/* eslint-disable no-console */
/* eslint-env node */
'use strict';

const versionParser = require('./version-parser.js');
const { isValidStableVersion, incrementPatch } = require('./version-parser.js');

const latestVersion = getLatestVersionTag();
let newVersion = '';

try {
  if (process.env.TAG) {
    // write the version field in the package json to the version in the git tag
    const tag = process.env.TAG;
    if (!versionParser.isValidVersion(tag)) {
      throw new Error(`Unsupported tag for release: "${tag}"`);
    }
    // remove v
    newVersion = tag.substring(1);
    if (!versionParser.isDefinitelyGreaterThanCanaries(newVersion)) {
      // 1.2.3-0.canary.500
      // 1.2.3-0.canary.501
      // 1.2.3-0.caaanary.custom => bad
      // 1.2.3-0.caaanary.custom.0.canary.503 => now lower than 1.2.3-0.canary.501
      throw new Error(
        `It's possible that "${newVersion}" has a lower precedense than an existing canary version which is not allowed.`,
      );
    }
  } else {
    // bump patch in version from latest git tag
    let intermediateVersion = latestVersion;
    const isStable = isValidStableVersion(intermediateVersion);

    // if last git tagged version is a prerelease we should append `.0.<type>.<commit num>`
    // if the last git tagged version is a stable version then we should append `-0.<type>.<commit num>` and increment the patch
    // `type` can be `pr`, `branch`, or `canary`
    if (isStable) {
      intermediateVersion = incrementPatch(intermediateVersion);
    }

    // remove v
    intermediateVersion = intermediateVersion.substring(1);

    const suffix = process.env.CF_PAGES
      ? `pr.${process.env.CF_PAGES_BRANCH.replace(
          /[^a-zA-Z-]/g,
          '-',
        )}.${getCommitHash().slice(0, 8)}`
      : `0.canary.${getCommitNum()}`;

    newVersion = `${intermediateVersion}${isStable ? '-' : '.'}${suffix}`;
  }

  if (!versionParser.isGreaterOrEqual(newVersion, latestVersion)) {
    throw new Error(
      `New version "${newVersion}" is not >= latest version "${latestVersion}" on this branch.`,
    );
  }

  const foundPreviousVersion = versionParser
    .getPotentialPreviousStableVersions(`v${newVersion}`)
    .every((potentialPreviousVersion) =>
      hasTag(`v${potentialPreviousVersion}`),
    );
  if (!foundPreviousVersion) {
    throw new Error(
      'Could not find a previous version. The tag must follow a previous stable version number.',
    );
  }

  console.log(newVersion);
} catch (e) {
  console.error(e);
  process.exit(1);
}
process.exit(0);

function getCommitNum() {
  return parseInt(exec('git rev-list --count HEAD'), 10);
}

function getCommitHash() {
  return exec('git rev-parse HEAD');
}

function getLatestVersionTag() {
  let commitish = '';
  // eslint-disable-next-line no-constant-condition
  while (true) {
    const tag = exec('git describe --tag --abbrev=0 --match="v*" ' + commitish);
    if (!tag) {
      throw new Error('Could not find tag.');
    }
    if (versionParser.isValidVersion(tag)) {
      return tag;
    }
    // next time search older tags than this one
    commitish = tag + '~1';
  }
}

function hasTag(tag) {
  try {
    exec(`git rev-parse "refs/tags/${tag}"`);
    return true;
  } catch (e) {
    return false;
  }
}

function exec(cmd) {
  return require('child_process')
    .execSync(cmd, { stdio: 'pipe' })
    .toString()
    .trim();
}