/*
	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/>.
*/
// SPDX-License-Identifier: GPL-3.0

#include <test/libsolidity/GasTest.h>
#include <test/Common.h>
#include <libsolutil/CommonIO.h>
#include <libsolutil/JSON.h>
#include <liblangutil/SourceReferenceFormatter.h>
#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/predicate.hpp>
#include <boost/filesystem.hpp>
#include <boost/test/unit_test.hpp>
#include <boost/throw_exception.hpp>
#include <fstream>
#include <stdexcept>

using namespace solidity::langutil;
using namespace solidity::frontend;
using namespace solidity::frontend::test;
using namespace solidity;
using namespace std;
using namespace boost::unit_test;

GasTest::GasTest(string const& _filename):
	TestCase(_filename)
{
	m_source = m_reader.source();
	m_optimise = m_reader.boolSetting("optimize", false);
	m_optimiseYul = m_reader.boolSetting("optimize-yul", false);
	m_optimiseRuns = m_reader.sizetSetting("optimize-runs", OptimiserSettings{}.expectedExecutionsPerDeployment);
	parseExpectations(m_reader.stream());
}

void GasTest::parseExpectations(std::istream& _stream)
{
	map<std::string, std::string>* currentKind = nullptr;
	string line;

	while (getline(_stream, line))
		if (!boost::starts_with(line, "// "))
			BOOST_THROW_EXCEPTION(runtime_error("Invalid expectation: expected \"// \"."));
		else if (boost::ends_with(line, ":"))
		{
			string kind = line.substr(3, line.length() - 4);
			boost::trim(kind);
			currentKind = &m_expectations[move(kind)];
		}
		else if (!currentKind)
			BOOST_THROW_EXCEPTION(runtime_error("No function kind specified. Expected \"creation:\", \"external:\" or \"internal:\"."));
		else
		{
			auto it = line.begin() + 3;
			skipWhitespace(it, line.end());
			auto functionNameBegin = it;
			while (it != line.end() && *it != ':')
				++it;
			string functionName(functionNameBegin, it);
			if (functionName == "fallback")
				functionName.clear();
			expect(it, line.end(), ':');
			skipWhitespace(it, line.end());
			if (it == line.end())
				BOOST_THROW_EXCEPTION(runtime_error("Invalid expectation: expected gas cost."));
			(*currentKind)[functionName] = std::string(it, line.end());
		}
}

void GasTest::printUpdatedExpectations(ostream& _stream, string const& _linePrefix) const
{
	Json::Value estimates = compiler().gasEstimates(compiler().lastContractName());
	for (auto groupIt = estimates.begin(); groupIt != estimates.end(); ++groupIt)
	{
		_stream << _linePrefix << groupIt.key().asString() << ":" << std::endl;
		for (auto it = groupIt->begin(); it != groupIt->end(); ++it)
		{
			_stream << _linePrefix << "  ";
			if (it.key().asString().empty())
				_stream << "fallback";
			else
				_stream << it.key().asString();
			_stream << ": " << it->asString() << std::endl;
		}
	}
}

TestCase::TestResult GasTest::run(ostream& _stream, string const& _linePrefix, bool _formatted)
{
	string const preamble = "pragma solidity >=0.0;\n// SPDX-License-Identifier: GPL-3.0\n";
	compiler().reset();
	// Prerelease CBOR metadata varies in size due to changing version numbers and build dates.
	// This leads to volatile creation cost estimates. Therefore we force the compiler to
	// release mode for testing gas estimates.
	compiler().setMetadataFormat(CompilerStack::MetadataFormat::NoMetadata);
	OptimiserSettings settings = m_optimise ? OptimiserSettings::standard() : OptimiserSettings::minimal();
	if (m_optimiseYul)
	{
		settings.runYulOptimiser = m_optimise;
		settings.optimizeStackAllocation = m_optimise;
	}
	settings.expectedExecutionsPerDeployment = m_optimiseRuns;
	compiler().setOptimiserSettings(settings);
	compiler().setSources({{"", preamble + m_source}});

	if (!compiler().parseAndAnalyze() || !compiler().compile())
	{
		SourceReferenceFormatter{_stream, compiler(), _formatted, false}
			.printErrorInformation(compiler().errors());
		return TestResult::FatalError;
	}

	Json::Value estimateGroups = compiler().gasEstimates(compiler().lastContractName());
	if (
		m_expectations.size() == estimateGroups.size() &&
		boost::all(m_expectations, [&](auto const& expectations) {
		auto const& estimates = estimateGroups[expectations.first];
		return estimates.size() == expectations.second.size() &&
			boost::all(expectations.second, [&](auto const& entry) {
				return entry.second == estimates[entry.first].asString();
			});
		})
	)
		return TestResult::Success;
	else
	{
		_stream << _linePrefix << "Expected:" << std::endl;
		for (auto const& expectations: m_expectations)
		{
			_stream << _linePrefix << "  " << expectations.first << ":" << std::endl;
			for (auto const& entry: expectations.second)
				_stream << _linePrefix
					<< "    "
					<< (entry.first.empty() ? "fallback" : entry.first)
					<< ": "
					<< entry.second
					<< std::endl;
		}
		_stream << _linePrefix << "Obtained:" << std::endl;
		printUpdatedExpectations(_stream, _linePrefix + "  ");
		return TestResult::Failure;
	}
}

void GasTest::printSource(ostream& _stream, string const& _linePrefix, bool) const
{
	string line;
	istringstream input(m_source);
	while (getline(input, line))
		_stream << _linePrefix << line << std::endl;
}
