const logger = require('logplease').create('runtime');
const semver = require('semver');
const config = require('./config');
const globals = require('./globals');
const fss = require('fs');
const path = require('path');

const runtimes = [];

class Runtime {
  constructor({ language, version, aliases, pkgdir, runtime }) {
    this.language = language;
    this.version = version;
    this.aliases = aliases || [];
    this.pkgdir = pkgdir;
    this.runtime = runtime;
  }

  static load_package(package_dir) {
    let info = JSON.parse(
      fss.read_file_sync(path.join(package_dir, 'pkg-info.json'))
    );

    let { language, version, build_platform, aliases, provides } = info;
    version = semver.parse(version);

    if (build_platform !== globals.platform) {
      logger.warn(
        `Package ${language}-${version} was built for platform ${build_platform}, ` +
          `but our platform is ${globals.platform}`
      );
    }

    if (provides) {
      // Multiple languages in 1 package
      provides.forEach((lang) => {
        runtimes.push(
          new Runtime({
            language: lang.language,
            aliases: lang.aliases,
            version,
            pkgdir: package_dir,
            runtime: language,
          })
        );
      });
    } else {
      runtimes.push(
        new Runtime({
          language,
          version,
          aliases,
          pkgdir: package_dir,
        })
      );
    }

    logger.debug(`Package ${language}-${version} was loaded`);
  }

  get compiled() {
    if (this._compiled === undefined) {
      this._compiled = fss.exists_sync(path.join(this.pkgdir, 'compile'));
    }

    return this._compiled;
  }

  get env_vars() {
    if (!this._env_vars) {
      const env_file = path.join(this.pkgdir, '.env');
      const env_content = fss.read_file_sync(env_file).toString();

      this._env_vars = {};

      env_content
        .trim()
        .split('\n')
        .map((line) => line.split('=', 2))
        .forEach(([key, val]) => {
          this._env_vars[key.trim()] = val.trim();
        });
    }

    return this._env_vars;
  }

  toString() {
    return `${this.language}-${this.version.raw}`;
  }

  unregister() {
    const index = runtimes.indexOf(this);
    runtimes.splice(index, 1); //Remove from runtimes list
  }
}

module.exports = runtimes;
module.exports.Runtime = Runtime;
module.exports.get_runtimes_matching_language_version = function (lang, ver) {
  return runtimes.filter(
    (rt) =>
      (rt.language == lang || rt.aliases.includes(lang)) &&
      semver.satisfies(rt.version, ver)
  );
};
module.exports.get_latest_runtime_matching_language_version = function (
  lang,
  ver
) {
  return module.exports
    .get_runtimes_matching_language_version(lang, ver)
    .sort((a, b) => semver.rcompare(a.version, b.version))[0];
};

module.exports.get_runtime_by_name_and_version = function (runtime, ver) {
  return runtimes.find(
    (rt) =>
      (rt.runtime == runtime ||
        (rt.runtime === undefined && rt.language == runtime)) &&
      semver.satisfies(rt.version, ver)
  );
};

module.exports.load_package = Runtime.load_package;