// https://docs.github.com/en/actions/learn-github-actions/environment-variables#default-environment-variables
const {parseBranch} = require('../lib/utils.js');

const getPrEvent = ({env}) => {
  try {
    const event = env.GITHUB_EVENT_PATH ? require(env.GITHUB_EVENT_PATH) : undefined;

    if (event && event.pull_request) {
      return {
        branch: event.pull_request.base ? parseBranch(event.pull_request.base.ref) : undefined,
        pr: event.pull_request.number,
      };
    }
  } catch {
    // Noop
  }

  return {pr: undefined, branch: undefined};
};

const getPrNumber = (env) => {
  const event = env.GITHUB_EVENT_PATH ? require(env.GITHUB_EVENT_PATH) : undefined;
  return event && event.pull_request ? event.pull_request.number : undefined;
};

module.exports = {
  detect({env}) {
    return Boolean(env.GITHUB_ACTIONS);
  },
  configuration({env, cwd}) {
    const isPr = env.GITHUB_EVENT_NAME === 'pull_request' || env.GITHUB_EVENT_NAME === 'pull_request_target';
    const branch = parseBranch(
      env.GITHUB_EVENT_NAME === 'pull_request_target' ? `refs/pull/${getPrNumber(env)}/merge` : env.GITHUB_REF
    );

    return {
      name: 'GitHub Actions',
      service: 'github',
      commit: env.GITHUB_SHA,
      build: env.GITHUB_RUN_ID,
      isPr,
      branch,
      prBranch: isPr ? branch : undefined,
      slug: env.GITHUB_REPOSITORY,
      root: env.GITHUB_WORKSPACE,
      ...(isPr ? getPrEvent({env, cwd}) : undefined),
    };
  },
};