Cashew: implement backend usage API

src/service.cc

Index: src/service.cc
diff --git a/src/service.cc b/src/service.cc
index a05f431705f3f92e7c81bf2e96d7eff053f5ab22..e2562ee7322f2b6ae8d0a41b63ad53f1278c2695 100644
--- a/src/service.cc
+++ b/src/service.cc
@@ -6,52 +6,70 @@
 
 #include <glog/logging.h>
 
+#include "src/data_plan_provider.h"
 #include "src/device.h"
+#include "src/policy.h"
+#include "src/service_manager.h"
 
 namespace cashew {
 
 // Flimflam Service D-Bus identifiers
-static const char* kFlimflamServiceName = "org.chromium.flimflam";
+static const char *kFlimflamServiceName = "org.chromium.flimflam";
 
 // Flimflam Service property names
 static const char *kFlimflamServiceDeviceProperty = "Device";
 static const char *kFlimflamServiceStateProperty = "State";
-static const char* kFlimflamServiceTypeProperty = "Type";
+static const char *kFlimflamServiceTypeProperty = "Type";
+static const char *kFlimflamServiceUsageUrlProperty = "Cellular.UsageUrl";
 
 // Flimflam Service on-the-wire State values
-static const char* kFlimflamServiceStateIdle = "idle";
-static const char* kFlimflamServiceStateCarrier = "carrier";
-static const char* kFlimflamServiceStateAssociation = "association";
-static const char* kFlimflamServiceStateConfiguration = "configuration";
-static const char* kFlimflamServiceStateReady = "ready";
-static const char* kFlimflamServiceStateDisconnect = "disconnect";
-static const char* kFlimflamServiceStateFailure = "failure";
-static const char* kFlimflamServiceStateActivationFailure =
+static const char *kFlimflamServiceStateIdle = "idle";
+static const char *kFlimflamServiceStateCarrier = "carrier";
+static const char *kFlimflamServiceStateAssociation = "association";
+static const char *kFlimflamServiceStateConfiguration = "configuration";
+static const char *kFlimflamServiceStateReady = "ready";
+static const char *kFlimflamServiceStateDisconnect = "disconnect";
+static const char *kFlimflamServiceStateFailure = "failure";
+static const char *kFlimflamServiceStateActivationFailure =
     "activation-failure";
 
 // Flimflam Service on-the-wire Type values
-static const char* kFlimflamServiceTypeEthernet = "ethernet";
-static const char* kFlimflamServiceTypeWifi = "wifi";
-static const char* kFlimflamServiceTypeWimax = "wimax";
-static const char* kFlimflamServiceTypeBluetooth = "bluetooth";
-static const char* kFlimflamServiceTypeCellular = "cellular";
-
-Service::Service(DBus::Connection& connection,  // NOLINT
+static const char *kFlimflamServiceTypeEthernet = "ethernet";
+static const char *kFlimflamServiceTypeWifi = "wifi";
+static const char *kFlimflamServiceTypeWimax = "wimax";
+static const char *kFlimflamServiceTypeBluetooth = "bluetooth";
+static const char *kFlimflamServiceTypeCellular = "cellular";
+
+// Chromium OS Usage API property names
+static const char *kCrosUsageVersionProperty = "version";
+static const char *kCrosUsageStatusProperty = "status";
+static const char *kCrosUsageRestrictedProperty = "restricted";
+static const char *kCrosUsagePlansProperty = "plans";
+
+// Chromium OS Usage API version values
+static const int kCrosUsageVersionMinSupported = 1;
+static const int kCrosUsageVersionMaxSupported = 1;
+
+// Chromium OS Usage API status values
+static const char *kCrosUsageStatusOk = "OK";
+static const char *kCrosUsageStatusError = "ERROR";
+
+Service::Service(ServiceManager * const parent,
+                 DBus::Connection& connection,  // NOLINT
                  const DBus::Path& path)
     : DBus::ObjectProxy(connection, path, kFlimflamServiceName),
-      connection_(connection), path_(path), state_(kStateUnknown),
-      type_(kTypeUnknown), device_(NULL) {
+      parent_(CHECK_NOTNULL(parent)), connection_(connection), path_(path),
+      state_(kStateUnknown), type_(kTypeUnknown), device_(NULL),
+      provider_(NULL), request_in_progress_(false),
+      update_timeout_source_(NULL), policy_(NULL) {
   // init our state with a GetProperties() call to our Flimflam service path
   // we'll update this state by monitoring PropertyChanged signals
   GetServiceProperties();
-
-  // init our data plans list with a hardcoded plan
-  // TODO(vlaviano): implement backend and return real data
-  AddHardcodedDataPlan();
 }
 
 Service::~Service() {
-  DeleteDataPlans();
+  DeleteCarrierState();
+  DeleteDataPlans(&data_plans_);
   if (device_ != NULL) {
     DLOG(INFO) << path_ << ": deleting device " << device_->GetPath();
     delete device_;
@@ -97,11 +115,172 @@ void Service::PropertyChanged(const std::string& property_name,
     OnStateUpdate(new_value.reader().get_string());
   } else if (property_name.compare(kFlimflamServiceTypeProperty) == 0) {
     OnTypeUpdate(new_value.reader().get_string());
+  } else if (property_name.compare(kFlimflamServiceUsageUrlProperty) == 0) {
+    OnUsageUrlUpdate(new_value.reader().get_string());
   } else {
     // we don't care about this property
   }
 }
 
+// Device methods
+
+void Service::OnCarrierUpdate(const std::string& carrier) {
+  DLOG(INFO) << path_ << ": OnCarrierUpdate: carrier = " << carrier;
+  // NOTE: device_ can be NULL here because we may still be in Device ctor
+  DCHECK(device_ == NULL || carrier.compare(device_->GetCarrier()) == 0);
+
+  // get rid of state associated with old carrier
+  if (provider_ != NULL) {
+    DCHECK(carrier.compare(provider_->GetCarrier()));
+  }
+  DeleteCarrierState();
+
+  // if we don't have new carrier info, we can't do anything now
+  if (carrier.compare(Device::kCarrierUnknown) == 0) {
+    return;
+  }
+
+  // create state for new carrier
+  DLOG(INFO) << path_ << ": OnCarrierUpdate: creating data plan provider";
+  provider_ = new(std::nothrow) DataPlanProvider(carrier);
+  if (provider_ == NULL) {
+    LOG(ERROR) << path_
+        << ": OnCarrierUpdate: could not create data plan provider";
+    return;
+  }
+  provider_->SetDelegate(this);
+  DLOG(INFO) << path_ << ": OnCarrierUpdate: getting policy for " << carrier;
+  policy_ = Policy::GetPolicy(carrier);
+  if (policy_ == NULL) {
+    LOG(ERROR) << path_ << ": OnCarrierUpdate: could not get policy for "
+        << carrier;
+    DeleteCarrierState();
+    return;
+  }
+
+  // if we already have usage url, set new provider in motion
+  if (!usage_url_.empty()) {
+    provider_->SetUsageUrl(usage_url_);
+    RequestUsageUpdate();
+    CreateUpdateTimer();
+  } else {
+    // we'll do this later in OnUsageUrlUpdate
+  }
+}
+
+// DataPlanProviderDelegate methods
+
+void Service::OnRequestComplete(const DataPlanProvider *provider,
+                                bool successful,
+                                const Value *parsed_usage_update) {
+  DCHECK(provider != NULL);
+  DCHECK(!successful || parsed_usage_update != NULL);
+  if (provider != provider_) {
+    DLOG(WARNING) <<  path_ << ": OnRequestComplete: wrong provider";
+    return;
+  }
+  DCHECK(request_in_progress_);
+  DCHECK(policy_ != NULL);
+  DLOG(INFO) << path_ << ": OnRequestComplete: result = " << successful;
+  request_in_progress_ = false;
+  if (!successful) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: request failed";
+    return;
+  }
+
+  // interpret and validate parsed usage update
+  if (!parsed_usage_update->IsType(Value::TYPE_DICTIONARY)) {
+    LOG(WARNING) << path_
+        << ": OnRequestComplete: root value is not a dictionary";
+    return;
+  }
+  const DictionaryValue *root =
+      static_cast<const DictionaryValue*>(parsed_usage_update);
+
+  int version;
+  if (!root->GetInteger(kCrosUsageVersionProperty, &version)) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: no version property";
+    return;
+  }
+  DLOG(INFO) << path_ << ": OnRequestComplete: version = " << version;
+  if (version < kCrosUsageVersionMinSupported ||
+      version > kCrosUsageVersionMaxSupported) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: version " << version
+        << " not in supported range of [" << kCrosUsageVersionMinSupported
+        << ", " << kCrosUsageVersionMaxSupported << "]";
+    return;
+  }
+
+  std::string status;
+  if (!root->GetString(kCrosUsageStatusProperty, &status)) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: no status property";
+    return;
+  }
+  DLOG(INFO) << path_ << ": OnRequestComplete: status = " << status;
+  if (status != kCrosUsageStatusOk && status != kCrosUsageStatusError) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: invalid status: " << status;
+    return;
+  }
+  if (status == kCrosUsageStatusError) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: status: " << status;
+    return;
+  }
+
+  bool restricted = false;
+  if (root->GetBoolean(kCrosUsageRestrictedProperty, &restricted)) {
+    DLOG(INFO) << path_ << ": OnRequestComplete: restricted = " << restricted;
+  } else {
+    DLOG(INFO) << path_ << ": OnRequestComplete: no restricted property";
+    // restricted property is optional
+  }
+
+  ListValue *plans = NULL;  // list to which this points is owned by dictionary
+  if (!root->GetList(kCrosUsagePlansProperty, &plans)) {
+    LOG(WARNING) << path_ << ": OnRequestComplete: no plans property";
+    return;
+  }
+  DCHECK(plans != NULL);
+  size_t plans_size = plans->GetSize();
+  DLOG(INFO) << path_ << ": OnRequestComplete: plans list has size "
+    << plans_size;
+
+  // walk plans list and convert each into a DataPlan object
+  DataPlanList new_plans;
+  for (size_t i = 0; i < plans_size; ++i) {
+    DictionaryValue *plan_dict = NULL;
+    if (!plans->GetDictionary(i, &plan_dict)) {
+      LOG(WARNING) << path_
+          << ": OnRequestComplete: could not get plan[" << i << "]";
+      continue;
+    }
+    DCHECK(plan_dict != NULL);
+    DataPlan *plan = DataPlan::FromDictionaryValue(plan_dict);
+    if (plan == NULL) {
+      LOG(WARNING) << path_
+          << ": OnRequestComplete: could not convert plan[" << i << "]";
+      continue;
+    }
+    DLOG(INFO) << path_ << ": OnRequestComplete: converted plan[" << i << "]";
+    new_plans.push_back(plan);
+  }
+
+  // store new info, causing it to be used for subsequent updates to clients
+  DataPlanList old_plans = data_plans_;
+  data_plans_ = new_plans;
+  LOG(INFO) << path_ << ": OnRequestComplete: updated data plans";
+
+  // consult policy to determine if we should send an unsolicited update
+  if (policy_->ShouldEmitDataPlansUpdate(old_plans, new_plans)) {
+    DLOG(INFO) << path_ << ": OnRequestComplete: sending update";
+    parent_->EmitDataPlansUpdate(*this);
+  } else {
+    DLOG(INFO) << path_ << ": OnRequestComplete: not sending update";
+  }
+
+  DLOG(INFO) << path_ << ": OnRequestComplete: deleting old data plans";
+  DeleteDataPlans(&old_plans);
+}
+
 // Private methods
 
 Service::State Service::StateFromString(const std::string& state) const {
@@ -169,7 +348,7 @@ void Service::OnDeviceUpdate(const DBus::Path& device_path) {
   }
 
   // if there's no existing device: make one
-  device_ = new(std::nothrow) Device(connection_, device_path);
+  device_ = new(std::nothrow) Device(this, connection_, device_path);
   if (device_ == NULL) {
     LOG(ERROR) << path_ << ": OnDeviceUpdate: couldn't create device for "
         << device_path;
@@ -194,6 +373,22 @@ void Service::OnTypeUpdate(const std::string& type) {
   }
 }
 
+void Service::OnUsageUrlUpdate(const std::string& usage_url) {
+  DLOG(INFO) << path_ << ": OnUsageUrlUpdate: url = " << usage_url;
+  if (usage_url.compare(usage_url_) == 0) {
+    return;
+  }
+  usage_url_ = usage_url;
+  if (provider_ != NULL) {
+    DCHECK(usage_url.compare(provider_->GetUsageUrl()));
+    DestroyUpdateTimer();
+    CancelPendingRequests();
+    provider_->SetUsageUrl(usage_url);
+    RequestUsageUpdate();
+    CreateUpdateTimer();
+  }
+}
+
 void Service::GetServiceProperties() {
   DLOG(INFO) << path_ << ": GetServiceProperties";
   PropertyMap properties;
@@ -240,16 +435,29 @@ void Service::GetServiceProperties() {
   } else {
     DLOG(WARNING) << path_ << ": GetServiceProperties: no Type property";
   }
+  // don't expect to find Cellular.* properties if we're not a cellular service
+  if (type_ != kTypeCellular) {
+    return;
+  }
+  it = properties.find(kFlimflamServiceUsageUrlProperty);
+  if (it != properties.end()) {
+    const DBus::Variant& value = static_cast<DBus::Variant>(it->second);
+    OnUsageUrlUpdate(value.reader().get_string());
+  } else {
+    DLOG(WARNING) << path_
+        << ": GetServiceProperties: no Cellular.UsageUrl property";
+  }
 }
 
-void Service::DeleteDataPlans() {
-  while (!data_plans_.empty()) {
-    DataPlan *plan = *data_plans_.begin();
+void Service::DeleteDataPlans(DataPlanList *data_plans) {
+  DCHECK(data_plans != NULL);
+  while (!data_plans->empty()) {
+    DataPlan *plan = *data_plans->begin();
     DCHECK(plan != NULL);
     DLOG(INFO) << path_ << ": DeleteDataPlans: deleting plan: "
         << plan->GetName();
     delete plan;
-    data_plans_.erase(data_plans_.begin());
+    data_plans->erase(data_plans->begin());
   }
 }
 
@@ -274,4 +482,90 @@ void Service::AddHardcodedDataPlan() {
   data_plans_.push_back(plan);
 }
 
+void Service::RequestUsageUpdate() {
+  DCHECK(provider_ != NULL);
+  DCHECK(!usage_url_.empty());
+  DCHECK(device_ == NULL ||
+         device_->GetCarrier().compare(Device::kCarrierUnknown));
+
+  if (request_in_progress_) {
+    return;
+  }
+
+  // TODO(vlaviano): apply policy to determine if current connectivity state
+  // allows this request (e.g., if we can only make API requests over the
+  // cellular service itself, is this service the default route?)
+
+  if (!provider_->RequestUsageUpdate()) {
+    DLOG(WARNING) << path_ << ": RequestUsageUpdate: request failed";
+  } else {
+    DLOG(INFO) << path_ << ": RequestUsageUpdate: request succeeded";
+    request_in_progress_ = true;
+  }
+}
+
+void Service::CancelPendingRequests() {
+  if (provider_ != NULL && request_in_progress_) {
+    provider_->CancelPendingRequests();
+    request_in_progress_ = false;
+  }
+}
+
+gboolean Service::UpdateTimeoutCallback() {
+  DLOG(INFO) << path_ << ": UpdateTimeoutCallback";
+  RequestUsageUpdate();
+  return TRUE;
+}
+
+// static
+gboolean Service::StaticUpdateTimeoutCallback(gpointer data) {
+  CHECK_NOTNULL(data);
+  return reinterpret_cast<Service*>(data)->UpdateTimeoutCallback();
+}
+
+bool Service::CreateUpdateTimer() {
+  DCHECK(provider_ != NULL);
+  DCHECK(policy_ != NULL);
+  guint idle_seconds = policy_->GetUpdateTimerIdleSecs(data_plans_);
+  DLOG(INFO) << path_ << ": CreateUpdateTimer: idle_seconds = " << idle_seconds;
+  if (update_timeout_source_ != NULL) {
+    DLOG(WARNING) << path_ << ": CreateUpdateTimer: timer already running";
+    return false;
+  }
+  update_timeout_source_ = g_timeout_source_new_seconds(idle_seconds);
+  if (update_timeout_source_ == NULL) {
+    DLOG(WARNING) << path_
+        << ": CreateUpdateTimer: could not create timeout source";
+    return false;
+  }
+  g_source_set_callback(update_timeout_source_, StaticUpdateTimeoutCallback,
+                        this, NULL);
+  g_source_attach(update_timeout_source_, NULL);
+  return true;
+}
+
+void Service::DestroyUpdateTimer() {
+  DLOG(INFO) << path_ << ": DestroyUpdateTimer";
+  if (update_timeout_source_ != NULL) {
+    g_source_destroy(update_timeout_source_);
+    update_timeout_source_ = NULL;
+  }
+}
+
+void Service::DeleteCarrierState() {
+  DLOG(INFO) << path_ << ": DeleteCarrierState";
+  if (policy_ != NULL) {
+    DLOG(INFO) << path_ << ": DeleteCarrierState: deleting policy";
+    delete policy_;
+    policy_ = NULL;
+  }
+  DestroyUpdateTimer();
+  CancelPendingRequests();
+  if (provider_ != NULL) {
+    DLOG(INFO) << path_ << ": DeleteCarrierState: deleting data plan provider";
+    delete provider_;
+    provider_ = NULL;
+  }
+}
+
 }  // namespace cashew