const { execFileSync } = require('child_process');

/**
 * target repo 的 git add/commit/push 封裝（design.md §4：git commit/push 觸發既有
 * Gitea push webhook → ingest workflow；本模組不打任何 ingest HTTP 端點）。
 */
class GitSync {
  constructor(config) {
    this.repoDir = config.targetRepoDir;
    this.authorName = config.gitAuthorName;
    this.authorEmail = config.gitAuthorEmail;
  }

  _git(args) {
    return execFileSync('git', args, {
      cwd: this.repoDir,
      env: {
        ...process.env,
        GIT_AUTHOR_NAME: this.authorName,
        GIT_AUTHOR_EMAIL: this.authorEmail,
        GIT_COMMITTER_NAME: this.authorName,
        GIT_COMMITTER_EMAIL: this.authorEmail,
      },
      encoding: 'utf8',
    });
  }

  /** 一批變更合併成一次 commit + push；無變更則不 commit（冪等，避免空 commit 洗歷史）。 */
  commitAndPush(summary) {
    this._git(['add', '-A']);
    const status = this._git(['status', '--porcelain']);
    if (!status.trim()) {
      return { committed: false };
    }
    this._git(['commit', '-m', summary]);
    this._git(['push']);
    return { committed: true };
  }
}

module.exports = { GitSync };