import semverInc from 'semver/functions/inc';
import { InternalRelease, PreInfo } from './types';
import { InternalError } from '@changesets/errors';

export function incrementVersion(
  release: InternalRelease,
  preInfo: PreInfo | undefined,
) {
  if (release.type === 'none') {
    return release.oldVersion;
  }

  let version = semverInc(release.oldVersion, release.type)!;
  if (preInfo !== undefined && preInfo.state.mode !== 'exit') {
    let preVersion = preInfo.preVersions.get(release.name);
    if (preVersion === undefined) {
      throw new InternalError(
        `preVersion for ${release.name} does not exist when preState is defined`,
      );
    }
    // why are we adding this ourselves rather than passing 'pre' + versionType to semver.inc?
    // because semver.inc with prereleases is confusing and this seems easier
    version += `-${preInfo.state.tag}.${preVersion}`;
  }
  return version;
}