#include "internal.hpp"
#include "SharedMemoryAccess.hpp"
#include "vkvm.hpp"

#include <csignal>

namespace vkvm {

    Impl impl;

    auto sendSignal(pid_t pid, int signalNumber) -> void {
        kill(pid, signalNumber);
    }

    auto onSignal(int signalNumber, void(*callback)(int)) -> void {
        signal(signalNumber, callback);
    }

    auto getInterruptTable() -> InterruptEntry * {
        return reinterpret_cast<InterruptEntry *>(getSharedMemory() + sizeof(Registers) + impl.reservedSize);
    }

    auto getRegisters() -> Registers * {
        return reinterpret_cast<Registers *>(getSharedMemory());
    }

    auto getTextArea() -> char * {
        return ((getSharedMemory() + sizeof(Registers) + impl.reservedSize) +
                sizeof(InterruptEntry) * impl.interruptEntyCount);
    }

    auto getPixelArea() -> char * {
        return (((getSharedMemory() + sizeof(Registers) + impl.reservedSize) +
                 sizeof(InterruptEntry) * impl.interruptEntyCount) +
                getCharactersPerRow() * getCharactersPerColumn());
    }

    auto callEvent(EventType type) -> bool {
        auto ivt = getInterruptTable();
        for(int i = 0; i < impl.interruptEntrysPerEventType;i++){
            auto &entry= ivt[type * impl.interruptEntrysPerEventType + i];
            if (entry.pid != 0) {
                sendSignal(entry.pid, entry.signum);
            }
        }
        return true;
    }

    auto setLayoutVersion(LayoutVersion newValue) -> void {
        lockSharedMemory();
        getRegisters()->layout_version = newValue;
        unlockSharedMemory();
        callEvent(EventType::UpdateControlRegisters);
    }

    auto setCharactersPerColumn(int newValue) -> void {
        lockSharedMemory();
        getRegisters()->characters_per_column = newValue;
        unlockSharedMemory();
        callEvent(EventType::UpdateControlRegisters);
    }

    auto setCharactersPerRow(int newValue) -> void {
        lockSharedMemory();
        getRegisters()->characters_per_row = newValue;
        unlockSharedMemory();
        callEvent(EventType::UpdateControlRegisters);
    }

    auto setMousePosition(int x, int y) -> void {
        lockSharedMemory();
        getRegisters()->mouse_pos_x = x;
        getRegisters()->mouse_pos_y = y;
        unlockSharedMemory();
        callEvent(EventType::UpdateControlRegisters);
    }

    auto buttonPressed(KeyCode keyCode) -> void {
        lockSharedMemory();
        auto reg = getRegisters();
        reg->keyboardBuffer[reg->keyboardBuffer_index_write++] = keyCode;
        if (reg->keyboardBuffer_index_write >= keyboardBufferSize) {
            reg->keyboardBuffer_index_write = 0;
        }
        unlockSharedMemory();
    }

    auto getRegisteredProcesses(EventType eventType) -> std::vector<int> {
        std::vector<int> result;
        auto ivt = getInterruptTable();
        for(int i = 0; i < impl.interruptEntrysPerEventType;i++){
            auto &entry= ivt[eventType * impl.interruptEntrysPerEventType + i];
            if (entry.pid != 0) {
                result.push_back(entry.pid);
            }
        }
        return result;
    }

}