// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef IOS_WEB_WEB_THREAD_IMPL_H_
#define IOS_WEB_WEB_THREAD_IMPL_H_

#include "base/callback.h"
#include "base/threading/thread.h"
#include "ios/web/public/web_thread.h"

namespace web {

class WebTestSuiteListener;

class WebThreadImpl : public WebThread, public base::Thread {
 public:
  // Construct a WebThreadImpl with the supplied identifier.  It is an error
  // to construct a WebThreadImpl that already exists.
  explicit WebThreadImpl(WebThread::ID identifier);

  // Special constructor for the main (UI) thread and unittests. If a
  // |message_loop| is provied, we use a dummy thread here since the main
  // thread already exists.
  WebThreadImpl(WebThread::ID identifier, base::MessageLoop* message_loop);
  ~WebThreadImpl() override;

  bool Start();
  bool StartWithOptions(const Options& options);
  bool StartAndWaitForTesting();

  // Creates and registers a TaskExecutor that facilitates posting tasks to a
  // WebThread via //base/task/post_task.h.
  static void CreateTaskExecutor();

  // Unregister and delete the TaskExecutor after a test.
  static void ResetTaskExecutorForTesting();

  // Resets globals for |identifier|. Used in tests to clear global state that
  // would otherwise leak to the next test. Globals are not otherwise fully
  // cleaned up in ~WebThreadImpl() as there are subtle differences between
  // UNINITIALIZED and SHUTDOWN state (e.g. globals.task_runners are kept around
  // on shutdown). Must be called after ~WebThreadImpl() for the given
  // |identifier|.
  //
  // Also unregisters and deletes the TaskExecutor.
  static void ResetGlobalsForTesting(WebThread::ID identifier);

 protected:
  void Init() override;
  void Run(base::RunLoop* run_loop) override;
  void CleanUp() override;

 private:
  // This class implements all the functionality of the public WebThread
  // functions, but state is stored in the WebThreadImpl to keep
  // the API cleaner. Therefore make WebThread a friend class.
  friend class WebThread;

  // The following are unique function names that makes it possible to tell
  // the thread id from the callstack alone in crash dumps.
  void UIThreadRun(base::RunLoop* run_loop);
  void IOThreadRun(base::RunLoop* run_loop);

  // Common initialization code for the constructors.
  void Initialize();

  // For testing.
  friend class TestWebThreadBundle;
  friend class TestWebThreadBundleImpl;
  friend class WebTestSuiteListener;

  // The identifier of this thread.  Only one thread can exist with a given
  // identifier at a given time.
  ID identifier_;
};

}  // namespace web

#endif  // IOS_WEB_WEB_THREAD_IMPL_H_