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

LLVMVisitor::LLVMVisitor(const char* fileName) : outFile(std::ofstream(fileName)), greg("@v"), lreg("%v") {
	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());
}

std::string LLVMVisitor::Visit(const Name& vname) {
	return vname.get_value();
}

std::string LLVMVisitor::Visit(const Funcall& vfuncall) {
	if (std::find(gfuncs.begin(), gfuncs.end(), vfuncall) == gfuncs.end())
		throw std::runtime_error("Function doesn't exist!");

	std::vector<std::string> pargs;
	for (Value* arg : vfuncall.get_args())
		pargs.push_back(arg->Visit(*this));

	std::string valReg = *(lreg++);
	outFile << valReg << " = call i32 " << vfuncall.get_funname() << "(";
	for (std::string arg : pargs)
		outFile << "i32 " << arg << ", ";
	outFile << ")\n";
	return valReg;
}

void f_add(std::string reg, Value::T_Primitive ty, std::string first, std::string second, std::ofstream& of) {
	of << reg << " = ";
	switch(ty) {
		case Value::T_integer: of << "add i32"; break;
		case Value::T_float: of << "fadd double"; break;
		default: throw std::runtime_error("Invalid type for function!");
	}
	of << " " << first << ", " << second << "\n";
}

void f_sub(std::string reg, Value::T_Primitive ret, std::string first, std::string second, std::ofstream& of) {
	of << reg << " = ";
	switch(ret) {
		case Value::T_integer: of << "sub i32"; break;
		case Value::T_float: of << "fsub double"; break;
		default: throw std::runtime_error("Invalid type for function!");
	}
	of << " " << 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 = *(lreg++);
	f(valRegister, bfun.RetType(), 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 "";
}