const path = require('path');
const os = require('os');
const fetch = require('node-fetch');

const {
  GITEA_TOKEN,
  REPO_URL = 'https://repo.cloud.thinklink.ai/thinklink/kitchen-agent.git',
  REPO_BRANCH = 'main',
  PM2_APP = 'kitchen-agent'
} = process.env;

const repositoryNormalized = REPO_URL.endsWith('.git') ? REPO_URL : `${REPO_URL}.git`;

const updaterOptions = {
  repository: repositoryNormalized,
  branch: REPO_BRANCH,
  token: GITEA_TOKEN,
  // place updates in OS temp dir to avoid permission/self-copy issues
  tempLocation: path.join(os.tmpdir(), 'kitchen-agent-updates'),
  // only include files that actually exist in the upstream repo; module uses unlinkSync
  ignoreFiles: ['.env'],
  executeOnComplete: process.platform === 'win32'
    ? `IF EXIST package-lock.json (npm ci --omit=dev) ELSE (npm install --omit=dev) & pm2 reload ${PM2_APP}`
    : `[ -f package-lock.json ] && npm ci --omit=dev || npm install --omit=dev; pm2 reload ${PM2_APP}`,
  exitOnComplete: false
};

let updaterInstance = null;

async function getUpdater() {
  if (updaterInstance) { return updaterInstance; }
  const mod = await import('auto-git-update');
  const AutoGitUpdate = mod && mod.default ? mod.default : mod;
  updaterInstance = new AutoGitUpdate(updaterOptions);
  return updaterInstance;
}

async function checkAndUpdate() {
  try {
    const updater = await getUpdater();

    const isGithub = /github\.com/i.test(repositoryNormalized);
    let needsUpdate = false;

    if (!isGithub) {
      // Use Gitea-aware version check to avoid library's GitHub-only path
      const localVersion = (() => {
        try { return require('./package.json').version || null; } catch (_) { return null; }
      })();
      const base = repositoryNormalized.replace(/\.git$/i, '');
      const rawUrl = `${base}/raw/branch/${REPO_BRANCH}/package.json`;

      async function tryFetch(url) {
        const headers = GITEA_TOKEN ? { Authorization: `token ${GITEA_TOKEN}` } : undefined;
        const r = await fetch(url, { headers });
        if (r.ok) return r.json();
        return null;
      }

      let remotePkg = await tryFetch(rawUrl);
      if (!remotePkg && GITEA_TOKEN) {
        remotePkg = (await tryFetch(`${rawUrl}?token=${GITEA_TOKEN}`))
          || (await tryFetch(`${rawUrl}?access_token=${GITEA_TOKEN}`));
      }

      const remoteVersion = remotePkg && remotePkg.version ? String(remotePkg.version) : null;
      if (!remoteVersion) {
        console.error('[auto-update] Unable to read remote version from Gitea raw endpoint');
      } else if (!localVersion || remoteVersion !== String(localVersion)) {
        console.log(`[auto-update] Update available: ${localVersion || 'unknown'} -> ${remoteVersion}`);
        needsUpdate = true;
      }

      if (needsUpdate) {
        await updater.forceUpdate();
      } else {
        console.log('[auto-update] Up to date');
      }
      return;
    }

    // GitHub-based repos: use library's compareVersions, then forceUpdate to avoid double compare
    const res = await updater.compareVersions();
    if (res && res.upToDate === false) {
      await updater.forceUpdate();
    } else {
      console.log('[auto-update] Up to date');
    }
  } catch (err) {
    console.error('[auto-update] failed:', err);
  }
}

module.exports = { checkAndUpdate };