Move pub's arg parsing to bin/pub.dart.

sdk/lib/_internal/pub/bin/pub.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-import '../lib/src/pub.dart';
+import 'dart:async';
+import 'dart:io';
+import 'dart:math' as math;
 
-// TODO(nweiz): move option-parsing logic into this file.
-void main() => run();
+import 'package:args/args.dart';
+import 'package:pathos/path.dart' as path;
+
+import '../lib/src/command.dart';
+import '../lib/src/exit_codes.dart' as exit_codes;
+import '../lib/src/log.dart' as log;
+import '../lib/src/sdk.dart' as sdk;
+import '../lib/src/system_cache.dart';
+import '../lib/src/utils.dart';
+
+/// The parser for arguments that are global to Pub rather than specific to a
+/// single command.
+ArgParser get pubArgParser {
+  var parser = new ArgParser();
+  parser.addFlag('help', abbr: 'h', negatable: false,
+      help: 'Print this usage information.');
+  parser.addFlag('version', negatable: false,
+      help: 'Print pub version.');
+  parser.addFlag('trace',
+       help: 'Print debugging information when an error occurs.');
+  parser.addOption('verbosity',
+      help: 'Control output verbosity.',
+      allowed: ['normal', 'io', 'solver', 'all'],
+      allowedHelp: {
+        'normal': 'Show errors, warnings, and user messages.',
+        'io':     'Also show IO operations.',
+        'solver': 'Show steps during version resolution.',
+        'all':    'Show all output including internal tracing messages.'
+      });
+  parser.addFlag('verbose', abbr: 'v', negatable: false,
+      help: 'Shortcut for "--verbosity=all"');
+  return parser;
+}
+
+void main() {
+  var globalOptions;
+  try {
+    globalOptions = pubArgParser.parse(new Options().arguments);
+  } on FormatException catch (e) {
+    log.error(e.message);
+    log.error('Run "pub help" to see available options.');
+    exit(exit_codes.USAGE);
+  }
+
+  if (globalOptions['version']) {
+    log.message('Pub ${sdk.version}');
+    return;
+  }
+
+  if (globalOptions['help'] || globalOptions.rest.isEmpty) {
+    printUsage();
+    return;
+  }
+
+  if (globalOptions['trace']) {
+    log.recordTranscript();
+  }
+
+  switch (globalOptions['verbosity']) {
+    case 'normal': log.showNormal(); break;
+    case 'io': log.showIO(); break;
+    case 'solver': log.showSolver(); break;
+    case 'all': log.showAll(); break;
+    default:
+      // No specific verbosity given, so check for the shortcut.
+      if (globalOptions['verbose']) {
+        log.showAll();
+      } else {
+        log.showNormal();
+      }
+      break;
+  }
+
+  var cacheDir;
+  if (Platform.environment.containsKey('PUB_CACHE')) {
+    cacheDir = Platform.environment['PUB_CACHE'];
+  } else if (Platform.operatingSystem == 'windows') {
+    var appData = Platform.environment['APPDATA'];
+    cacheDir = path.join(appData, 'Pub', 'Cache');
+  } else {
+    cacheDir = '${Platform.environment['HOME']}/.pub-cache';
+  }
+
+  validatePlatform().then((_) {
+    var cache = new SystemCache.withSources(cacheDir);
+
+    // Select the command.
+    var command = PubCommand.commands[globalOptions.rest[0]];
+    if (command == null) {
+      log.error('Could not find a command named "${globalOptions.rest[0]}".');
+      log.error('Run "pub help" to see available commands.');
+      exit(exit_codes.USAGE);
+      return;
+    }
+
+    var commandArgs = globalOptions.rest.sublist(1);
+    command.run(cache, globalOptions, commandArgs);
+  });
+}
+
+/// Checks that pub is running on a supported platform. If it isn't, it prints
+/// an error message and exits. Completes when the validation is done.
+Future validatePlatform() {
+  return new Future.sync(() {
+    if (Platform.operatingSystem != 'windows') return;
+
+    return runProcess('ver', []).then((result) {
+      if (result.stdout.join('\n').contains('XP')) {
+        log.error('Sorry, but pub is not supported on Windows XP.');
+        exit(exit_codes.USAGE);
+      }
+    });
+  });
+}
+
+/// Displays usage information for the app.
+void printUsage([String description = 'Pub is a package manager for Dart.']) {
+  // Build up a buffer so it shows up as a single log entry.
+  var buffer = new StringBuffer();
+  buffer.write(description);
+  buffer.write('\n\n');
+  buffer.write('Usage: pub command [arguments]\n\n');
+  buffer.write('Global options:\n');
+  buffer.write('${pubArgParser.getUsage()}\n\n');
+
+  // Show the commands sorted.
+  buffer.write('Available commands:\n');
+
+  // TODO(rnystrom): A sorted map would be nice.
+  int length = 0;
+  var names = <String>[];
+  for (var command in PubCommand.commands.keys) {
+    // Hide aliases.
+    if (PubCommand.commands[command].aliases.indexOf(command) >= 0) continue;
+    length = math.max(length, command.length);
+    names.add(command);
+  }
+
+  names.sort((a, b) => a.compareTo(b));
+
+  for (var name in names) {
+    buffer.write('  ${padRight(name, length)}   '
+        '${PubCommand.commands[name].description}\n');
+  }
+
+  buffer.write('\n');
+  buffer.write(
+      'Use "pub help [command]" for more information about a command.');
+  log.message(buffer.toString());
+}