// Copyright 2017 The Fuchsia 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 PERIDOT_BIN_SESSIONMGR_AGENT_RUNNER_AGENT_CONTEXT_IMPL_H_
#define PERIDOT_BIN_SESSIONMGR_AGENT_RUNNER_AGENT_CONTEXT_IMPL_H_

#include <string>

#include <fuchsia/auth/cpp/fidl.h>
#include <fuchsia/modular/cpp/fidl.h>
#include <fuchsia/sys/cpp/fidl.h>
#include <lib/async/cpp/operation.h>
#include <lib/component/cpp/service_provider_impl.h>
#include <lib/fidl/cpp/binding.h>
#include <lib/fidl/cpp/binding_set.h>
#include <lib/fxl/macros.h>

#include "peridot/bin/sessionmgr/component_context_impl.h"
#include "peridot/lib/fidl/app_client.h"

namespace modular {

class AgentRunner;

// The parameters of agent context that do not vary by instance.
struct AgentContextInfo {
  const ComponentContextInfo component_context_info;
  fuchsia::sys::Launcher* const launcher;
  fuchsia::auth::TokenManager* const token_manager;
  fuchsia::modular::UserIntelligenceProvider* const user_intelligence_provider;
};

// This class manages an agent and its life cycle. AgentRunner owns this class,
// and instantiates one for every instance of an agent running. All requests for
// this agent (identified for now by the agent's URL) are routed to this
// class. This class manages all AgentControllers associated with this agent.
class AgentContextImpl : fuchsia::modular::AgentContext,
                         fuchsia::modular::AgentController,
                         fuchsia::auth::TokenManager {
 public:
  // Starts the agent specified in |agent_config| and provides it:
  //  1) AgentContext service
  //  2) A set of services from UserIntelligenceProvider for this agent's url.
  explicit AgentContextImpl(const AgentContextInfo& info,
                            fuchsia::modular::AppConfig agent_config);
  ~AgentContextImpl() override;

  // Stops the running agent, irrespective of whether there are active
  // AgentControllers or outstanding tasks. Calls into
  // |AgentRunner::RemoveAgent()| to remove itself.
  void StopForTeardown();

  // Called by AgentRunner when a component wants to connect to this agent.
  // Connections will pend until fuchsia::modular::Agent::Initialize() responds
  // back, at which point all connections will be forwarded to the agent.
  void NewAgentConnection(
      const std::string& requestor_url,
      fidl::InterfaceRequest<fuchsia::sys::ServiceProvider>
          incoming_services_request,
      fidl::InterfaceRequest<fuchsia::modular::AgentController>
          agent_controller_request);

  // Called by AgentRunner when the framework wants to talk to the
  // |fuchsia::modular::EntityProvider| service from this agent. Similar to
  // NewAgentConnection(), this operation will pend until the entity provider
  // agent is initialized.
  void NewEntityProviderConnection(
      fidl::InterfaceRequest<fuchsia::modular::EntityProvider>
          entity_provider_request,
      fidl::InterfaceRequest<fuchsia::modular::AgentController>
          agent_controller_request);

  // Called by AgentRunner when a new task has been scheduled.
  void NewTask(const std::string& task_id);

  enum class State { INITIALIZING, RUNNING, TERMINATING };
  State state() { return state_; }

 private:
  // |fuchsia::modular::AgentContext|
  void GetComponentContext(
      fidl::InterfaceRequest<fuchsia::modular::ComponentContext> request)
      override;
  // |fuchsia::modular::AgentContext|
  void GetTokenManager(
      fidl::InterfaceRequest<fuchsia::auth::TokenManager> request) override;
  // |fuchsia::modular::AgentContext|
  void ScheduleTask(fuchsia::modular::TaskInfo task_info) override;
  // |fuchsia::modular::AgentContext|
  void DeleteTask(std::string task_id) override;
  // |fuchsia::modular::AgentContext|
  void GetEntityReferenceFactory(
      fidl::InterfaceRequest<fuchsia::modular::EntityReferenceFactory> request)
      override;

  // |fuchsia::auth::TokenManager|
  void Authorize(fuchsia::auth::AppConfig app_config,
                 fidl::InterfaceHandle<fuchsia::auth::AuthenticationUIContext>
                     auth_ui_context,
                 std::vector<::std::string> app_scopes,
                 fidl::StringPtr user_profile_id, fidl::StringPtr auth_code,
                 AuthorizeCallback callback) override;

  // |fuchsia::auth::TokenManager|
  void GetAccessToken(fuchsia::auth::AppConfig app_config,
                      std::string user_profile_id,
                      std::vector<::std::string> app_scopes,
                      GetAccessTokenCallback callback) override;

  // |fuchsia::auth::TokenManager|
  void GetIdToken(fuchsia::auth::AppConfig app_config,
                  std::string user_profile_id, fidl::StringPtr audience,
                  GetIdTokenCallback callback) override;

  // |fuchsia::auth::TokenManager|
  void GetFirebaseToken(fuchsia::auth::AppConfig app_config,
                        std::string user_profile_id,
                        std::string audience,
                        std::string firebase_api_key,
                        GetFirebaseTokenCallback callback) override;

  // |fuchsia::auth::TokenManager|
  void DeleteAllTokens(fuchsia::auth::AppConfig app_config,
                       std::string user_profile_id,
                       DeleteAllTokensCallback callback) override;

  // |fuchsia::auth::TokenManager|
  void ListProfileIds(fuchsia::auth::AppConfig app_config,
                      ListProfileIdsCallback callback) override;

  // Adds an operation on |operation_queue_|. This operation is immediately
  // Done() if this agent is not |ready_|. Else if there are no active
  // AgentControllers and no outstanding task, fuchsia::modular::Agent.Stop() is
  // called with a timeout.
  void StopAgentIfIdle();

  const std::string url_;

  std::unique_ptr<AppClient<fuchsia::modular::Lifecycle>> app_client_;
  fuchsia::modular::AgentPtr agent_;
  fidl::BindingSet<fuchsia::modular::AgentContext> agent_context_bindings_;
  fidl::BindingSet<fuchsia::modular::AgentController>
      agent_controller_bindings_;
  fidl::BindingSet<fuchsia::auth::TokenManager> token_manager_bindings_;

  AgentRunner* const agent_runner_;

  ComponentContextImpl component_context_impl_;

  // A service provider that represents the services to be added into an
  // application's namespace.
  component::ServiceProviderImpl service_provider_impl_;

  fuchsia::auth::TokenManager* const token_manager_;    // Not owned.
  EntityProviderRunner* const entity_provider_runner_;  // Not owned.
  fuchsia::modular::UserIntelligenceProvider* const
      user_intelligence_provider_;  // Not owned.

  State state_ = State::INITIALIZING;

  // Number of times fuchsia::modular::Agent.RunTask() was called but we're
  // still waiting on its completion callback.
  int incomplete_task_count_ = 0;

  OperationQueue operation_queue_;

  // Operations implemented here.
  class InitializeCall;
  class StopCall;

  FXL_DISALLOW_COPY_AND_ASSIGN(AgentContextImpl);
};

}  // namespace modular

#endif  // PERIDOT_BIN_SESSIONMGR_AGENT_RUNNER_AGENT_CONTEXT_IMPL_H_