/***********************************************************************************
 * Copyright (c) 2016, UT-Battelle
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *   * Neither the name of the xacc nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Contributors:
 *   Initial API and implementation - Alex McCaskey
 *
 **********************************************************************************/
#ifndef QUANTUM_GATE_SCAFFOLD_IMPROVEDSCAFFCCAPI_HPP_
#define QUANTUM_GATE_SCAFFOLD_IMPROVEDSCAFFCCAPI_HPP_

#include <cstdlib>
#include "XACCError.hpp"
#include <iostream>
#include <fstream>
#include <boost/algorithm/string.hpp>

#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Support/IRReader.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Type.h"

#include "llvm/Support/Host.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"

#include "clang/AST/ASTConsumer.h"
#include "clang/AST/RecursiveASTVisitor.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/Basic/TargetOptions.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Parse/ParseAST.h"
#include "clang/Lex/Preprocessor.h"

#include "clang/Frontend/DiagnosticOptions.h"
#include "clang/Frontend/TextDiagnosticPrinter.h"

#include "MyASTConsumer.hpp"

using namespace clang;

namespace scaffold {

/**
 * The ScaffCCAPI is a simple utility class that provides
 * methods for interacting with an installed Scaffold compiler.
 * It's main function is to take user-specified XACC kernel
 * source code and compile it to flatted QASM using the
 * Scaffold compiler.
 */
class ImprovedScaffCCAPI {

protected:

	const std::string kernelSource;

	llvm::Module * mod;

public:

	ImprovedScaffCCAPI(const std::string& kernelStr) :
			kernelSource(kernelStr) {
		// Create a temporary scaffold soruce file
		std::ofstream tempSrcFile(".tmpSrcFile.scaffold");
		tempSrcFile << kernelSource;
		tempSrcFile.close();

		// Execute the scaffold compiler
		std::system(
				"/usr/local/scaffold/build/Release+Asserts/bin/clang "
				"-S -c -emit-llvm .tmpSrcFile.scaffold -o out.ll");

		using namespace llvm;

		SMDiagnostic err;
		LLVMContext &ctx = getGlobalContext();
		mod = ParseIRFile("out.ll", err, ctx);
		if (!mod) {
			XACCError("LLVM Module was null");
		}
	}
	/**
	 * Return a string containing flatted QASM representing
	 * the provided high level Scaffold source code. This method
	 * assumes that the Scaffold compiler is on the current user's
	 * PATH and is called scaffcc.
	 *
	 * @param source The scaffold kernel source code.
	 * @return flattenedQASM The QASM representation of the given source.
	 */
	std::string getFlatQASMFromSource(const std::string& source) {

		// Check if scaffcc exists on the PATH
		if (std::system("which scaffcc > /dev/null 2>&1") == 0) {

			// Create a temporary scaffold soruce file
			std::ofstream tempSrcFile(".tmpSrcFile.scaffold");
			tempSrcFile << source;
			tempSrcFile.close();

			// Execute the scaffold compiler
			std::system("scaffcc -fRp .tmpSrcFile.scaffold &> /dev/null");

			// Remove the temporary source file, we don't need it anymore
			std::remove(".tmpSrcFile.scaffold");

			// Read in the generated QASM
			std::ifstream flatQASM(".tmpSrcFile.qasmf");
			std::string qasm((std::istreambuf_iterator<char>(flatQASM)),
					std::istreambuf_iterator<char>());

			// Remove created scaffold files.
			std::remove(".tmpSrcFile.qasmf");
			std::remove(".tmpSrcFile.qasmh");

			// Return the QASM
			return qasm;
		} else {
			XACCError(
					"Cannot find scaffold compiler. Make sure scaffcc is in PATH and executable.");
		}
	}

	std::vector<std::string> getFunctionNames() {

		std::vector<std::string> fNames;
		for (auto i = mod->getFunctionList().begin(), j = mod->getFunctionList().end(); i!=j; ++i) {
			auto fName = i->getName().str();
			if (!(boost::contains(fName, "llvm")
					&& boost::contains(fName, "i16")))
				fNames.push_back(i->getName().str());
		}

		return fNames;
	}

	void checkIfStmts() {

		CompilerInstance CI;
//		DiagnosticOptions diagnosticOptions;
//		TextDiagnosticPrinter *pTextDiagnosticPrinter =
//			new TextDiagnosticPrinter(
//				llvm::outs(), diagnosticOptions, true);
		CI.createDiagnostics(0, 0);//NULL, pTextDiagnosticPrinter);

		TargetOptions targetOptions;
		targetOptions.Triple = llvm::sys::getDefaultTargetTriple();
		TargetInfo *pTargetInfo = TargetInfo::CreateTargetInfo(
				CI.getDiagnostics(), targetOptions);
		CI.setTarget(pTargetInfo);

		CI.createFileManager();
		CI.createSourceManager(CI.getFileManager());
		CI.createPreprocessor();
		CI.getPreprocessorOpts().UsePredefines = false;
		auto astConsumer = new MyASTConsumer();
		CI.setASTConsumer(astConsumer);

		CI.createASTContext();
//		CI.createSema(clang::TU_Complete, NULL);

		const FileEntry *pFile = CI.getFileManager().getFile(".tmpSrcFile.scaffold");
		CI.getSourceManager().createMainFileID(pFile);

		CI.getASTContext().BuiltinInfo.InitializeBuiltins(
			CI.getPreprocessor().getIdentifierTable(), CI.getLangOpts());

//		CI.getDiagnosticClient().BeginSourceFile(
//				CI.getLangOpts(), &(CI.getPreprocessor()));
//		clang::ParseAST(CI.getSema());
//		CI.getDiagnosticClient().EndSourceFile();


		clang::ParseAST(CI.getPreprocessor(), astConsumer, CI.getASTContext());

	}
};

}



#endif