import 'dart:async';
import 'dart:convert';
import 'dart:io';

/// Runs each integration test file sequentially to avoid multi-app start issues on desktop.
///
/// Usage:
///   dart tool/run_integration_tests.dart [--device=<id>] [--reporter=<name>] [--pattern=<glob>]
///
/// Defaults:
///   --device=linux
///   --reporter=compact
///   --pattern=*.dart (all files in integration_test/)
Future<int> main(List<String> args) async {
  String device = 'linux';
  String reporter = 'compact';
  String pattern = '*.dart';

  for (int i = 0; i < args.length; i++) {
    final a = args[i];
    if (a.startsWith('--device=')) {
      device = a.substring(a.indexOf('=') + 1);
    } else if (a == '--device' || a == '-d') {
      if (i + 1 < args.length) {
        device = args[++i];
      }
    } else if (a.startsWith('-d=')) {
      device = a.substring(a.indexOf('=') + 1);
    } else if (a.startsWith('--reporter=')) {
      reporter = a.substring(a.indexOf('=') + 1);
    } else if (a == '--reporter' || a == '-r') {
      if (i + 1 < args.length) {
        reporter = args[++i];
      }
    } else if (a.startsWith('--pattern=')) {
      pattern = a.substring(a.indexOf('=') + 1);
    } else if (a == '--pattern') {
      if (i + 1 < args.length) {
        pattern = args[++i];
      }
    }
  }

  final dir = Directory('integration_test');
  if (!await dir.exists()) {
    stderr.writeln('integration_test/ not found. Run from the project root.');
    return 2;
  }

  final files =
      (await dir
            .list()
            .where((e) => e is File && e.path.endsWith('.dart'))
            .cast<File>()
            .toList())
        ..sort((a, b) => a.path.compareTo(b.path));

  List<File> selected;
  if (pattern == '*.dart') {
    selected = files;
  } else {
    // very simple glob: supports prefix/suffix match
    if (pattern.startsWith('*')) {
      final suffix = pattern.substring(1);
      selected = files.where((f) => f.path.endsWith(suffix)).toList();
    } else if (pattern.endsWith('*')) {
      final prefix = pattern.substring(0, pattern.length - 1);
      selected =
          files
              .where(
                (f) => f.path
                    .split(Platform.pathSeparator)
                    .last
                    .startsWith(prefix),
              )
              .toList();
    } else {
      selected = files.where((f) => f.path.contains(pattern)).toList();
    }
  }

  if (selected.isEmpty) {
    stderr.writeln('No integration tests matched pattern: $pattern');
    return 3;
  }

  stdout.writeln(
    'Running ${selected.length} integration test file(s) sequentially...',
  );
  final results = <String, int>{};

  for (final f in selected) {
    final rel = f.path;
    stdout.writeln('\n=== Running: $rel ===');
    final args = <String>['test', rel, '-d', device, '-r', reporter];
    final proc = await Process.start('flutter', args);
    // Pipe output live
    unawaited(proc.stdout.transform(utf8.decoder).forEach(stdout.write));
    unawaited(proc.stderr.transform(utf8.decoder).forEach(stderr.write));
    final code = await proc.exitCode;
    results[rel] = code;
    if (code == 0) {
      stdout.writeln('=== PASSED: $rel ===');
    } else {
      stderr.writeln('=== FAILED (exit $code): $rel ===');
    }
    // Small pause between launches to let desktop/device settle
    await Future<void>.delayed(const Duration(milliseconds: 300));
  }

  stdout.writeln('\nSummary:');
  var failures = 0;
  for (final entry in results.entries) {
    final status = entry.value == 0 ? 'PASS' : 'FAIL(${entry.value})';
    stdout.writeln(' - ${entry.key}: $status');
    if (entry.value != 0) failures += 1;
  }

  return failures == 0 ? 0 : 1;
}