/*
 * Copyright 2011 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.gwt.dev.codeserver;

import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.util.log.PrintWriterTreeLogger;
import com.google.gwt.util.tools.Utility;

import java.io.File;
import java.io.IOException;

/**
 * <p>This class contains the {@link #main main method} that starts the code server for
 * "Super Dev Mode", a replacement for developer mode that doesn't require
 * browser plugins.</p>
 *
 * <p>This tool is EXPERIMENTAL. There is no authentication, no encryption, no XSS
 * protection,  and it makes all source code on the GWT compiler's classpath available
 * via HTTP. It is only safe to run on localhost (the default).</p>
 */
public class CodeServer {

  /**
   * Starts the code server. Shuts down the JVM if startup fails.
   * @param args Command-line options that can be parsed by {@link Options}.
   */
  public static void main(String[] args) throws Exception {

    Options options = new Options();
    if (!options.parseArgs(args)) {
      System.exit(1);
    }

    main(options);
  }

  /**
   * Starts the code server with the given options. Shuts down the JVM if startup fails.
   */
  public static void main(Options options) {
    if (options.isCompileTest()) {
      PrintWriterTreeLogger logger = new PrintWriterTreeLogger();
      logger.setMaxDetail(TreeLogger.Type.INFO);
      try {
        makeModules(options, logger);
      } catch (Throwable t) {
        t.printStackTrace();
        System.out.println("FAIL");
        System.exit(1);
      }
      System.out.println("PASS");
      System.exit(0);
    }

    try {
      start(options);

      String url = "http://" + options.getPreferredHost() + ":" + options.getPort() + "/";

      System.out.println();
      System.out.println("The code server is ready.");
      System.out.println("Next, visit: " + url);
    } catch (Throwable t) {
      t.printStackTrace();
      System.exit(1);
    }
  }

  /**
   * Starts the code server with the given command line options. To shut it down, see
   * {@link WebServer#stop}.
   *
   * <p>Only one code server should be started at a time because the GWT compiler uses
   * a lot of static variables.</p>
   */
  public static WebServer start(Options options) throws IOException, UnableToCompleteException {
    PrintWriterTreeLogger logger = new PrintWriterTreeLogger();
    logger.setMaxDetail(TreeLogger.Type.INFO);

    Modules modules = makeModules(options, logger);

    SourceHandler sourceHandler = new SourceHandler(modules, logger);

    WebServer webServer = new WebServer(sourceHandler, modules,
        options.getBindAddress(), options.getPort(), logger);
    webServer.start();

    return webServer;
  }

  /**
   * Configures and compiles all the modules (unless {@link Options#getNoPrecompile} is false).
   */
  private static Modules makeModules(Options options, PrintWriterTreeLogger logger)
      throws IOException, UnableToCompleteException {

    File workDir = ensureWorkDir(options);
    System.out.println("workDir: " + workDir);

    Modules modules = new Modules();
    for (String moduleName : options.getModuleNames()) {
      AppSpace appSpace = AppSpace.create(new File(workDir, moduleName));

      Recompiler recompiler = new Recompiler(appSpace, moduleName, options, logger);
      modules.addModuleState(new ModuleState(recompiler, logger, options.getNoPrecompile()));
    }
    return modules;
  }

  /**
   * Ensures that we have a work directory. If specified via a flag, the
   * directory must already exist. Otherwise, create a temp directory.
   */
  private static File ensureWorkDir(Options options) throws IOException {
    File workDir = options.getWorkDir();
    if (workDir == null) {
      workDir = Utility.makeTemporaryDirectory(null, "gwt-codeserver-");
    } else {
      if (!workDir.isDirectory()) {
        throw new IOException("workspace directory doesn't exist: " + workDir);
      }
    }
    return workDir;
  }
}