const {isUndefined} = require('lodash');
const semver = require('semver');
const {makeTag} = require('./utils');

/**
 * Last release.
 *
 * @typedef {Object} LastRelease
 * @property {string} version The version number of the last release.
 * @property {string} [gitHead] The Git reference used to make the last release.
 */

/**
 * Determine the Git tag and version of the last tagged release.
 *
 * - Filter out the branch tags that are not valid semantic version
 * - Sort the versions
 * - Retrive the highest version
 *
 * @param {Object} context semantic-release context.
 * @param {Object} params Function parameters.
 * @param {Object} params.before Find only releases with version number lower than this version.
 *
 * @return {LastRelease} The last tagged release or empty object if none is found.
 */
module.exports = ({branch: {name, tags, type}, options: {tagFormat}, logger}, {before} = {}) => {
  const [{version, gitTag, gitHead, channel} = {}] = tags
    .filter(tag => type === 'prerelease' || !semver.prerelease(tag.version))
    .filter(tag => isUndefined(before) || semver.lt(tag.version, before))
    .sort((a, b) => semver.rcompare(a.version, b.version));

  if (gitTag) {
    logger.log(`Found git tag ${gitTag} associated with version ${version} on branch ${name}`);
    return {version, gitTag, gitHead, channel, name: makeTag(tagFormat, version)};
  }

  logger.log(`No git tag version found on branch ${name}`);
  return {};
};