import 'dart:io';

import 'package:podman/podman.dart';

Future<void> main(List<String> args) async {
  if (args.isEmpty || args.contains('--help') || args.contains('-h')) {
    _printUsage();
    return;
  }

  final flags = args
      .where((arg) => arg.startsWith('--'))
      .toList(growable: false);
  final positional = args
      .where((arg) => !arg.startsWith('--'))
      .toList(growable: false);

  if (positional.isEmpty) {
    stderr.writeln('Provide at least one container or pod name.');
    _printUsage();
    exitCode = 64;
    return;
  }

  final kubeOutPath = _readOption(flags, 'kube-out');
  final systemdDirPath = _readOption(flags, 'systemd-dir');
  final systemdTarget =
      _readOption(flags, 'systemd-target') ?? positional.first;

  final includeService = !flags.contains('--no-service');
  final podmanOnly = !flags.contains('--no-podman-only');
  final noTrunc = flags.contains('--no-trunc');

  final client = PodmanClient();
  try {
    final kubeYaml = await client.generateKube(
      GenerateKubeOptions(
        names: positional,
        service: includeService,
        podmanOnly: podmanOnly,
        noTrunc: noTrunc,
      ),
    );

    if (kubeOutPath != null && kubeOutPath.isNotEmpty) {
      await File(kubeOutPath).writeAsString(kubeYaml);
      print('Wrote generated Kubernetes YAML to $kubeOutPath');
    } else {
      print('--- begin generated kube yaml ---');
      print(kubeYaml.trim());
      print('--- end generated kube yaml ---');
    }

    final systemd = await client.generateSystemd(
      systemdTarget,
      options: const GenerateSystemdOptions(
        useName: true,
        noHeader: true,
        restartPolicy: 'always',
      ),
    );

    if (systemd.units.isEmpty) {
      print('No systemd units were generated for "$systemdTarget".');
      return;
    }

    if (systemdDirPath != null && systemdDirPath.isNotEmpty) {
      final outputDir = Directory(systemdDirPath);
      await outputDir.create(recursive: true);

      for (final entry in systemd.units.entries) {
        final file = File('${outputDir.path}/${entry.key}');
        await file.writeAsString(entry.value);
        print('Wrote ${entry.key}');
      }
    } else {
      print('Generated systemd units: ${systemd.units.keys.toList()..sort()}');
    }
  } finally {
    await client.close();
  }
}

String? _readOption(List<String> args, String name) {
  final prefix = '--$name=';
  for (final arg in args) {
    if (arg.startsWith(prefix)) {
      return arg.substring(prefix.length);
    }
  }
  return null;
}

void _printUsage() {
  print('''
Generate assets example

Usage:
  dart run example/generate_assets_example.dart <name> [name ...] [options]

Examples:
  dart run example/generate_assets_example.dart groupware-orchestrator
  dart run example/generate_assets_example.dart groupware-pod --kube-out=./stack.yaml --systemd-dir=./units

Options:
  --kube-out=<path>         Write generated kube YAML to file (default: stdout)
  --systemd-dir=<path>      Write generated systemd units to directory
  --systemd-target=<name>   Specific name for systemd generation (defaults to first positional)
  --no-service              Do not include generated Service objects in kube YAML
  --no-podman-only          Do not include Podman-only annotations in kube YAML
  --no-trunc                Use non-truncated annotations
  --help, -h                Show this help
''');
}