import 'dart:io';

import 'package:args/command_runner.dart';
import 'package:pipe/src/cli.dart';
import 'package:pipe/src/errors.dart';

/// Exit codes:
///
/// - 0: success.
/// - 1: a gate failed: `check --fail-on`, `verify --expect-resolved`,
///   `recall --strict`, `index --fail-on-error`, or `guide --yams` could not
///   persist.
/// - 2: pipe could not do what was asked (a [PipeException], or a filesystem
///   error such as an unreadable or unwritable path).
/// - 64: invalid command-line usage.
Future<void> main(List<String> arguments) async {
  final runner = PipeRunner();
  try {
    exitCode = await runner.run(arguments) ?? 0;
  } on PipeException catch (error) {
    stderr.writeln(error);
    exitCode = 2;
  } on FileSystemException catch (error) {
    // Any filesystem failure not already turned into a PipeException still gets
    // a one-line message and a documented exit code, not a stack trace and 255.
    stderr.writeln(
      'pipe: ${error.message}'
      '${error.path == null ? '' : ': ${error.path}'}'
      '${error.osError == null ? '' : ' (${error.osError!.message})'}',
    );
    exitCode = 2;
  } on UsageException catch (error) {
    stderr.writeln(error.message);
    stderr.writeln(error.usage);
    exitCode = 64;
  } catch (error, stack) {
    // Anything else is a pipe bug. Say so in one line with the documented
    // "could not do what was asked" code instead of a raw trace and exit 255;
    // PIPE_DEBUG=1 restores the trace for a bug report.
    stderr.writeln('pipe: internal error: $error');
    if (Platform.environment['PIPE_DEBUG'] == '1') {
      stderr.writeln(stack);
    } else {
      stderr.writeln('pipe: rerun with PIPE_DEBUG=1 for a stack trace');
    }
    exitCode = 2;
  }
}