Mock up code completion.

dart/sdk/lib/_internal/compiler/samples/leap_server/leap_server.dart

 // Copyright (c) 2012, 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.
 
 library leap_server;
 
 import 'dart:io';
 
+import 'dart:convert' show JSON, HtmlEscape;
+
+/// Represents a "project" command. These commands are accessed from the URL
+/// "/project?name".
+class ProjectCommand {
+  final String name;
+
+  /// For each query parameter, this map describes rules for validating them.
+  final Map<String, String> rules;
+
+  final Function handle;
+
+  const ProjectCommand(this.name, this.rules, this.handle);
+}
+
 class Conversation {
   HttpRequest request;
   HttpResponse response;
 
+  static const String PROJECT_PATH = '/project';
+
+  static const String PACKAGES_PATH = '/packages';
+
   static const String CONTENT_TYPE = HttpHeaders.CONTENT_TYPE;
 
-  static const String LEAP_LANDING_PAGE =
-      'sdk/lib/_internal/compiler/samples/leap/index.html';
+  static Uri documentRoot = Uri.base;
 
-  static String landingPage = LEAP_LANDING_PAGE;
+  static Uri projectRoot = Uri.base.resolve('site/try/src/');
+
+  static Uri packageRoot = Uri.base.resolve('sdk/lib/_internal/');
+
+  static const List<ProjectCommand> COMMANDS = const <ProjectCommand>[
+      const ProjectCommand('list', const {'list': null}, handleProjectList),
+  ];
 
   Conversation(this.request, this.response);
 
   onClosed(_) {
     if (response.statusCode == HttpStatus.OK) return;
     print('Request for ${request.uri} ${response.statusCode}');
   }
 
   notFound(path) {
     response.statusCode = HttpStatus.NOT_FOUND;
     response.write(htmlInfo('Not Found',
                             'The file "$path" could not be found.'));
     response.close();
   }
 
   redirect(String location) {
     response.statusCode = HttpStatus.FOUND;
     response.headers.add(HttpHeaders.LOCATION, location);
     response.close();
   }
 
+  badRequest(String problem) {
+    response.statusCode = HttpStatus.BAD_REQUEST;
+    response.write(htmlInfo("Bad request",
+                            "Bad request '${request.uri}': $problem"));
+    response.close();
+  }
+
+  bool validate(Map<String, String> parameters, Map<String, String> rules) {
+    Iterable<String> problems = rules.keys
+        .where((name) => !parameters.containsKey(name))
+        .map((name) => "Missing parameter: '$name'.");
+    if (!problems.isEmpty) {
+      badRequest(problems.first);
+      return false;
+    }
+    Set extra = new Set.from(parameters.keys)..removeAll(rules.keys);
+    if (extra.isEmpty) return true;
+    String extraString = (extra.toList()..sort()).join("', '");
+    badRequest("Extra parameters: '$extraString'.");
+    return false;
+  }
+
+  static handleProjectList(Conversation self) {
+    String nativeDir = projectRoot.toFilePath();
+    Directory dir = new Directory(nativeDir);
+    var future = dir.list(recursive: true, followLinks: false).toList();
+    future.then((List<FileSystemEntity> entries) {
+      List<String> files = entries
+          .map((e) => e.path)
+          .where((p) => !p.endsWith('~') && p.startsWith(nativeDir))
+          .map((p) => p.substring(nativeDir.length))
+          .map((p) => new Uri.file(p).path).toList();
+      self.response
+          ..write(JSON.encode(files))
+          ..close();
+    });
+  }
+
+  handleProjectRequest() {
+    Map<String, String> parameters = request.uri.queryParameters;
+    for (ProjectCommand command in COMMANDS) {
+      if (parameters.containsKey(command.name)) {
+        if (validate(parameters, command.rules)) {
+          (command.handle)(this);
+        }
+        return;
+      }
+    }
+    String commands = COMMANDS.map((c) => c.name).join("', '");
+    badRequest("Valid commands are: '$commands'");
+  }
+
   handle() {
     response.done
       .then(onClosed)
       .catchError(onError);
 
-    String path = request.uri.path;
-    if (path == '/') return redirect('/$landingPage');
-    if (path == '/favicon.ico') {
-      path = '/sdk/lib/_internal/dartdoc/static/favicon.ico';
+    Uri uri = request.uri;
+    if (uri.path == PROJECT_PATH) {
+      return handleProjectRequest();
     }
-    if (path.contains('..') || path.contains('%')) return notFound(path);
-    var f = new File("./$path");
+    if (uri.path.endsWith('/')) {
+      uri = uri.resolve('index.html');
+    }
+    if (uri.path == '/css/fonts/fontawesome-webfont.woff') {
+      uri = uri.resolve('/fontawesome-webfont.woff');
+    }
+    if (uri.path.contains('..') || uri.path.contains('%')) {
+      return notFound(uri.path);
+    }
+    String path = uri.path;
+    Uri root = documentRoot;
+    String dartType = 'application/dart';
+    if (path.startsWith('/project/packages/')) {
+      root = packageRoot;
+      path = path.substring('/project/packages'.length);
+    } else if (path.startsWith('${PROJECT_PATH}/')) {
+      root = projectRoot;
+      path = path.substring(PROJECT_PATH.length);
+      dartType = 'text/plain';
+    } else if (path.startsWith('${PACKAGES_PATH}/')) {
+      root = packageRoot;
+      path = path.substring(PACKAGES_PATH.length);
+    }
+    var f = new File(root.resolve('.$path').toFilePath());
     f.exists().then((bool exists) {
       if (!exists) return notFound(path);
       if (path.endsWith('.html')) {
         response.headers.set(CONTENT_TYPE, 'text/html');
       } else if (path.endsWith('.dart')) {
-        response.headers.set(CONTENT_TYPE, 'application/dart');
+        response.headers.set(CONTENT_TYPE, dartType);
       } else if (path.endsWith('.js')) {
         response.headers.set(CONTENT_TYPE, 'application/javascript');
       } else if (path.endsWith('.ico')) {
         response.headers.set(CONTENT_TYPE, 'image/x-icon');
       } else if (path.endsWith('.appcache')) {
         response.headers.set(CONTENT_TYPE, 'text/cache-manifest');
       }
       f.openRead().pipe(response).catchError(onError);
     });
   }
 
   static onRequest(HttpRequest request) {
     new Conversation(request, request.response).handle();
   }
 
   static onError(error) {
     if (error is HttpException) {
       print('Error: ${error.message}');
     } else {
       print('Error: ${error}');
     }
   }
 
   String htmlInfo(String title, String text) {
+    // No script injection, please.
+    title = const HtmlEscape().convert(title);
+    text = const HtmlEscape().convert(text);
     return """
 <!DOCTYPE html>
 <html lang='en'>
 <head>
 <title>$title</title>
 </head>
 <body>
 <h1>$title</h1>
 <p>$text</p>
 </body>
 </html>
 """;
   }
 }
 
 main(List<String> arguments) {
   if (arguments.length > 0) {
-    Conversation.landingPage = arguments[0];
+    Conversation.documentRoot = Uri.base.resolve(arguments[0]);
   }
   var host = '127.0.0.1';
   if (arguments.length > 1) {
     host = arguments[1];
   }
   int port = 0;
   if (arguments.length > 2) {
     port = int.parse(arguments[2]);
   }
+  if (arguments.length > 3) {
+    Conversation.projectRoot = Uri.base.resolve(arguments[3]);
+  }
+  if (arguments.length > 4) {
+    Conversation.packageRoot = Uri.base.resolve(arguments[4]);
+  }
   HttpServer.bind(host, port).then((HttpServer server) {
     print('HTTP server started on http://$host:${server.port}/');
     server.listen(Conversation.onRequest, onError: Conversation.onError);
   }).catchError((e) {
     print("HttpServer.bind error: $e");
     exit(1);
   });
 }