/*
	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/>.
*/

#include <test/libyul/YulOptimizerTest.h>

#include <test/libsolidity/util/SoltestErrors.h>
#include <test/libyul/Common.h>
#include <test/Common.h>

#include <libyul/optimiser/BlockFlattener.h>
#include <libyul/optimiser/VarDeclInitializer.h>
#include <libyul/optimiser/VarNameCleaner.h>
#include <libyul/optimiser/ControlFlowSimplifier.h>
#include <libyul/optimiser/DeadCodeEliminator.h>
#include <libyul/optimiser/Disambiguator.h>
#include <libyul/optimiser/CallGraphGenerator.h>
#include <libyul/optimiser/CircularReferencesPruner.h>
#include <libyul/optimiser/ConditionalUnsimplifier.h>
#include <libyul/optimiser/ConditionalSimplifier.h>
#include <libyul/optimiser/CommonSubexpressionEliminator.h>
#include <libyul/optimiser/NameCollector.h>
#include <libyul/optimiser/EquivalentFunctionCombiner.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/ForLoopConditionIntoBody.h>
#include <libyul/optimiser/ForLoopConditionOutOfBody.h>
#include <libyul/optimiser/ForLoopInitRewriter.h>
#include <libyul/optimiser/LoadResolver.h>
#include <libyul/optimiser/LoopInvariantCodeMotion.h>
#include <libyul/optimiser/MainFunction.h>
#include <libyul/optimiser/NameDisplacer.h>
#include <libyul/optimiser/Rematerialiser.h>
#include <libyul/optimiser/ExpressionSimplifier.h>
#include <libyul/optimiser/UnusedPruner.h>
#include <libyul/optimiser/ExpressionJoiner.h>
#include <libyul/optimiser/OptimiserStep.h>
#include <libyul/optimiser/SSAReverser.h>
#include <libyul/optimiser/SSATransform.h>
#include <libyul/optimiser/Semantics.h>
#include <libyul/optimiser/RedundantAssignEliminator.h>
#include <libyul/optimiser/StructuralSimplifier.h>
#include <libyul/optimiser/StackCompressor.h>
#include <libyul/optimiser/Suite.h>
#include <libyul/backends/evm/ConstantOptimiser.h>
#include <libyul/backends/evm/EVMDialect.h>
#include <libyul/backends/evm/EVMMetrics.h>
#include <libyul/backends/wasm/WordSizeTransform.h>
#include <libyul/backends/wasm/WasmDialect.h>
#include <libyul/AsmPrinter.h>
#include <libyul/AsmParser.h>
#include <libyul/AsmAnalysis.h>
#include <libyul/AssemblyStack.h>
#include <liblangutil/SourceReferenceFormatter.h>

#include <liblangutil/ErrorReporter.h>
#include <liblangutil/Scanner.h>

#include <libsolutil/AnsiColorized.h>

#include <boost/test/unit_test.hpp>
#include <boost/algorithm/string.hpp>

#include <fstream>
#include <variant>

using namespace solidity;
using namespace solidity::util;
using namespace solidity::langutil;
using namespace solidity::yul;
using namespace solidity::yul::test;
using namespace solidity::frontend;
using namespace solidity::frontend::test;
using namespace std;

YulOptimizerTest::YulOptimizerTest(string const& _filename):
	EVMVersionRestrictedTestCase(_filename)
{
	boost::filesystem::path path(_filename);

	if (path.empty() || std::next(path.begin()) == path.end() || std::next(std::next(path.begin())) == path.end())
		BOOST_THROW_EXCEPTION(runtime_error("Filename path has to contain a directory: \"" + _filename + "\"."));
	m_optimizerStep = std::prev(std::prev(path.end()))->string();

	m_source = m_reader.source();

	auto dialectName = m_reader.stringSetting("dialect", "evm");
	m_dialect = &dialect(dialectName, solidity::test::CommonOptions::get().evmVersion());

	m_expectation = m_reader.simpleExpectations();
}

TestCase::TestResult YulOptimizerTest::run(ostream& _stream, string const& _linePrefix, bool const _formatted)
{
	if (!parse(_stream, _linePrefix, _formatted))
		return TestResult::FatalError;

	soltestAssert(m_dialect, "Dialect not set.");

	updateContext();

	if (m_optimizerStep == "disambiguator")
		disambiguate();
	else if (m_optimizerStep == "nameDisplacer")
	{
		disambiguate();
		NameDisplacer{
			*m_nameDispenser,
			{"illegal1"_yulstring, "illegal2"_yulstring, "illegal3"_yulstring, "illegal4"_yulstring, "illegal5"_yulstring}
		}(*m_ast);
	}
	else if (m_optimizerStep == "blockFlattener")
	{
		disambiguate();
		BlockFlattener::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "constantOptimiser")
	{
		GasMeter meter(dynamic_cast<EVMDialect const&>(*m_dialect), false, 200);
		ConstantOptimiser{dynamic_cast<EVMDialect const&>(*m_dialect), meter}(*m_ast);
	}
	else if (m_optimizerStep == "varDeclInitializer")
		VarDeclInitializer::run(*m_context, *m_ast);
	else if (m_optimizerStep == "varNameCleaner")
		VarNameCleaner::run(*m_context, *m_ast);
	else if (m_optimizerStep == "forLoopConditionIntoBody")
	{
		disambiguate();
		ForLoopConditionIntoBody::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "forLoopInitRewriter")
	{
		disambiguate();
		ForLoopInitRewriter::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "commonSubexpressionEliminator")
	{
		disambiguate();
		CommonSubexpressionEliminator::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "conditionalUnsimplifier")
	{
		disambiguate();
		ConditionalUnsimplifier::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "conditionalSimplifier")
	{
		disambiguate();
		ConditionalSimplifier::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "expressionSplitter")
		ExpressionSplitter::run(*m_context, *m_ast);
	else if (m_optimizerStep == "expressionJoiner")
	{
		disambiguate();
		ExpressionJoiner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "splitJoin")
	{
		disambiguate();
		ExpressionSplitter::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "functionGrouper")
	{
		disambiguate();
		FunctionGrouper::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "functionHoister")
	{
		disambiguate();
		FunctionHoister::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "expressionInliner")
	{
		disambiguate();
		ExpressionInliner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "fullInliner")
	{
		disambiguate();
		FunctionHoister::run(*m_context, *m_ast);
		FunctionGrouper::run(*m_context, *m_ast);
		ExpressionSplitter::run(*m_context, *m_ast);
		FullInliner::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "mainFunction")
	{
		disambiguate();
		FunctionGrouper::run(*m_context, *m_ast);
		MainFunction::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "rematerialiser")
	{
		disambiguate();
		Rematerialiser::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "expressionSimplifier")
	{
		disambiguate();
		ExpressionSimplifier::run(*m_context, *m_ast);
		ExpressionSimplifier::run(*m_context, *m_ast);
		ExpressionSimplifier::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "fullSimplify")
	{
		disambiguate();
		ExpressionSplitter::run(*m_context, *m_ast);
		ForLoopInitRewriter::run(*m_context, *m_ast);
		CommonSubexpressionEliminator::run(*m_context, *m_ast);
		ExpressionSimplifier::run(*m_context, *m_ast);
		UnusedPruner::run(*m_context, *m_ast);
		CircularReferencesPruner::run(*m_context, *m_ast);
		DeadCodeEliminator::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "unusedPruner")
	{
		disambiguate();
		UnusedPruner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "circularReferencesPruner")
	{
		disambiguate();
		FunctionHoister::run(*m_context, *m_ast);
		CircularReferencesPruner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "deadCodeEliminator")
	{
		disambiguate();
		ForLoopInitRewriter::run(*m_context, *m_ast);
		DeadCodeEliminator::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "ssaTransform")
	{
		disambiguate();
		SSATransform::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "redundantAssignEliminator")
	{
		disambiguate();
		RedundantAssignEliminator::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "ssaPlusCleanup")
	{
		disambiguate();
		SSATransform::run(*m_context, *m_ast);
		RedundantAssignEliminator::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "loadResolver")
	{
		disambiguate();
		ForLoopInitRewriter::run(*m_context, *m_ast);
		ExpressionSplitter::run(*m_context, *m_ast);
		CommonSubexpressionEliminator::run(*m_context, *m_ast);
		ExpressionSimplifier::run(*m_context, *m_ast);

		LoadResolver::run(*m_context, *m_ast);

		UnusedPruner::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
		ExpressionJoiner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "loopInvariantCodeMotion")
	{
		disambiguate();
		ForLoopInitRewriter::run(*m_context, *m_ast);
		LoopInvariantCodeMotion::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "controlFlowSimplifier")
	{
		disambiguate();
		ControlFlowSimplifier::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "structuralSimplifier")
	{
		disambiguate();
		ForLoopInitRewriter::run(*m_context, *m_ast);
		LiteralRematerialiser::run(*m_context, *m_ast);
		StructuralSimplifier::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "equivalentFunctionCombiner")
	{
		disambiguate();
		EquivalentFunctionCombiner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "ssaReverser")
	{
		disambiguate();
		SSAReverser::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "ssaAndBack")
	{
		disambiguate();
		// apply SSA
		SSATransform::run(*m_context, *m_ast);
		RedundantAssignEliminator::run(*m_context, *m_ast);
		// reverse SSA
		SSAReverser::run(*m_context, *m_ast);
		CommonSubexpressionEliminator::run(*m_context, *m_ast);
		UnusedPruner::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "stackCompressor")
	{
		disambiguate();
		FunctionGrouper::run(*m_context, *m_ast);
		size_t maxIterations = 16;
		Object obj;
		obj.code = m_ast;
		StackCompressor::run(*m_dialect, obj, true, maxIterations);
		m_ast = obj.code;
		BlockFlattener::run(*m_context, *m_ast);
	}
	else if (m_optimizerStep == "wordSizeTransform")
	{
		disambiguate();
		ExpressionSplitter::run(*m_context, *m_ast);
		WordSizeTransform::run(*m_dialect, *m_dialect, *m_ast, *m_nameDispenser);
	}
	else if (m_optimizerStep == "fullSuite")
	{
		GasMeter meter(dynamic_cast<EVMDialect const&>(*m_dialect), false, 200);
		yul::Object obj;
		obj.code = m_ast;
		obj.analysisInfo = m_analysisInfo;
		OptimiserSuite::run(*m_dialect, &meter, obj, true);
	}
	else
	{
		AnsiColorized(_stream, _formatted, {formatting::BOLD, formatting::RED}) << _linePrefix << "Invalid optimizer step: " << m_optimizerStep << endl;
		return TestResult::FatalError;
	}

	m_obtainedResult = "step: " + m_optimizerStep + "\n\n" + AsmPrinter{ *m_dialect }(*m_ast) + "\n";

	if (m_expectation != m_obtainedResult)
	{
		string nextIndentLevel = _linePrefix + "  ";
		AnsiColorized(_stream, _formatted, {formatting::BOLD, formatting::CYAN}) << _linePrefix << "Expected result:" << endl;
		// TODO could compute a simple diff with highlighted lines
		printIndented(_stream, m_expectation, nextIndentLevel);
		AnsiColorized(_stream, _formatted, {formatting::BOLD, formatting::CYAN}) << _linePrefix << "Obtained result:" << endl;
		printIndented(_stream, m_obtainedResult, nextIndentLevel);
		return TestResult::Failure;
	}
	return TestResult::Success;
}

void YulOptimizerTest::printSource(ostream& _stream, string const& _linePrefix, bool const) const
{
	printIndented(_stream, m_source, _linePrefix);
}

void YulOptimizerTest::printUpdatedExpectations(ostream& _stream, string const& _linePrefix) const
{
	printIndented(_stream, m_obtainedResult, _linePrefix);
}

void YulOptimizerTest::printIndented(ostream& _stream, string const& _output, string const& _linePrefix) const
{
	stringstream output(_output);
	string line;
	while (getline(output, line))
		_stream << _linePrefix << line << endl;
}

bool YulOptimizerTest::parse(ostream& _stream, string const& _linePrefix, bool const _formatted)
{
	ErrorList errors;
	soltestAssert(m_dialect, "");
	std::tie(m_ast, m_analysisInfo) = yul::test::parse(m_source, *m_dialect, errors);
	if (!m_ast || !m_analysisInfo || !errors.empty())
	{
		AnsiColorized(_stream, _formatted, {formatting::BOLD, formatting::RED}) << _linePrefix << "Error parsing source." << endl;
		printErrors(_stream, errors);
		return false;
	}
	return true;
}

void YulOptimizerTest::disambiguate()
{
	*m_ast = std::get<Block>(Disambiguator(*m_dialect, *m_analysisInfo)(*m_ast));
	m_analysisInfo.reset();
	updateContext();
}

void YulOptimizerTest::updateContext()
{
	m_nameDispenser = make_unique<NameDispenser>(*m_dialect, *m_ast, m_reservedIdentifiers);
	m_context = make_unique<OptimiserStepContext>(OptimiserStepContext{
		*m_dialect,
		*m_nameDispenser,
		m_reservedIdentifiers
	});
}

void YulOptimizerTest::printErrors(ostream& _stream, ErrorList const& _errors)
{
	SourceReferenceFormatter formatter(_stream);

	for (auto const& error: _errors)
		formatter.printErrorInformation(*error);
}