Rewrite electricity-logger to use an sqlite3 database

include/solar/logger/database.hpp

@@ -0,0 +1,25 @@
+#pragma once
+#include <cstdint>
+#include <sqlite3.h>
+#include <string>
+
+struct Row
+{
+    time_t epochTime;
+    std::int32_t watt;
+    double kilowattPerHour;
+};
+
+class Database {
+private:
+    sqlite3 * connectionPtr;
+
+    std::string ToSqlInsertStatement(Row const & row) const;
+    std::string ToSqlUpsertStatement(Row const & row) const;
+
+public:
+    bool Insert(Row & row);
+
+    Database(std::string const & databasePath);
+    ~Database();
+};

include/solar/logger/zeverdata.hpp

@@ -0,0 +1,33 @@
+#pragma once
+#include <cstdio>
+#include <ctime>
+#include <curl/curl.h> // tested with libcurl4-openSSH
+#include <sstream>
+#include <string>
+
+/*
+	This class holds all the data retrieved from the Zeverlution combox /
+	Zeverlution Sxxxx smart inverters / ZeverSolar box.
+
+	For output formatting it uses a timestamp to log the datetime alongside the
+	watts and kilowatts.
+*/
+
+struct ZeverData
+{
+    int number0, number1;
+    std::string registeryID, registeryKey, hardwareVersion, appVersion, wifiVersion;
+    std::string timeValue, dateValue, zeverCloudStatus;
+    int number3;
+    std::string inverterSN;
+    int watt;
+    double kilowattPerHour;
+    std::string OKmsg, ERRORmsg;
+
+    // Parses the data string coming from the zeverlution home.cgi webpage
+    bool ParseString(const std::string & str);
+
+    bool FetchDataFromURL(const std::string & url, const unsigned int timeout);
+
+    ZeverData();
+};