/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_bluetooth_BluetoothReplyRunnable_h
#define mozilla_dom_bluetooth_BluetoothReplyRunnable_h

#include "mozilla/Attributes.h"
#include "BluetoothCommon.h"
#include "nsThreadUtils.h"
#include "js/Value.h"

class nsIDOMDOMRequest;

namespace mozilla {
namespace dom {
class Promise;
}
}

BEGIN_BLUETOOTH_NAMESPACE

class BluetoothReply;

class BluetoothReplyRunnable : public nsRunnable
{
public:
  NS_DECL_NSIRUNNABLE

  BluetoothReplyRunnable(nsIDOMDOMRequest* aReq,
                         Promise* aPromise = nullptr);

  void SetReply(BluetoothReply* aReply);

  void SetError(const nsAString& aErrorString,
                const enum BluetoothStatus aErrorStatus = STATUS_FAIL)
  {
    mErrorString = aErrorString;
    mErrorStatus = aErrorStatus;
  }

  virtual void ReleaseMembers();

protected:
  virtual ~BluetoothReplyRunnable();

  virtual bool ParseSuccessfulReply(JS::MutableHandle<JS::Value> aValue) = 0;

  // This is an autoptr so we don't have to bring the ipdl include into the
  // header. We assume we'll only be running this once and it should die on
  // scope out of Run() anyways.
  nsAutoPtr<BluetoothReply> mReply;

private:
  nsresult FireReplySuccess(JS::Handle<JS::Value> aVal);
  nsresult FireErrorString();

  virtual void OnSuccessFired();
  virtual void OnErrorFired();

  /**
   * Either mDOMRequest or mPromise is not nullptr to reply applications
   * success or error string. One special case is internal IPC that require
   * neither mDOMRequest nor mPromise to reply applications.
   * E.g., GetAdaptersTask triggered by BluetoothManager
   *
   * TODO: remove mDOMRequest once all methods adopt Promise.
   */
  nsCOMPtr<nsIDOMDOMRequest> mDOMRequest;
  RefPtr<Promise> mPromise;

  BluetoothStatus mErrorStatus;
  nsString mErrorString;
};

class BluetoothVoidReplyRunnable : public BluetoothReplyRunnable
{
public:
  BluetoothVoidReplyRunnable(nsIDOMDOMRequest* aReq,
                             Promise* aPromise = nullptr);
 ~BluetoothVoidReplyRunnable();

protected:
  virtual bool
  ParseSuccessfulReply(JS::MutableHandle<JS::Value> aValue) override
  {
    aValue.setUndefined();
    return true;
  }
};

class BluetoothReplyTaskQueue : public nsRunnable
{
public:
  NS_DECL_NSIRUNNABLE

  class SubReplyRunnable : public BluetoothReplyRunnable
  {
  public:
    SubReplyRunnable(nsIDOMDOMRequest* aReq,
                     Promise* aPromise,
                     BluetoothReplyTaskQueue* aRootQueue);
    ~SubReplyRunnable();

    BluetoothReplyTaskQueue* GetRootQueue() const;

  private:
    virtual void OnSuccessFired() override;
    virtual void OnErrorFired() override;

    RefPtr<BluetoothReplyTaskQueue> mRootQueue;
  };
  friend class BluetoothReplyTaskQueue::SubReplyRunnable;

  class VoidSubReplyRunnable : public SubReplyRunnable
  {
  public:
    VoidSubReplyRunnable(nsIDOMDOMRequest* aReq,
                         Promise* aPromise,
                         BluetoothReplyTaskQueue* aRootQueue);
    ~VoidSubReplyRunnable();

  protected:
    virtual bool ParseSuccessfulReply(
      JS::MutableHandle<JS::Value> aValue) override;
  };

  class SubTask
  {
    NS_INLINE_DECL_THREADSAFE_REFCOUNTING(SubTask)
  public:
    SubTask(BluetoothReplyTaskQueue* aRootQueue,
            SubReplyRunnable* aReply);

    BluetoothReplyTaskQueue* GetRootQueue() const;
    SubReplyRunnable* GetReply() const;

    /*
     * Use SubReplyRunnable as the reply runnable to execute the task.
     *
     * Example:
     * <pre>
     * <code>
     * bool SomeInheritedSubTask::Execute()
     * {
     *   BluetoothService* bs = BluetoothService::Get();
     *   if (!bs) {
     *     return false;
     *   }
     *   bs->DoSomethingInternal(
     *     aSomeParameter,
     *     new SomeInheritedSubReplyRunnable(aSomeDOMRequest,
     *                                       aSomePromise,
     *                                       GetRootQueue()));
     *   return true;
     * }
     * </code>
     * </pre>
     */
    virtual bool Execute() = 0;

  protected:
    virtual ~SubTask();

  private:
    RefPtr<BluetoothReplyTaskQueue> mRootQueue;
    RefPtr<SubReplyRunnable> mReply;
  };

  BluetoothReplyTaskQueue(BluetoothReplyRunnable* aReply);

  void AppendTask(already_AddRefed<SubTask> aTask);

protected:
  ~BluetoothReplyTaskQueue();

  void FireSuccessReply();
  void FireErrorReply();

private:
  void Clear();

  void OnSubReplySuccessFired(SubReplyRunnable* aSubReply);
  void OnSubReplyErrorFired(SubReplyRunnable* aSubReply);

  virtual void OnSuccessFired();
  virtual void OnErrorFired();

  RefPtr<BluetoothReplyRunnable> mReply;
  nsTArray<RefPtr<SubTask>> mTasks;
};

END_BLUETOOTH_NAMESPACE

#endif // mozilla_dom_bluetooth_BluetoothReplyRunnable_h