#include "Compiler.h"

#include <llvm/IR/IRBuilder.h>
#include <llvm/IR/Module.h>

namespace evmcc
{

Compiler::Compiler()
{
	auto& context = llvm::getGlobalContext();
	Types.word8 = llvm::Type::getInt8Ty(context);
	Types.word8ptr = llvm::Type::getInt8PtrTy(context);
	Types.word256 = llvm::Type::getIntNTy(context, 256);
	Types.word256ptr = Types.word256->getPointerTo();
	Types.word256arr = llvm::ArrayType::get(Types.word256, 100);
	Types.size = llvm::Type::getInt64Ty(context);
}


void Compiler::compile(const dev::bytes& bytecode)
{
	using namespace llvm;

	auto& context = getGlobalContext();

	Module* module = new Module("main", context);
	IRBuilder<> builder(context);

	// Create globals for memory, memory size, stack and stack top
	auto memory = new GlobalVariable(*module, Types.word8ptr, false,
		GlobalValue::LinkageTypes::PrivateLinkage,
		Constant::getNullValue(Types.word8ptr), "memory");
	auto memSize = new GlobalVariable(*module, Types.size, false,
		GlobalValue::LinkageTypes::PrivateLinkage,
		ConstantInt::get(Types.size, 0), "memsize");
	auto stack = new GlobalVariable(*module, Types.word256arr, false,
		GlobalValue::LinkageTypes::PrivateLinkage,
		ConstantAggregateZero::get(Types.word256arr), "stack");
	auto stackTop = new GlobalVariable(*module, Types.size, false,
		GlobalValue::LinkageTypes::PrivateLinkage,
		ConstantInt::get(Types.size, 0), "stackTop");

	// Create value for void* malloc(size_t)
	std::vector<Type*> mallocArgTypes = { Types.size };
	Value* mallocVal = Function::Create(FunctionType::get(Types.word8ptr, mallocArgTypes, false),
		GlobalValue::LinkageTypes::ExternalLinkage, "malloc", module);

	// Create main function
	FunctionType* funcType = FunctionType::get(llvm::Type::getInt32Ty(context), false);
	Function* mainFunc = Function::Create(funcType, Function::ExternalLinkage, "main", module);

	BasicBlock* entryBlock = BasicBlock::Create(context, "entry", mainFunc);
	builder.SetInsertPoint(entryBlock);

	// Initialize memory with call to malloc, update memsize
	std::vector<Value*> mallocMemArgs = { ConstantInt::get(Types.size, 100) };
	auto mallocMemCall = builder.CreateCall(mallocVal, mallocMemArgs, "malloc_mem");
	builder.CreateStore(mallocMemCall, memory);
	builder.CreateStore(ConstantInt::get(Types.size, 100), memSize);

	/*
	std::vector<Value*> mallocStackArgs = { ConstantInt::get(sizeTy, 200) };
	auto mallocStackCall = builder.CreateCall(mallocVal, mallocStackArgs, "malloc_stack");
	auto mallocCast = builder.CreatePointerBitCastOrAddrSpaceCast(mallocStackCall, int256ptr);
	builder.CreateStore(mallocCast, stackVal);
	*/

	builder.CreateRet(ConstantInt::get(Type::getInt32Ty(context), 0));

	module->dump();
}

}