#include <utility>
#include "LLVMVisitor.h"

LLVMVisitor::LLVMVisitor(const char* fileName) : outFile(std::ofstream(fileName)), reg() {
	if (!outFile.is_open())
		throw std::runtime_error("Couldn't open file for writing!");
	outFile << "define i32 @main() {\n";
}

void LLVMVisitor::finalizeFile() {
	outFile << "ret i32 0\n}\n";
}

std::string LLVMVisitor::Visit(const Integer& vint) {
	return std::to_string(vint.get_value());
}

std::string LLVMVisitor::Visit(const Float& vfloat) {
	return std::to_string(vfloat.get_value());
}

void f_add(std::string reg, std::string first, std::string second, std::ofstream& of) {
	of << reg << " = add i32 " << first << ", " << second << "\n";
}

void f_sub(std::string reg, std::string first, std::string second, std::ofstream& of) {
	of << reg << " = sub i32 " << first << ", " << second << "\n";
}

std::string LLVMVisitor::rightAssoc(BiFout f, const BuiltInFunction& bfun, unsigned i) {
	std::string leftArg = bfun.get_args()[i]->Visit(*this);
	std::string rightArg;
	if (bfun.get_args().size() - 2 == i)
		rightArg = bfun.get_args()[i+1]->Visit(*this);
	else
		rightArg = rightAssoc(f, bfun, i+1);

	std::string valRegister = *(reg++);
	f(valRegister, leftArg, rightArg, outFile);
	return valRegister;
}

std::string LLVMVisitor::Visit(const BuiltInFunction& bfun) {
	if (bfun.get_name() == "+") return rightAssoc(f_add, bfun);
	if (bfun.get_name() == "-") return rightAssoc(f_sub, bfun);

	return "";
}