#ifndef OBELISK_KNOWLEDGE_BASE_H
#define OBELISK_KNOWLEDGE_BASE_H

#include <sqlite3.h>

#include <functional>
#include <iostream>
#include <string>

namespace obelisk
{
    class KnowledgeBase
    {
        private:
            const int DEFAULT_FLAGS
                = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
            const char* filename_;
            sqlite3* dbConnection_ = nullptr;
            int flags_;
            void logSqliteError(int result);

            void createTable(std::function<const char*()> function);

        public:
            KnowledgeBase(const char* filename);
            KnowledgeBase(const char* filename, int flags);
            ~KnowledgeBase();

            template<typename T, typename U>
            int addFacts(std::string verb, T leftEntities, U rightEntities);
            // TODO: add parameter for fact
            template<typename T, typename U>
            int addRules(std::string verb, T leftEntities, U rightEntities);
            template<typename T, typename U> int addActions();

            void getDouble(double& result, float var1, float var2);
            void getFloat(float& result1, float& result2, double var);
    };

    class KnowledgeBaseException : public std::exception
    {
        private:
            const std::string errorMessage_;

        public:
            KnowledgeBaseException() :
                errorMessage_("an unknown error ocurred")
            {
            }

            KnowledgeBaseException(const std::string& errorMessage) :
                errorMessage_(errorMessage)
            {
            }

            const char* what() const noexcept
            {
                return errorMessage_.c_str();
            }
    };
} // namespace obelisk

#endif