// Copyright (c) 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_LOCATION_LOCATION_MANAGER_H_
#define CHROME_BROWSER_EXTENSIONS_API_LOCATION_LOCATION_MANAGER_H_

#include <string>

#include "base/scoped_observer.h"
#include "extensions/browser/browser_context_keyed_api_factory.h"
#include "extensions/browser/extension_registry_observer.h"

namespace content {
class BrowserContext;
struct Geoposition;
}  // namespace content

namespace extensions {
class ExtensionRegistry;
class LocationManager;
class LocationRequest;

namespace api {
namespace location {

struct Coordinates;

}  // namespace location
}  // namespace api

// BrowserContext's manager of all location watch requests created by
// chrome.location API. Lives in the UI thread.
class LocationManager : public BrowserContextKeyedAPI,
                        public ExtensionRegistryObserver {
 public:
  explicit LocationManager(content::BrowserContext* context);
  ~LocationManager() override;

  // Adds location request for the given extension, and starts the location
  // tracking.
  void AddLocationRequest(
      const std::string& extension_id,
      const std::string& request_name,
      const double* distance_update_threshold_meters,
      const double* time_between_updates_ms);

  // Cancels and removes the request with the given |name| for the given
  // extension.
  void RemoveLocationRequest(const std::string& extension_id,
                             const std::string& name);

  // BrowserContextKeyedAPI implementation.
  static BrowserContextKeyedAPIFactory<LocationManager>* GetFactoryInstance();

  // Convenience method to get the LocationManager for a context.
  static LocationManager* Get(content::BrowserContext* context);

 private:
  friend class LocationRequest;
  friend class BrowserContextKeyedAPIFactory<LocationManager>;

  typedef std::string ExtensionId;
  typedef scoped_refptr<LocationRequest> LocationRequestPointer;
  typedef std::multimap<ExtensionId, LocationRequestPointer> LocationRequestMap;
  typedef LocationRequestMap::iterator LocationRequestIterator;

  // Converts |position| from GeolocationProvider to the location API
  // |coordinates|.
  static void GeopositionToApiCoordinates(
      const content::Geoposition& position,
      api::location::Coordinates* coordinates);

  // Sends a location update to the extension.
  void SendLocationUpdate(const std::string& extension_id,
                          const std::string& request_name,
                          const content::Geoposition& position);

  // ExtensionRegistryObserver implementation.
  void OnExtensionLoaded(content::BrowserContext* browser_context,
                         const Extension* extension) override;
  void OnExtensionUnloaded(content::BrowserContext* browser_context,
                           const Extension* extension,
                           UnloadedExtensionInfo::Reason reason) override;

  // BrowserContextKeyedAPI implementation.
  static const char* service_name() { return "LocationManager"; }

  content::BrowserContext* const browser_context_;

  // A map of our pending location requests, per extension.
  // Invariant: None of the LocationRequestLists are empty.
  LocationRequestMap location_requests_;

  ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
      extension_registry_observer_;

  DISALLOW_COPY_AND_ASSIGN(LocationManager);
};

}  // namespace extensions

#endif  // CHROME_BROWSER_EXTENSIONS_API_LOCATION_LOCATION_MANAGER_H_