server-sdk/src/serversdk/databasetable.h

#pragma once

#include <QObject>
#include <QVariantMap>
#include <QSet>

#include <memory>


#define TABLE_PROPERTY(TYPE, NAME, SETNAME, INITVAL) \
    Q_PROPERTY(TYPE NAME READ NAME WRITE SETNAME NOTIFY NAME ## Changed USER true) \
    public: \
       TYPE NAME() const { return a_ ## NAME ; } \
       Q_SLOT void SETNAME(const TYPE &value) { \
          if (a_ ## NAME == value)  return; \
          a_ ## NAME = value; \
          emit NAME ## Changed(value); \
        } \
       Q_SIGNAL void NAME ## Changed(TYPE value);\
    private: \
       TYPE a_ ## NAME = INITVAL;

namespace serversdk {

// Default TABLE_PROPERTY
/** # DatabaseTable
 *
 *  Class for automatic CREATE/INSERT/SELECT and JSON handling
 *
 *  ## Usage
 *
 * 1. define custom class by subclassint serversdk::DatabaseTable
 *
 * @code
   class Names : public serversdk::DatabaseTable {
        Q_OBJECT
        TABLE_PROPERTY(int, id, set_id, 0);
        TABLE_PROPERTY(QString, name, set_name, 0);
   };

   int main() {
      // Prepare temporary path for database
      QTemporaryDir dir;
      QString dbpath = dir.path() + "/testdb.sqlite";
      serversdk::DatabaseManager db;
      db.openSQLite(dbpath);


      Names names;

      // CREATE TABLE
      serversdk::DatabaseUtils utils(&db);
      QSqlQuery query = utils.createTable(&names, "names");

      // INSERT INTO TABLE
      names.set_id(2);
      names.set_name("Testname");

      utils.insertIntoTable(&names, "names");

      // SELECT FROM TABLE
      QSqlQuery selectSQL = db.execPlainSql("SELECT * FROM names");
      auto list = utils.tableFromQuery<Names>(selectSQL);
   }
 *
 * @endcode
 *
 * ## Warning
 *
 * Derivation of derived class from DatabaseTable does not work ( missing properties )
 *
 * @code
 *  in: TABLE_PROPERTY
 *  Q_PROPERTY
 * @endcode
 *
 *
 *
 *
 */
class DatabaseTable : public QObject
{
    Q_OBJECT
public:
    explicit DatabaseTable(QObject *parent = nullptr);

    QString primaryKey() const;

    /**
     * @brief Creates JSON from QMetaObject data ( Q_PROPERTY ) -> TABLE_PROPERTY
     * @return text json e.g. { "id": 00344 }
     */
    virtual QByteArray jsonData(const QSet<QString> &filters = {}) const;

    /**
     * @brief Populates object with JSON {"id": 300} )
     * @return true if success TODO: not implemented corrrectly
     */
    virtual bool fromJson(const QByteArray &data);

    /**
     * @brief Creates VariantMap from QMetaObject data ( Q_PROPERTY )
     * @return QVariantMap containing property with key/value pairs
     */
    virtual QVariantMap toVariantMap(const QSet<QString> &filters = {}) const;


    /**
     * @brief Populates object with QVariantMap
     * @return true if success TODO: not implemented corrrectly
     */

    bool fromVariantMap(const QVariantMap &variantMap);


    /**
     * @brief Creates QList of objects from SELECT query
     * @param rows with QVariantMap ( rows of key/value pairs )
     * @return List of objects
     */
    static QList<std::shared_ptr<DatabaseTable>> fromListVariantMap(const QList<QVariantMap> &listMap);

    /**
     * @brief Convert QVariant type to SQL type
     * @param QVariant type ( QString, int, QDateTime )
     * @return text form of database type ( INTEGER, TEXT )
     */
    virtual QString textSQLIteType(QVariant::Type type) const;

    /**
     * @brief Convert QVariant type to SQL type
     * @param QVariant type ( QString, int, QDateTime )
     * @return text form of database type ( INTEGER, TEXT )
     *
     * # Sublassing
     *
     * When it is neccessary to use different type it is possible to subclass and override this method.
     *
     * @code
        class BackendTable : public serversdk::DatabaseTable
        {
          QString textPostgresType(QVariant::Type type) const override;
        }

        BackendTable::textPostgresType(QVariant::Type type) const override
        {
            // For case when saving date time as ms since epoch
            if (type == QVariant::DateTime) {
                return QStringLiteral("INTEGER");
            }
            return DatabaseTable::textPostgresType(type);
        }

     * @endcode
     *
     *
     *
     *
     */
    virtual QString textPostgresType(QVariant::Type type) const;

};


} // namespace serversdk