#ifndef LIBRARY_INTERNAL_HPP
#define LIBRARY_INTERNAL_HPP

#include "EventType.hpp"
#include "KeyCode.hpp"
#include "LayoutVersion.hpp"
#include "GraphicMode.hpp"
#include "Color.hpp"
#include <sys/types.h>
#include <vector>
#include <functional>

namespace vkvm {

/**
 * the Control Registers
 * @author Julian Hinxlage
 * @since 0.1.0
 */
    struct Registers {
        int layout_version;
        int trigger_reset;
        int width_pixels;
        int height_pixels;
        GraphicMode graphicMode;
        int autoRedrawInterval;
        int timerInterruptInterval;
        Color background_color;
        Color foreground_color;
        int characters_per_row;
        int characters_per_column;
        int textMode_font;
        int textMode_font_width;
        int textMode_font_height;
        int mouse_pos_x;
        int mouse_pos_y;
        short keyboardBuffer[16];
        int keyboardBuffer_index_write;
        int keyboardBuffer_index_read;
    };

    struct InterruptEntry {
        int pid;
        int signum;
    };

/**
 * internal values for the library.
 */
    struct Impl {
        int sharedMemoryPid;
        key_t sharedMemoryKey;
        int sharedMemorySize;
        int interruptEntyCount = 64;
        int reservedSize = 1024;
        std::vector<std::function<void()>> eventTable;
    };

    extern Impl impl;

/**
 * send a signal to a process
 * @param pid of the process to which the signal is send
 * @param signalNumber
 */
    auto sendSignal(pid_t pid, int signalNumber) -> void;

/**
 * calls the callback if a signal is received
 * @param signalNumber
 */
    auto onSignal(int signalNumber, void(*callback)(int)) -> void;


    auto getInterrupTable() -> InterruptEntry *;

    auto getRegisters() -> Registers *;

    auto getTextArea() -> char * ;

    auto getPixelArea() -> char *;


/**
 * set layout version.
 * @param newValue new layout version number.
 */
    auto setLayoutVersion(LayoutVersion newValue) -> void;

/**
 * set characters per column for current font.
 * @param newValue characters per column.
 */
    auto setCharactersPerColumn(int newValue) -> void;

/**
 * set characters per row for current font.
 * @param newValue
 */
    auto setCharactersPerRow(int newValue) -> void;

/**
 * call a specific event.
 * @param type
 * @return true if there is a handler registered.
 */
    auto callEvent(EventType type) -> bool;

/**
 * set mouse position to x,y value.
 * @param x x coordinate
 * @param y y coordinate
 */
    auto setMousePosition(int x, int y) -> void;

/**
 * register pressed button.
 * @param keyCode pressed key.
 */
    auto buttonPressed(KeyCode keyCode) -> void;

// Shared Memory Layout
// --------------------------------------------------------------------
// struct ControlRegisters
// char reserved[1024]
// Interrupt Vector Table [64]
// text area [max_textMode_width * max_textMode_height]
// pixel area [max_height_pixels * max_height_pixels * sizeof(uint_32)]

}

#endif