true,
      from_release: true,
    });
  }
  return out;
}

module.exports = {
  buildResolvedReleaseFiles,
  filterExplicitFiles,
  isExcludedFromGameSync,
  DEPRECATED_SOURCES,
};