Added Periodic reportingType support to Report

When report interval expires report will collect readings from
metrics and update timestamp.

Tested:
  - Added new units tests covering added code
  - All existing unit tests are passing

Change-Id: I7f23ca05d77efb0f18d2c0d0f138c524ffb4f6af
Signed-off-by: Krzysztof Grobelny <krzysztof.grobelny@intel.com>
diff --git a/src/interfaces/metric.hpp b/src/interfaces/metric.hpp
new file mode 100644
index 0000000..51fc8fa
--- /dev/null
+++ b/src/interfaces/metric.hpp
@@ -0,0 +1,18 @@
+#pragma once
+
+#include "metric_value.hpp"
+
+#include <vector>
+
+namespace interfaces
+{
+
+class Metric
+{
+  public:
+    virtual ~Metric() = default;
+
+    virtual const std::vector<MetricValue>& getReadings() const = 0;
+};
+
+} // namespace interfaces
diff --git a/src/interfaces/types.hpp b/src/interfaces/types.hpp
index 09a75cd..0d5eeb2 100644
--- a/src/interfaces/types.hpp
+++ b/src/interfaces/types.hpp
@@ -9,3 +9,7 @@
 using ReadingParameters =
     std::vector<std::tuple<std::vector<sdbusplus::message::object_path>,
                            std::string, std::string, std::string>>;
+
+using Readings = std::tuple<
+    uint64_t,
+    std::vector<std::tuple<std::string, std::string, double, uint64_t>>>;
diff --git a/src/metric.cpp b/src/metric.cpp
new file mode 100644
index 0000000..b40da5a
--- /dev/null
+++ b/src/metric.cpp
@@ -0,0 +1 @@
+#include "metric.hpp"
diff --git a/src/metric.hpp b/src/metric.hpp
new file mode 100644
index 0000000..a676e25
--- /dev/null
+++ b/src/metric.hpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "interfaces/metric.hpp"
+#include "interfaces/sensor_listener.hpp"
+
+class Metric : public interfaces::Metric, public interfaces::SensorListener
+{
+  public:
+    const std::vector<MetricValue>& getReadings() const override
+    {
+        return readings;
+    }
+
+    void sensorUpdated(interfaces::Sensor&, uint64_t) override
+    {}
+
+    void sensorUpdated(interfaces::Sensor&, uint64_t, double value) override
+    {}
+
+  private:
+    std::vector<MetricValue> readings;
+};
diff --git a/src/metric_value.hpp b/src/metric_value.hpp
new file mode 100644
index 0000000..d01ac4e
--- /dev/null
+++ b/src/metric_value.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+
+struct MetricValue
+{
+    std::string id;
+    std::string metadata;
+    double value;
+    uint64_t timestamp;
+};
diff --git a/src/report.cpp b/src/report.cpp
index 81e3b05..2e68d45 100644
--- a/src/report.cpp
+++ b/src/report.cpp
@@ -2,9 +2,7 @@
 
 #include "report_manager.hpp"
 
-using Readings = std::tuple<
-    uint64_t,
-    std::vector<std::tuple<std::string, std::string, double, uint64_t>>>;
+#include <numeric>
 
 Report::Report(boost::asio::io_context& ioc,
                const std::shared_ptr<sdbusplus::asio::object_server>& objServer,
@@ -13,9 +11,11 @@
                const bool logToMetricReportsCollection,
                const std::chrono::milliseconds period,
                const ReadingParameters& metricParams,
-               interfaces::ReportManager& reportManager) :
-    name{reportName},
-    path{reportDir + name}, interval{period}, objServer(objServer)
+               interfaces::ReportManager& reportManager,
+               std::vector<std::shared_ptr<interfaces::Metric>> metrics) :
+    name(reportName),
+    path(reportDir + name), interval(period), objServer(objServer),
+    metrics(std::move(metrics)), timer(ioc)
 {
     reportIface = objServer->add_unique_interface(
         path, reportIfaceName,
@@ -34,7 +34,10 @@
                     return true;
                 });
             dbusIface.register_property("Persistency", bool{false});
-            dbusIface.register_property("Readings", Readings{});
+            dbusIface.register_property_r(
+                "Readings", readings,
+                sdbusplus::vtable::property_::emits_change,
+                [this](const auto&) { return readings; });
             dbusIface.register_property("ReportingType", reportingType);
             dbusIface.register_property("ReadingParameters", metricParams);
             dbusIface.register_property("EmitsReadingsUpdate",
@@ -51,4 +54,52 @@
                 });
             });
         });
+
+    if (reportingType == "Periodic")
+    {
+        scheduleTimer(interval);
+    }
+}
+
+void Report::timerProc(boost::system::error_code ec, Report& self)
+{
+    if (ec)
+    {
+        return;
+    }
+
+    self.updateReadings();
+    self.scheduleTimer(self.interval);
+}
+
+void Report::scheduleTimer(std::chrono::milliseconds timerInterval)
+{
+    timer.expires_after(timerInterval);
+    timer.async_wait(
+        [this](boost::system::error_code ec) { timerProc(ec, *this); });
+}
+
+void Report::updateReadings()
+{
+    auto numElements = std::accumulate(
+        metrics.begin(), metrics.end(), 0u, [](auto sum, const auto& metric) {
+            return sum + metric->getReadings().size();
+        });
+
+    readingsCache.resize(numElements);
+
+    auto it = readingsCache.begin();
+
+    for (const auto& metric : metrics)
+    {
+        for (const auto& reading : metric->getReadings())
+        {
+            *(it++) = std::make_tuple(reading.id, reading.metadata,
+                                      reading.value, reading.timestamp);
+        }
+    }
+
+    std::get<0>(readings) = std::time(0);
+    std::get<1>(readings) = readingsCache;
+    reportIface->signal_property("Readings");
 }
diff --git a/src/report.hpp b/src/report.hpp
index fb40614..8cef26a 100644
--- a/src/report.hpp
+++ b/src/report.hpp
@@ -1,10 +1,12 @@
 #pragma once
 
+#include "interfaces/metric.hpp"
 #include "interfaces/report.hpp"
 #include "interfaces/report_manager.hpp"
 #include "interfaces/types.hpp"
 
 #include <boost/asio/io_context.hpp>
+#include <boost/asio/steady_timer.hpp>
 #include <sdbusplus/asio/object_server.hpp>
 
 #include <chrono>
@@ -20,12 +22,13 @@
            const bool logToMetricReportsCollection,
            const std::chrono::milliseconds period,
            const ReadingParameters& metricParams,
-           interfaces::ReportManager& reportManager);
+           interfaces::ReportManager& reportManager,
+           std::vector<std::shared_ptr<interfaces::Metric>> metrics);
     ~Report() = default;
 
-    Report(Report&) = delete;
+    Report(const Report&) = delete;
     Report(Report&&) = delete;
-    Report& operator=(Report&) = delete;
+    Report& operator=(const Report&) = delete;
     Report& operator=(Report&&) = delete;
 
     std::string getName() const override
@@ -39,12 +42,20 @@
     }
 
   private:
+    static void timerProc(boost::system::error_code, Report& self);
+    void scheduleTimer(std::chrono::milliseconds interval);
+    void updateReadings();
+
     const std::string name;
     const std::string path;
     std::chrono::milliseconds interval;
+    Readings readings = {};
+    std::tuple_element_t<1, Readings> readingsCache = {};
     std::shared_ptr<sdbusplus::asio::object_server> objServer;
     std::unique_ptr<sdbusplus::asio::dbus_interface> reportIface;
     std::unique_ptr<sdbusplus::asio::dbus_interface> deleteIface;
+    std::vector<std::shared_ptr<interfaces::Metric>> metrics;
+    boost::asio::steady_timer timer;
 
   public:
     static constexpr const char* reportIfaceName =
diff --git a/src/report_factory.cpp b/src/report_factory.cpp
index 9f51db5..27e4ee7 100644
--- a/src/report_factory.cpp
+++ b/src/report_factory.cpp
@@ -15,7 +15,10 @@
     std::chrono::milliseconds period, const ReadingParameters& metricParams,
     interfaces::ReportManager& reportManager) const
 {
+    std::vector<std::shared_ptr<interfaces::Metric>> metrics;
+
     return std::make_unique<Report>(
         ioc, objServer, name, reportingType, emitsReadingsSignal,
-        logToMetricReportsCollection, period, metricParams, reportManager);
+        logToMetricReportsCollection, period, metricParams, reportManager,
+        std::move(metrics));
 }