// Says whether a push to main brings release commits alone (exit 0) or
// anything else (exit 1), for tool/pre-push, which then skips the checks: a
// release commit changes an app's version and its texts of what's new alone
// (tool/src/release/release_push.dart says why that is enough). Reads what
// git hands a pre-push hook: the remote as the argument, a line per ref pushed
// on stdin (local ref, local commit, remote ref, remote commit), and looks at
// the commits pushed to main that no ref of that remote has yet, as
// tool/check_signatures.sh does.
import 'dart:convert';
import 'dart:io';

import 'src/release/log.dart';
import 'src/release/release_push.dart';
import 'src/release/version.dart';

Future<void> main(List<String> arguments) async {
  final remote = arguments.firstOrNull ?? 'origin';
  final commits = <(Commit, List<String>)>[];
  var pushesMain = false;
  await for (final line
      in stdin.transform(utf8.decoder).transform(const LineSplitter())) {
    final fields = line.trim().split(RegExp(r'\s+'));
    if (fields.length != 4 || fields[2] != 'refs/heads/main') {
      continue;
    }
    final local = fields[1];
    if (RegExp(r'^0+$').hasMatch(local)) {
      continue;
    }
    pushesMain = true;
    final log = await _git([
      'log',
      '--format=$logFormat',
      '--name-only',
      local,
      '--not',
      '--remotes=$remote',
    ]);
    for (final commit in parseLog(log)) {
      final diff = await _git([
        'show',
        '--format=',
        '--unified=0',
        commit.hash,
        '--',
        '*pubspec.yaml',
      ]);
      commits.add((
        commit,
        [
          for (final line in const LineSplitter().convert(diff))
            if ((line.startsWith('+') || line.startsWith('-')) &&
                !line.startsWith('+++') &&
                !line.startsWith('---'))
              line,
        ],
      ));
    }
  }
  if (pushesMain && onlyReleaseCommits(commits)) {
    stdout.writeln(
      '▸ Release commits alone (${commits.map((c) => c.$1.subject).join('; ')}): '
      'no checks needed.',
    );
    exit(0);
  }
  exit(1);
}

Future<String> _git(List<String> arguments) async {
  final result = await Process.run('git', arguments);
  if (result.exitCode != 0) {
    stderr.writeln('git ${arguments.join(' ')}: ${result.stderr}');
    exit(1);
  }
  return '${result.stdout}';
}