#include "../Iinstr.hpp"

class Cbranch : public Iinstr {
	private:
		bool m_taken;
		char m_typ;
	public:
		Cbranch();
		void evalInstr();
		void execInstr();
		std::string toString();
		Iinstr* getNew();
};

/**
 * Name:      create_instruction
 * Purpose:   if compiled as shared library, this functions creates the 
              instruction object

 * Returns:   pointer to instruction object
 */
extern "C" Iinstr* create_instruction() {
    return new Cbranch();
}

Iinstr* Cbranch::getNew()
{
	return new Cbranch();
}
/**
 * Name:      destroy_instruction
 * Purpose:   if compiled as shared library, this functions destoys the 
              instruction object

 * Parameter: IInstruction - the instruction object to delete
 */
extern "C" void destroy_instruction(Iinstr* p) {
    delete p;
}

Cbranch::Cbranch() : m_taken(1), m_typ(0)
{
	opcode = B5(10110);
	name = "branch";
}

void Cbranch::evalInstr()
{
	this->m_s = argbits[0];
	this->m_taken = argbits[1];

	argbits >>= 2;

	dynamic_bitset<> type = argbits;
	type.resize(2);
	this->m_typ = type.to_ulong();

	switch(this->m_typ) {
		case 0:
			this->name = "br";
			break;
		case 1:
			this->name = "call";
			break;
		case 2:
			this->name = "ret";
			this->clockcount = 3;
			break;
		case 3:
			this->name = "reti";
			this->clockcount = 3;
			break;
		default:
			cerr << "What have you done? 2 bits that have more than 4 values?!" << endl;
	}

	argbits >>= 5;

	dynamic_bitset<> immb = argbits;
	immb.resize(16);
	this->m_imm = this->generate16ImmSign(immb.to_ulong());

}

void Cbranch::execInstr()
{
	//cout << "should exec " << this->toString() << endl;
	CDat pc = this->m_cpu->getCurPC();
	switch(this->m_typ) {
		case 1:
			{
			CDat sp = this->m_cpu->getStack();
			sp -= 4;
			this->m_cpu->setRAM(sp, this->m_cpu->getNextPC());
			this->m_cpu->setStack(sp);
			}
		case 0:
			this->m_cpu->setNextPC(pc+this->m_imm);
			break;
		case 2:
		case 3:
			this->m_cpu->setNextPC(this->m_cpu->getRAM(this->m_cpu->getStack()));
			this->m_cpu->setStack(this->m_cpu->getStack()+4);
			break;
		default:
			// nothing
			this->m_cpu->setNextPC(400);
	}
}

std::string Cbranch::toString()
{
	stringstream op;
	op << this->getName();

	if(m_s) op << 'S';

	op << this->getConditionFlag() << (m_taken ? '+' : '-');
	if(m_typ < 2) {
		op << " 0x" << std::hex << m_imm << "(" << std::dec << m_imm << ")";
	}
	return op.str();
}