import 'dart:io';

import '../command.dart';
import '../local_state.dart' show joinPath;

const _largeClaudeMdWarningChars = 40000;

Future<CommandResult> run(CommandContext context, List<String> args) async {
  final workingDirectory = Directory(context.workingDirectory);
  final legacyRoot = Directory(joinPath(context.workingDirectory, 'old_repo'));
  final claudeMdFile = File(
    joinPath(joinPath(context.workingDirectory, '.the_agency'), 'THE_AGENCY.md'),
  );
  final hasGit = await Directory(joinPath(context.workingDirectory, '.git')).exists();
  final hasLegacyPackageManifest =
      await File(joinPath(legacyRoot.path, 'package.json')).exists() ||
      await File(joinPath(legacyRoot.path, 'tsconfig.json')).exists();
  final configFile = File(context.settingsStore.path);
  final runtimeFile = File(context.runtimeStateStore.path);

  context.writeLine('Doctor');
  context.writeLine(
    'Runtime: Dart ${Platform.version.split(' ').first} on ${Platform.operatingSystem}',
  );
  context.writeLine('Working directory: ${workingDirectory.path}');
  context.writeLine('');

  context.writeLine(
    '[ok] settings: ${await configFile.exists() ? context.settingsStore.path : 'missing'}',
  );
  context.writeLine(
    '[ok] runtime state: ${await runtimeFile.exists() ? context.runtimeStateStore.path : 'missing'}',
  );
  context.writeLine(
    '[${await legacyRoot.exists() ? 'ok' : 'warn'}] legacy source root: ${legacyRoot.path}',
  );
  context.writeLine(
    '[${hasGit ? 'ok' : 'warn'}] git repository: ${hasGit ? 'detected' : 'not detected'}',
  );

  if (await claudeMdFile.exists()) {
    final length = await claudeMdFile.length();
    final level = length > _largeClaudeMdWarningChars ? 'warn' : 'ok';
    context.writeLine(
      '[$level] THE_AGENCY.md: ${claudeMdFile.path} (${length.toString()} bytes)',
    );
  } else {
    context.writeLine('[warn] THE_AGENCY.md: not found');
  }

  context.writeLine(
    '[${hasLegacyPackageManifest ? 'ok' : 'warn'}] legacy manifests: ${hasLegacyPackageManifest ? 'detected' : 'old_repo has no package.json or tsconfig.json at its root'}',
  );
  context.writeLine('');
  context.writeLine('Notes:');
  if (!hasGit) {
    context.writeLine('  - This workspace is not currently inside a git repository.');
  }
  if (!hasLegacyPackageManifest) {
    context.writeLine(
      '  - Exact legacy runtime reproduction is harder because old_repo lacks a checked-in package manifest.',
    );
  }
  if (!await legacyRoot.exists()) {
    context.writeLine('  - old_repo is missing, so legacy source parity checks cannot run.');
  }
  if (hasGit && hasLegacyPackageManifest && await legacyRoot.exists()) {
    context.writeLine('  - No obvious environment blockers detected.');
  }

  return const CommandResult();
}