import { PackageGroup, VersionType } from '@changesets/types';
import { Package } from '@manypkg/get-packages';
import semverGt from 'semver/functions/gt';
import { InternalRelease } from './types';

export function getHighestReleaseType(
  releases: InternalRelease[],
): VersionType {
  if (releases.length === 0) {
    throw new Error(
      `Large internal Changesets error when calculating highest release type in the set of releases. Please contact the maintainers`,
    );
  }

  let highestReleaseType: VersionType = 'none';

  for (let release of releases) {
    switch (release.type) {
      case 'major':
        return 'major';
      case 'minor':
        highestReleaseType = 'minor';
        break;
      case 'patch':
        if (highestReleaseType === 'none') {
          highestReleaseType = 'patch';
        }
        break;
    }
  }

  return highestReleaseType;
}

export function getCurrentHighestVersion(
  packageGroup: PackageGroup,
  packagesByName: Map<string, Package>,
): string {
  let highestVersion: string | undefined;

  for (let pkgName of packageGroup) {
    let pkg = packagesByName.get(pkgName);

    if (!pkg) {
      console.error(
        `FATAL ERROR IN CHANGESETS! We were unable to version for package group: ${pkgName} in package group: ${packageGroup.toString()}`,
      );
      throw new Error(`fatal: could not resolve linked packages`);
    }

    if (
      highestVersion === undefined ||
      semverGt(pkg.packageJson.version, highestVersion)
    ) {
      highestVersion = pkg.packageJson.version;
    }
  }

  return highestVersion!;
}