Progress #19: Initial work on PurchaseWrapper

Begin implementation of PurchaseWrapper, which wraps CapnP Purchase
APIs. Complete notification is done, still to do is getting prces,
notifying server of payment

StubBackend/PurchaseImpl.cpp

@@ -64,6 +64,7 @@ ::kj::Promise<void> PurchaseImpl::paymentSent(Purchase::Server::PaymentSentConte
 void PurchaseImpl::sendNotification()
 {
     KJ_IF_MAYBE(notifier, completionNotifier) {
+        notifier->notifyRequest().setMessage("true");
         notifier->notifyRequest().send();
     }
 }

StubBackend/PurchaseImpl.hpp

@@ -52,6 +52,6 @@ class PurchaseImpl : public Purchase::Server
 
     bool isComplete = false;
     QMap<QString, QList<Price>> promosAndPrices;
-    kj::Maybe<Notifier<capnp::AnyPointer>::Client> completionNotifier;
+    kj::Maybe<Notifier<capnp::Text>::Client> completionNotifier;
     std::function<void()> callback;
 };

VotingApp/VotingApp.qbs

@@ -48,6 +48,8 @@ QtGuiApplication {
         "wrappers/Converters.hpp",
         "wrappers/PurchaseContestRequest.cpp",
         "wrappers/PurchaseContestRequest.hpp",
+        "wrappers/PurchaseWrapper.cpp",
+        "wrappers/PurchaseWrapper.hpp",
         "wrappers/README.md",
         "qml-promise/src/Promise.cpp",
         "qml-promise/src/Promise.hpp",

VotingApp/main.cpp

@@ -34,6 +34,7 @@
 #include "wrappers/Datagram.hpp"
 #include "wrappers/ContestGeneratorWrapper.hpp"
 #include "wrappers/PurchaseContestRequest.hpp"
+#include "wrappers/PurchaseWrapper.hpp"
 #include "wrappers/ContestCreator.hpp"
 #include "wrappers/BackendWrapper.hpp"
 #include "wrappers/ChainAdaptorWrapper.hpp"
@@ -71,6 +72,7 @@ int main(int argc, char *argv[])
     REGISTER_WRAPPER(ContestGenerator);
     REGISTER_WRAPPER(ContestCreator);
     REGISTER_WRAPPER(PurchaseContestRequest);
+    REGISTER_WRAPPER(Purchase);
 #undef REGISTER_WRAPPER
 
     // Register enum wrappers

VotingApp/wrappers/PurchaseContestRequest.cpp

@@ -1,4 +1,5 @@
 #include "PurchaseContestRequest.hpp"
+#include "PurchaseWrapper.hpp"
 #include "Converters.hpp"
 
 #include <PromiseConverter.hpp>
@@ -62,7 +63,8 @@ PurchaseContestRequestWrapper::PurchaseContestRequestWrapper(PurchaseRequest&& r
                                                              QObject* parent)
     : QObject(parent),
       tasks(taskTracker),
-      request(kj::mv(request))
+      request(kj::mv(request)),
+      converter(tasks)
 {
     // When the contestants change, automatically update the request
     connect(&m_contestants, &QQmlVariantListModel::dataChanged,
@@ -83,7 +85,6 @@ bool PurchaseContestRequestWrapper::sponsorshipEnabled() const {
 QVariantMap PurchaseContestRequestWrapper::submit() {
     auto promise = request.send();
     auto purchase = promise.getPurchaseApi();
-    PromiseConverter converter(tasks);
     auto qmlPromise = converter.convert(kj::mv(promise),
                                         [] (capnp::Response<ContestCreator::PurchaseContestResults> r) -> QVariantList
     {
@@ -94,8 +95,8 @@ QVariantMap PurchaseContestRequestWrapper::submit() {
         return QVariantList() << results;
     });
 
-    // TODO: Replace 'false' below with the wrapped purchase API
-    return QVariantMap{{"purchaseApi", false},{"surchargePromise", QVariant::fromValue(qmlPromise)}};
+    return QVariantMap{{"purchaseApi", QVariant::fromValue(new PurchaseWrapper(kj::mv(purchase), tasks, this))},
+                       {"surchargePromise", QVariant::fromValue(qmlPromise)}};
 }
 
 void PurchaseContestRequestWrapper::disableSponsorship() {

VotingApp/wrappers/PurchaseContestRequest.hpp

@@ -3,6 +3,7 @@
 
 #include <QObject>
 
+#include <PromiseConverter.hpp>
 #include <contestcreator.capnp.h>
 
 #include "vendor/QQmlEnumClassHelper.h"
@@ -48,6 +49,8 @@ class PurchaseContestRequestWrapper : public QObject
     kj::TaskSet& tasks;
     QQmlVariantListModel m_contestants;
     QQmlVariantListModel m_promoCodes;
+    PromiseConverter converter;
+
 public:
     using PurchaseRequest = capnp::Request<::ContestCreator::PurchaseContestParams,
                                            ::ContestCreator::PurchaseContestResults>;

VotingApp/wrappers/PurchaseWrapper.cpp

@@ -0,0 +1,40 @@
+#include "PurchaseWrapper.hpp"
+
+namespace swv {
+
+void PurchaseWrapper::setComplete(bool complete)
+{
+    if (complete == m_complete) return;
+    m_complete = complete;
+    emit completeChanged(complete);
+}
+
+PurchaseWrapper::PurchaseWrapper(Purchase::Client&& api, kj::TaskSet& tasks, QObject *parent)
+    : QObject(parent),
+      api(kj::mv(api)),
+      tasks(tasks),
+      converter(tasks)
+{
+    class CompleteNotifier : public Notifier<capnp::Text>::Server {
+        PurchaseWrapper& wrapper;
+        virtual ::kj::Promise<void> notify(NotifyContext context) {
+            wrapper.setComplete(context.getParams().getMessage() == "true");
+            return kj::READY_NOW;
+        }
+
+    public:
+        CompleteNotifier(PurchaseWrapper& wrapper) : wrapper(wrapper) {}
+    };
+
+    auto request = api.subscribeRequest();
+    request.setNotifier(kj::heap<CompleteNotifier>(*this));
+    tasks.add(request.send().then([](capnp::Response<Purchase::SubscribeResults>){}));
+    tasks.add(api.completeRequest().send().then([this] (capnp::Response<Purchase::CompleteResults> r) {
+                  setComplete(r.getResult());
+              }));
+}
+
+PurchaseWrapper::~PurchaseWrapper() noexcept
+{}
+
+} // namespace swv

VotingApp/wrappers/PurchaseWrapper.hpp

@@ -0,0 +1,42 @@
+#ifndef PURCHASEWRAPPER_HPP
+#define PURCHASEWRAPPER_HPP
+
+#include <purchase.capnp.h>
+#include <PromiseConverter.hpp>
+
+#include <QObject>
+
+namespace swv {
+
+/**
+ * @brief The PurchaseWrapper class provides a QML-friendly interface to the CapnP Purchase type
+ *
+ * PurchaseWrapper subscribes to a push notification from the server when the purchase is complete, so the complete
+ * property will be updated automatically as soon as the purchase completes.
+ */
+class PurchaseWrapper : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(bool complete READ complete NOTIFY completeChanged)
+
+    Purchase::Client api;
+    kj::TaskSet& tasks;
+    PromiseConverter converter;
+    bool m_complete = false;
+
+    void setComplete(bool complete);
+
+public:
+    explicit PurchaseWrapper(Purchase::Client&& api, kj::TaskSet& tasks, QObject *parent = 0);
+    virtual ~PurchaseWrapper() noexcept;
+
+    bool complete() const {
+        return m_complete;
+    }
+
+signals:
+    void completeChanged(bool complete);
+};
+
+} // namespace swv
+#endif // PURCHASEWRAPPER_HPP

shared/capnp/purchase.capnp

@@ -26,8 +26,8 @@ interface Purchase {
     # Check the status of the purchase
     prices @1 (promoCode :Text) -> (prices :List(Price));
     # Get the price of the purchase in all available coins
-    subscribe @2 (notifier :Notifier) -> ();
-    # Get notified when the purchase is complete
+    subscribe @2 (notifier :Notifier(Text)) -> ();
+    # Get notified when the purchase is complete. Notification message will either be "true" or "false"
     paymentSent @3 (priceSelection :Price) -> ();
     # Used to notify the server that the payment has been sent