/*
	This file is part of solidity.

	solidity is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	solidity is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
*/
/**
 * Interactive yul optimizer
 */

#include <libdevcore/CommonIO.h>
#include <liblangutil/ErrorReporter.h>
#include <liblangutil/Scanner.h>
#include <libyul/AsmAnalysis.h>
#include <libyul/AsmAnalysisInfo.h>
#include <libsolidity/parsing/Parser.h>
#include <libyul/AsmData.h>
#include <libyul/AsmParser.h>
#include <libyul/AsmPrinter.h>
#include <libsolidity/interface/SourceReferenceFormatter.h>

#include <libyul/optimiser/BlockFlattener.h>
#include <libyul/optimiser/Disambiguator.h>
#include <libyul/optimiser/CommonSubexpressionEliminator.h>
#include <libyul/optimiser/NameCollector.h>
#include <libyul/optimiser/ExpressionSplitter.h>
#include <libyul/optimiser/FunctionGrouper.h>
#include <libyul/optimiser/FunctionHoister.h>
#include <libyul/optimiser/ExpressionInliner.h>
#include <libyul/optimiser/FullInliner.h>
#include <libyul/optimiser/ForLoopInitRewriter.h>
#include <libyul/optimiser/MainFunction.h>
#include <libyul/optimiser/Rematerialiser.h>
#include <libyul/optimiser/ExpressionSimplifier.h>
#include <libyul/optimiser/UnusedPruner.h>
#include <libyul/optimiser/ExpressionJoiner.h>
#include <libyul/optimiser/RedundantAssignEliminator.h>
#include <libyul/optimiser/SSATransform.h>
#include <libyul/optimiser/VarDeclPropagator.h>

#include <libdevcore/JSON.h>

#include <boost/program_options.hpp>

#include <string>
#include <sstream>
#include <iostream>

using namespace std;
using namespace dev;
using namespace langutil;
using namespace dev::solidity;
using namespace dev::solidity::assembly;
using namespace dev::yul;

namespace po = boost::program_options;

class YulOpti
{
public:
	void printErrors(Scanner const& _scanner)
	{
		SourceReferenceFormatter formatter(cout, [&](string const&) -> Scanner const& { return _scanner; });

		for (auto const& error: m_errors)
			formatter.printExceptionInformation(
				*error,
				(error->type() == Error::Type::Warning) ? "Warning" : "Error"
			);
	}

	bool parse(string const& _input)
	{
		ErrorReporter errorReporter(m_errors);
		shared_ptr<Scanner> scanner = make_shared<Scanner>(CharStream(_input), "");
		m_ast = assembly::Parser(errorReporter, assembly::AsmFlavour::Strict).parse(scanner, false);
		if (!m_ast || !errorReporter.errors().empty())
		{
			cout << "Error parsing source." << endl;
			printErrors(*scanner);
			return false;
		}
		m_analysisInfo = make_shared<assembly::AsmAnalysisInfo>();
		AsmAnalyzer analyzer(
			*m_analysisInfo,
			errorReporter,
			EVMVersion::byzantium(),
			boost::none,
			AsmFlavour::Strict
		);
		if (!analyzer.analyze(*m_ast) || !errorReporter.errors().empty())
		{
			cout << "Error analyzing source." << endl;
			printErrors(*scanner);
			return false;
		}
		return true;
	}

	void runInteractive(string source)
	{
		bool disambiguated = false;
		while (true)
		{
			cout << "----------------------" << endl;
			cout << source << endl;
			if (!parse(source))
				return;
			if (!disambiguated)
			{
				*m_ast = boost::get<assembly::Block>(Disambiguator(*m_analysisInfo)(*m_ast));
				m_analysisInfo.reset();
				m_nameDispenser = make_shared<NameDispenser>(*m_ast);
				disambiguated = true;
			}
			cout << "(q)quit/(f)flatten/(c)se/propagate var(d)ecls/(x)plit/(j)oin/(g)rouper/(h)oister/" << endl;
			cout << "  (e)xpr inline/(i)nline/(s)implify/(u)nusedprune/ss(a) transform/" << endl;
			cout << "  (r)edundant assign elim./re(m)aterializer/f(o)r-loop-pre-rewriter? ";
			cout.flush();
			int option = readStandardInputChar();
			cout << ' ' << char(option) << endl;
			switch (option)
			{
			case 'q':
				return;
			case 'f':
				BlockFlattener{}(*m_ast);
				break;
			case 'o':
				ForLoopInitRewriter{}(*m_ast);
				break;
			case 'c':
				(CommonSubexpressionEliminator{})(*m_ast);
				break;
			case 'd':
				(VarDeclPropagator{})(*m_ast);
				break;
			case 'x':
				ExpressionSplitter{*m_nameDispenser}(*m_ast);
				break;
			case 'j':
				ExpressionJoiner::run(*m_ast);
				break;
			case 'g':
				(FunctionGrouper{})(*m_ast);
				break;
			case 'h':
				(FunctionHoister{})(*m_ast);
				break;
			case 'e':
				ExpressionInliner{*m_ast}.run();
				break;
			case 'i':
				FullInliner(*m_ast, *m_nameDispenser).run();
				break;
			case 's':
				ExpressionSimplifier::run(*m_ast);
				break;
			case 'u':
				UnusedPruner::runUntilStabilised(*m_ast);
				break;
			case 'a':
				SSATransform::run(*m_ast, *m_nameDispenser);
				break;
			case 'r':
				RedundantAssignEliminator::run(*m_ast);
				break;
			case 'm':
				Rematerialiser{}(*m_ast);
				break;
			default:
				cout << "Unknown option." << endl;
			}
			source = AsmPrinter{}(*m_ast);
		}
	}

private:
	ErrorList m_errors;
	shared_ptr<assembly::Block> m_ast;
	shared_ptr<AsmAnalysisInfo> m_analysisInfo;
	shared_ptr<NameDispenser> m_nameDispenser;
};

int main(int argc, char** argv)
{
	po::options_description options(
		R"(yulopti, yul optimizer exploration tool.
Usage: yulopti [Options] <file>
Reads <file> as yul code and applies optimizer steps to it,
interactively read from stdin.

Allowed options)",
		po::options_description::m_default_line_length,
		po::options_description::m_default_line_length - 23);
	options.add_options()
		(
			"input-file",
			po::value<string>(),
			"input file"
		)
		("help", "Show this help screen.");

	// All positional options should be interpreted as input files
	po::positional_options_description filesPositions;
	filesPositions.add("input-file", 1);

	po::variables_map arguments;
	try
	{
		po::command_line_parser cmdLineParser(argc, argv);
		cmdLineParser.options(options).positional(filesPositions);
		po::store(cmdLineParser.run(), arguments);
	}
	catch (po::error const& _exception)
	{
		cerr << _exception.what() << endl;
		return 1;
	}

	string input;
	if (arguments.count("input-file"))
		YulOpti{}.runInteractive(readFileAsString(arguments["input-file"].as<string>()));
	else
		cout << options;

	return 0;
}