//
// Created by anonymus-raccoon on 2/10/20.
//

#include "../CPU.hpp"

namespace ComSquare::CPU
{
	void CPU::RESB()
	{
		this->_registers.p.i = true;
		this->_registers.p.d = false;
		this->_isEmulationMode = true;
		this->_registers.p.m = true;
		this->_registers.p.x_b = true;
		this->_registers.dbr = 0x00;
		this->_registers.pbr = 0x00;
		this->_registers.d = 0x0000;
		this->_registers.sh = 0x01; // the low bit of the stack pointer is undefined on reset.
		this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.reset;
	}

	void CPU::BRK()
	{
		if (this->_isEmulationMode) {
			this->_registers.pc += 2;
			this->_push(this->_registers.pc);
			this->_registers.p.x_b = true;
			this->_push(this->_registers.p.flags);
			this->_registers.p.i = true;
			this->_registers.p.d = false;
			this->_registers.pc = this->_cartridgeHeader.emulationInterrupts.brk;

		} else {
			this->_push(this->_registers.pbr);
			this->_registers.pc += 2;
			this->_push(this->_registers.pc);
			this->_push(this->_registers.p.flags);
			this->_registers.p.i = true;
			this->_registers.p.d = false;
			this->_registers.pbr = 0x0;
			this->_registers.pc = this->_cartridgeHeader.nativeInterrupts.brk;
		}
	}

	void CPU::RTI()
	{
		this->_registers.p.flags = this->_pop();
		this->_registers.pc = this->_pop16();

		if (!this->_isEmulationMode)
			this->_registers.pbr = this->_pop16();
	}
}