import path from "path";
import fs from "fs-extra";
import semver from "semver";
import { Native, Local } from "./loadingStrategies";
import { CompilerSupplier } from "./index";

/**
 * takes a version string which may be native or local, and resolves
 * it to one which is (presumably) either a version or a version range
 */
export function resolveToRange(version?: string): string {
  if (!version) {
    return CompilerSupplier.getDefaultVersion();
  }

  //if version was native or local, must determine what version that
  //actually corresponds to
  if (version === "native") {
    return new Native().load().version();
  } else if (fs.existsSync(version) && path.isAbsolute(version)) {
    return new Local().load(version).version();
  }
  return version;
}

/**
 * parameter range may be either an individual version or a range
 */
export function rangeContainsAtLeast(
  range: string,
  comparisonVersion: string
): boolean {
  //the following line works with prereleases
  const individualAtLeast = !!(
    semver.valid(range, { loose: true }) &&
    semver.gte(range, comparisonVersion, {
      includePrerelease: true,
      loose: true
    })
  );
  //the following line doesn't, despite the flag, but does work with version ranges
  const rangeAtLeast = !!(
    semver.validRange(range, { loose: true }) &&
    !semver.gtr(comparisonVersion, range, {
      includePrerelease: true,
      loose: true
    }) //intersects will throw if given undefined so must ward against
  );
  return individualAtLeast || rangeAtLeast;
}