// Copyright 2014 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/network/auto_connect_handler.h"

#include <sstream>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/location.h"
#include "base/single_thread_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/values.h"
#include "chromeos/dbus/dbus_thread_manager.h"
#include "chromeos/dbus/shill_manager_client.h"
#include "chromeos/dbus/shill_service_client.h"
#include "chromeos/network/device_state.h"
#include "chromeos/network/managed_network_configuration_handler.h"
#include "chromeos/network/network_connection_handler.h"
#include "chromeos/network/network_event_log.h"
#include "chromeos/network/network_state.h"
#include "chromeos/network/network_type_pattern.h"
#include "dbus/object_path.h"
#include "third_party/cros_system_api/dbus/service_constants.h"

namespace chromeos {

namespace {

void DisconnectErrorCallback(
    const std::string& network_path,
    const std::string& error_name,
    std::unique_ptr<base::DictionaryValue> error_data) {
  std::stringstream error_data_ss;
  if (error_data)
    error_data_ss << *error_data;
  else
    error_data_ss << "<none>";

  NET_LOG(ERROR) << "AutoConnectHandler.Disconnect failed. "
                 << "Path: \"" << network_path << "\", "
                 << "Error name: \"" << error_name << "\", "
                 << "Error data: " << error_data_ss.str();
}

void RemoveNetworkConfigurationErrorCallback(
    const std::string& error_name,
    std::unique_ptr<base::DictionaryValue> error_data) {
  std::stringstream error_data_ss;
  if (error_data)
    error_data_ss << *error_data;
  else
    error_data_ss << "<none>";
  NET_LOG(ERROR) << "AutoConnectHandler RemoveNetworkConfiguration failed. "
                 << "Error name: \"" << error_name << "\", "
                 << "Error data: " << error_data_ss.str();
}

void SetPropertiesErrorCallback(
    const std::string& error_name,
    std::unique_ptr<base::DictionaryValue> error_data) {
  std::stringstream error_data_ss;
  if (error_data)
    error_data_ss << *error_data;
  else
    error_data_ss << "<none>";
  NET_LOG(ERROR) << "AutoConnectHandler SetProperties failed. "
                 << "Error name: \"" << error_name << "\", "
                 << "Error data: " << error_data_ss.str();
}

std::string AutoConnectReasonsToString(int auto_connect_reasons) {
  std::string result;

  if (auto_connect_reasons &
      AutoConnectHandler::AutoConnectReason::AUTO_CONNECT_REASON_LOGGED_IN) {
    result += "Logged In";
  }

  if (auto_connect_reasons & AutoConnectHandler::AutoConnectReason::
                                 AUTO_CONNECT_REASON_POLICY_APPLIED) {
    if (!result.empty())
      result += ", ";
    result += "Policy Applied";
  }

  if (auto_connect_reasons & AutoConnectHandler::AutoConnectReason::
                                 AUTO_CONNECT_REASON_CERTIFICATE_RESOLVED) {
    if (!result.empty())
      result += ", ";
    result += "Certificate resolved";
  }

  return result;
}

}  // namespace

AutoConnectHandler::AutoConnectHandler()
    : client_cert_resolver_(nullptr),
      request_best_connection_pending_(false),
      device_policy_applied_(false),
      user_policy_applied_(false),
      client_certs_resolved_(false),
      applied_autoconnect_policy_(false),
      connect_to_best_services_after_scan_(false),
      auto_connect_reasons_(0),
      weak_ptr_factory_(this) {}

AutoConnectHandler::~AutoConnectHandler() {
  if (LoginState::IsInitialized())
    LoginState::Get()->RemoveObserver(this);
  if (client_cert_resolver_)
    client_cert_resolver_->RemoveObserver(this);
  if (network_connection_handler_)
    network_connection_handler_->RemoveObserver(this);
  if (network_state_handler_)
    network_state_handler_->RemoveObserver(this, FROM_HERE);
  if (managed_configuration_handler_)
    managed_configuration_handler_->RemoveObserver(this);
}

void AutoConnectHandler::Init(
    ClientCertResolver* client_cert_resolver,
    NetworkConnectionHandler* network_connection_handler,
    NetworkStateHandler* network_state_handler,
    ManagedNetworkConfigurationHandler* managed_network_configuration_handler) {
  if (LoginState::IsInitialized())
    LoginState::Get()->AddObserver(this);

  client_cert_resolver_ = client_cert_resolver;
  if (client_cert_resolver_)
    client_cert_resolver_->AddObserver(this);

  network_connection_handler_ = network_connection_handler;
  if (network_connection_handler_)
    network_connection_handler_->AddObserver(this);

  network_state_handler_ = network_state_handler;
  if (network_state_handler_)
    network_state_handler_->AddObserver(this, FROM_HERE);

  managed_configuration_handler_ = managed_network_configuration_handler;
  if (managed_configuration_handler_)
    managed_configuration_handler_->AddObserver(this);

  if (LoginState::IsInitialized())
    LoggedInStateChanged();
}

void AutoConnectHandler::LoggedInStateChanged() {
  if (!LoginState::Get()->IsUserLoggedIn())
    return;

  // Disconnect before connecting, to ensure that we do not disconnect a network
  // that we just connected.
  DisconnectIfPolicyRequires();
  RequestBestConnection(AutoConnectReason::AUTO_CONNECT_REASON_LOGGED_IN);
}

void AutoConnectHandler::ConnectToNetworkRequested(
    const std::string& /*service_path*/) {
  // Stop any pending request to connect to the best newtork.
  request_best_connection_pending_ = false;
}

void AutoConnectHandler::PoliciesApplied(const std::string& userhash) {
  if (userhash.empty()) {
    device_policy_applied_ = true;
  } else {
    user_policy_applied_ = true;
  }

  DisconnectIfPolicyRequires();

  // Request to connect to the best network only if there is at least one
  // managed network. Otherwise only process existing requests.
  const ManagedNetworkConfigurationHandler::GuidToPolicyMap* managed_networks =
      managed_configuration_handler_->GetNetworkConfigsFromPolicy(userhash);
  DCHECK(managed_networks);
  if (!managed_networks->empty()) {
    RequestBestConnection(
        AutoConnectReason::AUTO_CONNECT_REASON_POLICY_APPLIED);
  } else {
    CheckBestConnection();
  }
}

void AutoConnectHandler::ScanCompleted(const DeviceState* device) {
  if (!connect_to_best_services_after_scan_ ||
      device->type() != shill::kTypeWifi) {
    return;
  }
  connect_to_best_services_after_scan_ = false;
  // Request ConnectToBestServices after processing any pending DBus calls.
  base::ThreadTaskRunnerHandle::Get()->PostTask(
      FROM_HERE,
      base::BindOnce(&AutoConnectHandler::CallShillConnectToBestServices,
                     weak_ptr_factory_.GetWeakPtr()));
}

void AutoConnectHandler::ResolveRequestCompleted(
    bool network_properties_changed) {
  client_certs_resolved_ = true;

  // Only request to connect to the best network if network properties were
  // actually changed. Otherwise only process existing requests.
  if (network_properties_changed) {
    RequestBestConnection(
        AutoConnectReason::AUTO_CONNECT_REASON_CERTIFICATE_RESOLVED);
  } else {
    CheckBestConnection();
  }
}

void AutoConnectHandler::AddObserver(Observer* observer) {
  observer_list_.AddObserver(observer);
}

void AutoConnectHandler::RemoveObserver(Observer* observer) {
  observer_list_.RemoveObserver(observer);
}

void AutoConnectHandler::NotifyAutoConnectInitiatedForTest(
    int auto_connect_reasons) {
  NotifyAutoConnectInitiated(auto_connect_reasons);
}

void AutoConnectHandler::NotifyAutoConnectInitiated(int auto_connect_reasons) {
  for (auto& observer : observer_list_)
    observer.OnAutoConnectedInitiated(auto_connect_reasons);
}

void AutoConnectHandler::RequestBestConnection(
    AutoConnectReason auto_connect_reason) {
  request_best_connection_pending_ = true;
  auto_connect_reasons_ |= auto_connect_reason;
  CheckBestConnection();
}

void AutoConnectHandler::CheckBestConnection() {
  // Return immediately if there is currently no request pending to change to
  // the best network.
  if (!request_best_connection_pending_)
    return;

  bool policy_application_running =
      managed_configuration_handler_->IsAnyPolicyApplicationRunning();
  bool client_cert_resolve_task_running =
      client_cert_resolver_->IsAnyResolveTaskRunning();
  VLOG(2) << "device policy applied: " << device_policy_applied_
          << "\nuser policy applied: " << user_policy_applied_
          << "\npolicy application running: " << policy_application_running
          << "\nclient cert patterns resolved: " << client_certs_resolved_
          << "\nclient cert resolve task running: "
          << client_cert_resolve_task_running;
  if (!device_policy_applied_ || policy_application_running ||
      client_cert_resolve_task_running) {
    return;
  }

  if (LoginState::Get()->IsUserLoggedIn()) {
    // Before changing connection after login, we wait at least for:
    //  - user policy applied at least once
    //  - client certificate patterns resolved
    if (!user_policy_applied_ || !client_certs_resolved_)
      return;
  }

  request_best_connection_pending_ = false;

  // Trigger a ConnectToBestNetwork request after the next scan completion.
  // Note: there is an edge case here if a scan is in progress and a hidden
  // network has been configured since the scan started. crbug.com/433075.
  if (connect_to_best_services_after_scan_)
    return;
  connect_to_best_services_after_scan_ = true;
  if (!network_state_handler_->GetScanningByType(
          NetworkTypePattern::Primitive(shill::kTypeWifi))) {
    network_state_handler_->RequestScan(NetworkTypePattern::WiFi());
  }
}

void AutoConnectHandler::DisconnectIfPolicyRequires() {
  // Only block networks in a user session.
  if (!LoginState::Get()->IsUserLoggedIn())
    return;

  // Wait for both user and device policy to be applied before disconnecting.
  // The device policy holds the policies, which might cause the network to get
  // disconnected. The user policy might hold a valid network configuration,
  // which prevents the network from being disconnected.
  if (!user_policy_applied_ || !device_policy_applied_)
    return;

  const base::DictionaryValue* global_network_config =
      managed_configuration_handler_->GetGlobalConfigFromPolicy(
          std::string() /* no username hash, device policy */);
  if (!global_network_config)
    return;

  DisconnectAndRemoveBlacklistedNetworks();

  const base::Value* connect_value = global_network_config->FindKeyOfType(
      ::onc::global_network_config::kAllowOnlyPolicyNetworksToConnect,
      base::Value::Type::BOOLEAN);
  bool only_policy_connect = connect_value ? connect_value->GetBool() : false;

  const base::Value* autoconnect_value = global_network_config->FindKeyOfType(
      ::onc::global_network_config::kAllowOnlyPolicyNetworksToAutoconnect,
      base::Value::Type::BOOLEAN);
  bool only_policy_autoconnect =
      autoconnect_value ? autoconnect_value->GetBool() : false;

  // Reset |applied_autoconnect_policy_| if auto-connect policy is disabled.
  if (!only_policy_autoconnect)
    applied_autoconnect_policy_ = false;

  if (only_policy_connect) {
    // Disconnect and remove network configurations for all unmanaged networks.
    DisconnectFromAllUnmanagedWiFiNetworks(true, false);
  } else if (only_policy_autoconnect && !applied_autoconnect_policy_) {
    // Disconnect and disable auto-connect for all unmanaged networks.
    DisconnectFromAllUnmanagedWiFiNetworks(false, true);
    applied_autoconnect_policy_ = true;
  }
}

void AutoConnectHandler::DisconnectAndRemoveBlacklistedNetworks() {
  NET_LOG_DEBUG("DisconnectAndRemoveBlacklistedNetworks", "");

  const base::DictionaryValue* global_network_config =
      managed_configuration_handler_->GetGlobalConfigFromPolicy(
          std::string() /* no username hash, device policy */);

  const base::Value* blacklist_value = global_network_config->FindKeyOfType(
      ::onc::global_network_config::kBlacklistedHexSSIDs,
      base::Value::Type::LIST);
  if (!blacklist_value || blacklist_value->GetList().empty())
    return;  // No blacklisted WiFi networks set.

  std::set<std::string> blacklist;
  for (const base::Value& hex_ssid_value : blacklist_value->GetList())
    blacklist.insert(hex_ssid_value.GetString());

  NetworkStateHandler::NetworkStateList networks;
  network_state_handler_->GetNetworkListByType(NetworkTypePattern::WiFi(),
                                               false, false, 0, &networks);
  for (const NetworkState* network : networks) {
    if (blacklist.find(network->GetHexSsid()) == blacklist.end())
      continue;

    const bool is_managed =
        managed_configuration_handler_->FindPolicyByGuidAndProfile(
            network->guid(), network->profile_path(), nullptr /* onc_source */);
    if (is_managed)
      continue;

    if (network->IsConnectingOrConnected())
      DisconnectNetwork(network->path());

    if (network->IsInProfile())
      RemoveNetworkConfigurationForNetwork(network->path());
  }
}

void AutoConnectHandler::DisconnectFromAllUnmanagedWiFiNetworks(
    bool remove_configuration,
    bool disable_auto_connect) {
  NET_LOG_DEBUG("DisconnectFromAllUnmanagedWiFiNetworks", "");

  NetworkStateHandler::NetworkStateList networks;
  network_state_handler_->GetNetworkListByType(NetworkTypePattern::WiFi(),
                                               false, false, 0, &networks);
  for (const NetworkState* network : networks) {
    const bool is_managed =
        managed_configuration_handler_->FindPolicyByGuidAndProfile(
            network->guid(), network->profile_path(), nullptr /* onc_source */);
    if (is_managed)
      continue;

    if (network->IsConnectingOrConnected())
      DisconnectNetwork(network->path());

    if (network->IsInProfile()) {
      if (remove_configuration)
        RemoveNetworkConfigurationForNetwork(network->path());
      else if (disable_auto_connect)
        DisableAutoconnectForWiFiNetwork(network->path());
    }
  }
}

void AutoConnectHandler::DisconnectNetwork(const std::string& service_path) {
  NET_LOG_EVENT("Disconnect forced by policy", service_path);

  network_connection_handler_->DisconnectNetwork(
      service_path, base::DoNothing(),
      base::Bind(&DisconnectErrorCallback, service_path));
}

void AutoConnectHandler::RemoveNetworkConfigurationForNetwork(
    const std::string& service_path) {
  NET_LOG_EVENT("Remove configuration forced by policy", service_path);

  managed_configuration_handler_->RemoveConfiguration(
      service_path, base::DoNothing(),
      base::Bind(&RemoveNetworkConfigurationErrorCallback));
}

void AutoConnectHandler::DisableAutoconnectForWiFiNetwork(
    const std::string& service_path) {
  NET_LOG_EVENT("Disable auto-connect forced by policy", service_path);

  base::DictionaryValue properties;
  properties.SetPath({::onc::network_config::kWiFi, ::onc::wifi::kAutoConnect},
                     base::Value(false));
  managed_configuration_handler_->SetProperties(
      service_path, properties, base::DoNothing(),
      base::Bind(&SetPropertiesErrorCallback));
}

void AutoConnectHandler::CallShillConnectToBestServices() {
  NET_LOG(EVENT) << "ConnectToBestServices ["
                 << AutoConnectReasonsToString(auto_connect_reasons_) << "]";

  DBusThreadManager::Get()->GetShillManagerClient()->ConnectToBestServices(
      base::Bind(&AutoConnectHandler::NotifyAutoConnectInitiated,
                 weak_ptr_factory_.GetWeakPtr(), auto_connect_reasons_),
      base::Bind(&network_handler::ShillErrorCallbackFunction,
                 "ConnectToBestServices Failed", "",
                 network_handler::ErrorCallback()));
}

}  // namespace chromeos