// Copyright 2013 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 CHROME_BROWSER_EXTENSIONS_API_MDNS_MDNS_API_H_
#define CHROME_BROWSER_EXTENSIONS_API_MDNS_MDNS_API_H_

#include <set>
#include <string>

#include "base/memory/scoped_ptr.h"
#include "base/threading/thread_checker.h"
#include "chrome/browser/extensions/api/mdns/dns_sd_registry.h"
#include "chrome/browser/extensions/api/profile_keyed_api_factory.h"
#include "extensions/browser/event_router.h"

namespace extensions {

class DnsSdRegistry;

// MDnsAPI is instantiated with the profile and will listen for extensions that
// register listeners for the chrome.mdns extension API. It will use a registry
// class to start the mDNS listener process (if necessary) and observe new
// service events to dispatch them to registered extensions.
class MDnsAPI : public ProfileKeyedAPI,
                public EventRouter::Observer,
                public DnsSdRegistry::DnsSdObserver {
 public:
  explicit MDnsAPI(Profile* profile);
  virtual ~MDnsAPI();

  static MDnsAPI* Get(Profile* profile);

  // ProfileKeyedAPI implementation.
  static ProfileKeyedAPIFactory<MDnsAPI>* GetFactoryInstance();

  // Used to mock out the DnsSdRegistry for testing.
  void SetDnsSdRegistryForTesting(scoped_ptr<DnsSdRegistry> registry);

 protected:
  // Retrieve an instance of the registry. Lazily created when needed.
  virtual DnsSdRegistry* dns_sd_registry();

 private:
  friend class ProfileKeyedAPIFactory<MDnsAPI>;

  // EventRouter::Observer:
  virtual void OnListenerAdded(const EventListenerInfo& details) OVERRIDE;
  virtual void OnListenerRemoved(const EventListenerInfo& details) OVERRIDE;

  // DnsSdRegistry::Observer
  virtual void OnDnsSdEvent(
      const std::string& service_type,
      const DnsSdRegistry::DnsSdServiceList& services) OVERRIDE;

  // ProfileKeyedAPI implementation.
  static const char* service_name() {
    return "MDnsAPI";
  }

  static const bool kServiceIsCreatedWithBrowserContext = true;
  static const bool kServiceIsNULLWhileTesting = true;

  // Update the current list of service types and update the registry.
  void UpdateMDnsListeners(const EventListenerInfo& details);

  // Ensure methods are only called on UI thread.
  base::ThreadChecker thread_checker_;
  Profile* const profile_;
  // Lazily created on first access and destroyed with this API class.
  scoped_ptr<DnsSdRegistry> dns_sd_registry_;
  // Current set of service types registered with the registry.
  std::set<std::string> service_types_;

  DISALLOW_COPY_AND_ASSIGN(MDnsAPI);
};

}  // namespace extensions

#endif  // CHROME_BROWSER_EXTENSIONS_API_MDNS_MDNS_API_H_