// This function takes in changesets and returns one release per
// package listed in the changesets

import { shouldSkipPackage } from '@changesets/should-skip-package';
import { Config, NewChangeset } from '@changesets/types';
import { Package } from '@manypkg/get-packages';
import { InternalRelease } from './types';

export default function flattenReleases(
  changesets: NewChangeset[],
  packagesByName: Map<string, Package>,
  config: Config,
): Map<string, InternalRelease> {
  let releases: Map<string, InternalRelease> = new Map();

  changesets.forEach((changeset) => {
    changeset.releases
      // Filter out skipped packages because they should not trigger a release
      // If their dependencies need updates, they will be added to releases by `determineDependents()` with release type `none`
      .filter(
        ({ name }) =>
          !shouldSkipPackage(packagesByName.get(name)!, {
            ignore: config.ignore,
            allowPrivatePackages: config.privatePackages.version,
          }),
      )
      .forEach(({ name, type }) => {
        let release = releases.get(name);
        let pkg = packagesByName.get(name);
        if (!pkg) {
          throw new Error(
            `"${changeset.id}" changeset mentions a release for a package "${name}" but such a package could not be found.`,
          );
        }
        if (!release) {
          release = {
            name,
            type,
            oldVersion: pkg.packageJson.version,
            changesets: [changeset.id],
          };
        } else {
          if (
            type === 'major' ||
            ((release.type === 'patch' || release.type === 'none') &&
              (type === 'minor' || type === 'patch'))
          ) {
            release.type = type;
          }
          // Check whether the bumpType will change
          // If the bumpType has changed recalc newVersion
          // push new changeset to releases
          release.changesets.push(changeset.id);
        }

        releases.set(name, release);
      });
  });

  return releases;
}