#ifndef CHIP8_CHIP8_H
#define CHIP8_CHIP8_H

#include <string>
#include <stack>
#include "display.h"

class InstructionHandler;

/**
 * The main Chip8 used to emulate/interpret the Chip8 program
 */
class Chip8 {
private:
    /**
     * The memory of the Chip8 program
     */
    unsigned char memory[0xFFF] = {};

    /**
     * The 16 general purpose 8-bit registers, generally used to store memory addresses
     */
    unsigned char v[0x10] = {};

    /**
     * Stack of 16-bit values, used to store addresses the interpreter should return to when finished with a subroutine
     */
    std::stack<unsigned short> stack{};

    /**
     * The program counter which holds the currently executing address
     */
    unsigned short pc;

    /**
     * The Display object holding information and functions used for the display
     */
    Display display;

    /**
     * The instruction handler used to handle instructions
     */
    InstructionHandler* instructionHandler;
public:
    Chip8();
    ~Chip8();

    /**
     * Loads a rom in the memory
     * @param rom The rom to be loaded in the memory
     */
    void loadRom(const std::string& rom);

    /**
     * Gets the Display object
     * @return
     */
    [[nodiscard]] Display getDisplay() const;

    /**
     * Cycle to handle the next instruction
     */
    void emulateCycle();

    /**
     * Pops a 16-bit value from the stack
     * @return a unsigned 16-bit integer
     */
    [[nodiscard]] unsigned short popFromStack();

    void pushToStack(unsigned short value);

    /**
     * Sets the program counter (PC) to the given value
     */
    void setProgramCounter(unsigned short value);

    /**
     * Gets the program counter (PC)
     * @return
     */
    [[nodiscard]] unsigned short getProgramCounter() const;

    /**
     * Gets a value from the register (V)
     * @param i The index
     * @return
     */
    unsigned char getRegister(unsigned char i);

    /**
     * Sets a value in the register (V)
     *
     * @param i The index of the register to set
     * @param value The value to be set
     */
    void setRegister(unsigned char i, unsigned char value);
};
#endif //CHIP8_CHIP8_H