// Copyright (c) 2012 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.

#include "chromeos/dbus/session_manager_client.h"

#include "base/bind.h"
#include "base/callback.h"
#include "base/string_util.h"
#include "dbus/bus.h"
#include "dbus/message.h"
#include "dbus/object_path.h"
#include "dbus/object_proxy.h"
#include "third_party/cros_system_api/dbus/service_constants.h"

namespace chromeos {

// The SessionManagerClient implementation used in production.
class SessionManagerClientImpl : public SessionManagerClient {
 public:
  explicit SessionManagerClientImpl(dbus::Bus* bus)
      : session_manager_proxy_(NULL),
        screen_locked_(false),
        weak_ptr_factory_(this) {
    session_manager_proxy_ = bus->GetObjectProxy(
        login_manager::kSessionManagerServiceName,
        dbus::ObjectPath(login_manager::kSessionManagerServicePath));

    session_manager_proxy_->ConnectToSignal(
        chromium::kChromiumInterface,
        chromium::kOwnerKeySetSignal,
        base::Bind(&SessionManagerClientImpl::OwnerKeySetReceived,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&SessionManagerClientImpl::SignalConnected,
                   weak_ptr_factory_.GetWeakPtr()));

    session_manager_proxy_->ConnectToSignal(
        chromium::kChromiumInterface,
        chromium::kPropertyChangeCompleteSignal,
        base::Bind(&SessionManagerClientImpl::PropertyChangeCompleteReceived,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&SessionManagerClientImpl::SignalConnected,
                   weak_ptr_factory_.GetWeakPtr()));

    session_manager_proxy_->ConnectToSignal(
        chromium::kChromiumInterface,
        chromium::kLockScreenSignal,
        base::Bind(&SessionManagerClientImpl::ScreenLockReceived,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&SessionManagerClientImpl::SignalConnected,
                   weak_ptr_factory_.GetWeakPtr()));

    session_manager_proxy_->ConnectToSignal(
        chromium::kChromiumInterface,
        chromium::kUnlockScreenSignal,
        base::Bind(&SessionManagerClientImpl::ScreenUnlockReceived,
                   weak_ptr_factory_.GetWeakPtr()),
        base::Bind(&SessionManagerClientImpl::SignalConnected,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  virtual ~SessionManagerClientImpl() {
  }

  // SessionManagerClient overrides:
  virtual void AddObserver(Observer* observer) OVERRIDE {
    observers_.AddObserver(observer);
  }

  virtual void RemoveObserver(Observer* observer) OVERRIDE {
    observers_.RemoveObserver(observer);
  }

  virtual bool HasObserver(Observer* observer) OVERRIDE {
    return observers_.HasObserver(observer);
  }

  virtual void EmitLoginPromptReady() OVERRIDE {
    SimpleMethodCallToSessionManager(
        login_manager::kSessionManagerEmitLoginPromptReady);
  }

  virtual void EmitLoginPromptVisible() OVERRIDE {
    SimpleMethodCallToSessionManager(
        login_manager::kSessionManagerEmitLoginPromptVisible);
  }

  virtual void RestartJob(int pid, const std::string& command_line) OVERRIDE {
    dbus::MethodCall method_call(login_manager::kSessionManagerInterface,
                                 login_manager::kSessionManagerRestartJob);
    dbus::MessageWriter writer(&method_call);
    writer.AppendInt32(pid);
    writer.AppendString(command_line);
    session_manager_proxy_->CallMethod(
        &method_call,
        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
        base::Bind(&SessionManagerClientImpl::OnRestartJob,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  virtual void RestartEntd() OVERRIDE {
    SimpleMethodCallToSessionManager(login_manager::kSessionManagerRestartEntd);
  }

  virtual void StartSession(const std::string& user_email) OVERRIDE {
    dbus::MethodCall method_call(login_manager::kSessionManagerInterface,
                                 login_manager::kSessionManagerStartSession);
    dbus::MessageWriter writer(&method_call);
    writer.AppendString(user_email);
    writer.AppendString("");  // Unique ID is deprecated
    session_manager_proxy_->CallMethod(
        &method_call,
        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
        base::Bind(&SessionManagerClientImpl::OnStartSession,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  virtual void StopSession() OVERRIDE {
    dbus::MethodCall method_call(login_manager::kSessionManagerInterface,
                                 login_manager::kSessionManagerStopSession);
    dbus::MessageWriter writer(&method_call);
    writer.AppendString("");  // Unique ID is deprecated
    session_manager_proxy_->CallMethod(
        &method_call,
        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
        base::Bind(&SessionManagerClientImpl::OnStopSession,
                   weak_ptr_factory_.GetWeakPtr()));
  }

  virtual void RequestLockScreen() OVERRIDE {
    SimpleMethodCallToSessionManager(login_manager::kSessionManagerLockScreen);
  }

  virtual void RequestUnlockScreen() OVERRIDE {
    SimpleMethodCallToSessionManager(
        login_manager::kSessionManagerUnlockScreen);
  }

  virtual bool GetIsScreenLocked() OVERRIDE {
    return screen_locked_;
  }

  virtual void RetrieveDevicePolicy(
      const RetrievePolicyCallback& callback) OVERRIDE {
    CallRetrievePolicy(login_manager::kSessionManagerRetrievePolicy,
                       callback);
  }

  virtual void RetrieveUserPolicy(
      const RetrievePolicyCallback& callback) OVERRIDE {
    CallRetrievePolicy(login_manager::kSessionManagerRetrieveUserPolicy,
                       callback);
  }

  virtual void StoreDevicePolicy(const std::string& policy_blob,
                                 const StorePolicyCallback& callback) OVERRIDE {
    CallStorePolicy(login_manager::kSessionManagerStorePolicy,
                    policy_blob, callback);
  }

  virtual void StoreUserPolicy(const std::string& policy_blob,
                               const StorePolicyCallback& callback) OVERRIDE {
    CallStorePolicy(login_manager::kSessionManagerStoreUserPolicy,
                    policy_blob, callback);
  }

 private:
  // Makes a method call to the session manager with no arguments and no
  // response.
  void SimpleMethodCallToSessionManager(const std::string& method_name) {
    dbus::MethodCall method_call(login_manager::kSessionManagerInterface,
                                 method_name);
    session_manager_proxy_->CallMethod(
        &method_call,
        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
        dbus::ObjectProxy::EmptyResponseCallback());
  }

  // Helper for Retrieve{User,Device}Policy.
  virtual void CallRetrievePolicy(const std::string& method_name,
                                  const RetrievePolicyCallback& callback) {
    dbus::MethodCall method_call(login_manager::kSessionManagerInterface,
                                 method_name);
    session_manager_proxy_->CallMethod(
        &method_call,
        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
        base::Bind(&SessionManagerClientImpl::OnRetrievePolicy,
                   weak_ptr_factory_.GetWeakPtr(),
                   method_name,
                   callback));
  }

  // Helper for Store{User,Device}Policy.
  virtual void CallStorePolicy(const std::string& method_name,
                               const std::string& policy_blob,
                               const StorePolicyCallback& callback) {
    dbus::MethodCall method_call(login_manager::kSessionManagerInterface,
                                 method_name);
    dbus::MessageWriter writer(&method_call);
    // static_cast does not work due to signedness.
    writer.AppendArrayOfBytes(
        reinterpret_cast<const uint8*>(policy_blob.data()), policy_blob.size());
    session_manager_proxy_->CallMethod(
        &method_call,
        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
        base::Bind(&SessionManagerClientImpl::OnStorePolicy,
                   weak_ptr_factory_.GetWeakPtr(),
                   method_name,
                   callback));
  }

  // Called when kSessionManagerRestartJob method is complete.
  void OnRestartJob(dbus::Response* response) {
    LOG_IF(ERROR, !response)
        << "Failed to call "
        << login_manager::kSessionManagerRestartJob;
  }

  // Called when kSessionManagerStartSession method is complete.
  void OnStartSession(dbus::Response* response) {
    LOG_IF(ERROR, !response)
        << "Failed to call "
        << login_manager::kSessionManagerStartSession;
  }

  // Called when kSessionManagerStopSession method is complete.
  void OnStopSession(dbus::Response* response) {
    LOG_IF(ERROR, !response)
        << "Failed to call "
        << login_manager::kSessionManagerStopSession;
  }

  // Called when kSessionManagerRetrievePolicy or
  // kSessionManagerRetrieveUserPolicy  method is complete.
  void OnRetrievePolicy(const std::string& method_name,
                        const RetrievePolicyCallback& callback,
                        dbus::Response* response) {
    if (!response) {
      LOG(ERROR) << "Failed to call " << method_name;
      callback.Run("");
      return;
    }
    dbus::MessageReader reader(response);
    uint8* values = NULL;
    size_t length = 0;
    if (!reader.PopArrayOfBytes(&values, &length)) {
      LOG(ERROR) << "Invalid response: " << response->ToString();
      callback.Run("");
      return;
    }
    // static_cast does not work due to signedness.
    std::string serialized_proto(reinterpret_cast<char*>(values), length);
    callback.Run(serialized_proto);
  }

  // Called when kSessionManagerStorePolicy or kSessionManagerStoreUserPolicy
  // method is complete.
  void OnStorePolicy(const std::string& method_name,
                     const StorePolicyCallback& callback,
                     dbus::Response* response) {
    bool success = false;
    if (!response) {
      LOG(ERROR) << "Failed to call " << method_name;
    } else {
      dbus::MessageReader reader(response);
      if (!reader.PopBool(&success))
        LOG(ERROR) << "Invalid response: " << response->ToString();
    }
    callback.Run(success);
  }

  // Called when the owner key set signal is received.
  void OwnerKeySetReceived(dbus::Signal* signal) {
    dbus::MessageReader reader(signal);
    std::string result_string;
    if (!reader.PopString(&result_string)) {
      LOG(ERROR) << "Invalid signal: " << signal->ToString();
      return;
    }
    const bool success = StartsWithASCII(result_string, "success", false);
    FOR_EACH_OBSERVER(Observer, observers_, OwnerKeySet(success));
  }

  // Called when the property change complete signal is received.
  void PropertyChangeCompleteReceived(dbus::Signal* signal) {
    dbus::MessageReader reader(signal);
    std::string result_string;
    if (!reader.PopString(&result_string)) {
      LOG(ERROR) << "Invalid signal: " << signal->ToString();
      return;
    }
    const bool success = StartsWithASCII(result_string, "success", false);
    FOR_EACH_OBSERVER(Observer, observers_, PropertyChangeComplete(success));
  }

  void ScreenLockReceived(dbus::Signal* signal) {
    screen_locked_ = true;
    FOR_EACH_OBSERVER(Observer, observers_, LockScreen());
  }

  void ScreenUnlockReceived(dbus::Signal* signal) {
    screen_locked_ = false;
    FOR_EACH_OBSERVER(Observer, observers_, UnlockScreen());
  }

  // Called when the object is connected to the signal.
  void SignalConnected(const std::string& interface_name,
                       const std::string& signal_name,
                       bool success) {
    LOG_IF(ERROR, !success) << "Failed to connect to " << signal_name;
  }

  dbus::ObjectProxy* session_manager_proxy_;
  ObserverList<Observer> observers_;
  bool screen_locked_;
  base::WeakPtrFactory<SessionManagerClientImpl> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(SessionManagerClientImpl);
};

// The SessionManagerClient implementation used on Linux desktop,
// which does nothing.
class SessionManagerClientStubImpl : public SessionManagerClient {
 public:
  SessionManagerClientStubImpl() : screen_locked_(false) {}
  virtual ~SessionManagerClientStubImpl() {}

  // SessionManagerClient overrides.
  virtual void AddObserver(Observer* observer) OVERRIDE {
    observers_.AddObserver(observer);
  }
  virtual void RemoveObserver(Observer* observer) OVERRIDE {
    observers_.RemoveObserver(observer);
  }
  virtual bool HasObserver(Observer* observer) OVERRIDE {
    return observers_.HasObserver(observer);
  }
  virtual void EmitLoginPromptReady() OVERRIDE {}
  virtual void EmitLoginPromptVisible() OVERRIDE {}
  virtual void RestartJob(int pid, const std::string& command_line) OVERRIDE {}
  virtual void RestartEntd() OVERRIDE {}
  virtual void StartSession(const std::string& user_email) OVERRIDE {}
  virtual void StopSession() OVERRIDE {}
  virtual void RequestLockScreen() OVERRIDE {
    screen_locked_ = true;
    FOR_EACH_OBSERVER(Observer, observers_, LockScreen());
  }
  virtual void RequestUnlockScreen() OVERRIDE {
    screen_locked_ = false;
    FOR_EACH_OBSERVER(Observer, observers_, UnlockScreen());
  }
  virtual bool GetIsScreenLocked() OVERRIDE { return screen_locked_; }
  virtual void RetrieveDevicePolicy(
      const RetrievePolicyCallback& callback) OVERRIDE {
    callback.Run("");
  }
  virtual void RetrieveUserPolicy(
      const RetrievePolicyCallback& callback) OVERRIDE {
    callback.Run("");
  }
  virtual void StoreDevicePolicy(const std::string& policy_blob,
                                 const StorePolicyCallback& callback) OVERRIDE {
    callback.Run(true);
  }
  virtual void StoreUserPolicy(const std::string& policy_blob,
                               const StorePolicyCallback& callback) OVERRIDE {
    callback.Run(true);
  }

 private:
  ObserverList<Observer> observers_;
  bool screen_locked_;

  DISALLOW_COPY_AND_ASSIGN(SessionManagerClientStubImpl);
};

SessionManagerClient::SessionManagerClient() {
}

SessionManagerClient::~SessionManagerClient() {
}

SessionManagerClient* SessionManagerClient::Create(
    DBusClientImplementationType type,
    dbus::Bus* bus) {
  if (type == REAL_DBUS_CLIENT_IMPLEMENTATION)
    return new SessionManagerClientImpl(bus);
  DCHECK_EQ(STUB_DBUS_CLIENT_IMPLEMENTATION, type);
  return new SessionManagerClientStubImpl();
}

}  // namespace chromeos