/*eslint-disable no-console*/
const exec = require('shell-utils').exec;
const p = require('path');
const semver = require('semver');
const fs = require('fs');

const ONLY_ON_BRANCH = 'v2';
const VERSION_TAG = 'alpha';
const VERSION_INC = 'patch';

function validateEnv() {
  if (!process.env.CI || !process.env.TRAVIS) {
    throw new Error(`releasing is only available from Travis CI`);
  }

  if (process.env.TRAVIS_PULL_REQUEST !== 'false') {
    console.log(`not publishing as triggered by pull request ${process.env.TRAVIS_PULL_REQUEST}`);
    return false;
  }

  if (process.env.TRAVIS_BRANCH !== ONLY_ON_BRANCH) {
    console.log(`not publishing on branch ${process.env.TRAVIS_BRANCH}`);
    return false;
  }

  return true;
}

function setupGit() {
  exec.execSyncSilent(`git config --global push.default simple`);
  exec.execSyncSilent(`git config --global user.email "${process.env.GIT_EMAIL}"`);
  exec.execSyncSilent(`git config --global user.name "${process.env.GIT_USER}"`);
  const remoteUrl = new RegExp(`https?://(\\S+)`).exec(exec.execSyncRead(`git remote -v`))[1];
  exec.execSyncSilent(`git remote add deploy "https://${process.env.GIT_USER}:${process.env.GIT_TOKEN}@${remoteUrl}"`);
  exec.execSync(`git checkout ${ONLY_ON_BRANCH}`);
}

function getNextVersion() {
  const packageVersion = semver.clean(process.env.npm_package_version);
  console.log(`package version: ${packageVersion}`);
  const current = exec.execSyncRead(`npm view ${process.env.npm_package_name} dist-tags.${VERSION_TAG}`);
  console.log(`current published version: ${current}`);

  if (semver.gt(packageVersion, current)) {
    return packageVersion;
  } else {
    return semver.inc(current, VERSION_INC);
  }
}

function calcNewVersion() {
  let candidate = getNextVersion();
  while (isAlreadyPublished(candidate)) {
    console.log(`${candidate} already published`);
    candidate = semver.inc(candidate, VERSION_INC);
  }
  return candidate;
}

function isAlreadyPublished(version) {
  return exec.execSyncRead(`npm view ${process.env.npm_package_name}@${version} version`).length > 0;
}

function createNpmRc() {
  const content = `
email=\${NPM_EMAIL}
//registry.npmjs.org/:_authToken=\${NPM_TOKEN}
`;
  fs.writeFileSync(`.npmrc`, content);
}

function tagAndPublish(newVersion) {
  exec.execSync(`npm version ${newVersion} -m "v${newVersion} [ci skip]"`);
  exec.execSync(`npm publish --tag ${VERSION_TAG}`);
  exec.execSyncSilent(`git push deploy --tags || true`);
}

function run() {
  if (!validateEnv()) {
    return;
  }
  setupGit();
  createNpmRc();
  const newVersion = calcNewVersion();
  console.log(`new version is: ${newVersion}`);
  tagAndPublish(newVersion);
}

run();