/*
	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/libsolidity/util/TestFileParser.h>

#include <test/Options.h>
#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/predicate.hpp>
#include <boost/optional.hpp>
#include <boost/throw_exception.hpp>
#include <fstream>
#include <memory>
#include <stdexcept>

using namespace dev;
using namespace langutil;
using namespace solidity;
using namespace dev::solidity::test;
using namespace std;
using namespace soltest;

namespace
{
	bool isIdentifierStart(char c)
	{
		return c == '_' || c == '$' || ('a' <= c && c <= 'z') || ('A' <= c && c <= 'Z');
	}
	bool isIdentifierPart(char c)
	{
		return isIdentifierStart(c) || isdigit(c);
	}
}

vector<dev::solidity::test::FunctionCall> TestFileParser::parseFunctionCalls()
{
	vector<FunctionCall> calls;
	if (!accept(Token::EOS))
	{
		assert(m_scanner.currentToken() == Token::Unknown);
		m_scanner.scanNextToken();

		while (!accept(Token::EOS))
		{
			if (!accept(Token::Whitespace))
			{
				FunctionCall call;

				/// If this is not the first call in the test,
				/// the last call to parseParameter could have eaten the
				/// new line already. This could only be fixed with a one
				/// token lookahead that checks parseParameter
				/// if the next token is an identifier.
				if (calls.empty())
					expect(Token::Newline);
				else
					accept(Token::Newline, true);

				call.signature = parseFunctionSignature();
				if (accept(Token::Comma, true))
					call.value = parseFunctionCallValue();
				if (accept(Token::Colon, true))
					call.arguments = parseFunctionCallArguments();

				if (accept(Token::Newline, true))
					call.displayMode = FunctionCall::DisplayMode::MultiLine;

				call.arguments.comment = parseComment();

				if (accept(Token::Newline, true))
					call.displayMode = FunctionCall::DisplayMode::MultiLine;

				expect(Token::Arrow);
				call.expectations = parseFunctionCallExpectations();
				call.expectations.comment = parseComment();

				calls.emplace_back(std::move(call));
			}
		}
	}
	return calls;
}

bool TestFileParser::accept(soltest::Token _token, bool const _expect)
{
	if (m_scanner.currentToken() != _token)
		return false;
	if (_expect)
		return expect(_token);
	return true;
}

bool TestFileParser::expect(soltest::Token _token, bool const _advance)
{
	if (m_scanner.currentToken() != _token || m_scanner.currentToken() == Token::Invalid)
		throw Error(
			Error::Type::ParserError,
			"Unexpected " + formatToken(m_scanner.currentToken()) + ": \"" +
			m_scanner.currentLiteral() + "\". " +
			"Expected \"" + formatToken(_token) + "\"."
			);
	if (_advance)
		m_scanner.scanNextToken();
	return true;
}

string TestFileParser::parseFunctionSignature()
{
	string signature = m_scanner.currentLiteral();
	expect(Token::Identifier);

	signature += formatToken(Token::LParen);
	expect(Token::LParen);

	string parameters;
	if (!accept(Token::RParen, false))
		parameters = parseIdentifierOrTuple();

	while (accept(Token::Comma))
	{
		parameters += formatToken(Token::Comma);
		expect(Token::Comma);
		parameters += parseIdentifierOrTuple();
	}
	if (accept(Token::Arrow, true))
		throw Error(Error::Type::ParserError, "Invalid signature detected: " + signature);

	signature += parameters;

	expect(Token::RParen);
	signature += formatToken(Token::RParen);
	return signature;
}

u256 TestFileParser::parseFunctionCallValue()
{
	u256 value = convertNumber(parseNumber());
	expect(Token::Ether);
	return value;
}

FunctionCallArgs TestFileParser::parseFunctionCallArguments()
{
	FunctionCallArgs arguments;

	auto param = parseParameter();
	if (param.abiType.type == ABIType::None)
		throw Error(Error::Type::ParserError, "No argument provided.");
	arguments.parameters.emplace_back(param);

	while (accept(Token::Comma, true))
		arguments.parameters.emplace_back(parseParameter());
	return arguments;
}

FunctionCallExpectations TestFileParser::parseFunctionCallExpectations()
{
	FunctionCallExpectations expectations;

	auto param = parseParameter();
	if (param.abiType.type == ABIType::None)
	{
		expectations.failure = false;
		return expectations;
	}
	expectations.result.emplace_back(param);

	while (accept(Token::Comma, true))
		expectations.result.emplace_back(parseParameter());

	/// We have always one virtual parameter in the parameter list.
	/// If its type is FAILURE, the expected result is also a REVERT etc.
	if (expectations.result.at(0).abiType.type != ABIType::Failure)
		expectations.failure = false;
	return expectations;
}

Parameter TestFileParser::parseParameter()
{
	Parameter parameter;
	if (accept(Token::Newline, true))
		parameter.format.newline = true;
	auto literal = parseABITypeLiteral();
	parameter.rawBytes = literal.first;
	parameter.abiType = literal.second;
	return parameter;
}

pair<bytes, ABIType> TestFileParser::parseABITypeLiteral()
{
	try
	{
		u256 number{0};
		ABIType abiType{ABIType::None, 0};

		if (accept(Token::Sub))
		{
			abiType = ABIType{ABIType::SignedDec, 32};
			expect(Token::Sub);
			number = convertNumber(parseNumber()) * -1;
		}
		else
		{
			if (accept(Token::Number))
			{
				abiType = ABIType{ABIType::UnsignedDec, 32};
				number = convertNumber(parseNumber());
			}
			else if (accept(Token::Failure, true))
			{
				abiType = ABIType{ABIType::Failure, 0};
				return make_pair(bytes{}, abiType);
			}
		}
		return make_pair(toBigEndian(number), abiType);
	}
	catch (std::exception const&)
	{
		throw Error(Error::Type::ParserError, "Number encoding invalid.");
	}
}

string TestFileParser::parseIdentifierOrTuple()
{
	string identOrTuple;

	if (accept(Token::Identifier))
	{
		identOrTuple = m_scanner.currentLiteral();
		expect(Token::Identifier);
		return identOrTuple;
	}
	expect(Token::LParen);
	identOrTuple += formatToken(Token::LParen);
	identOrTuple += parseIdentifierOrTuple();

	while (accept(Token::Comma))
	{
		identOrTuple += formatToken(Token::Comma);
		expect(Token::Comma);
		identOrTuple += parseIdentifierOrTuple();
	}
	expect(Token::RParen);
	identOrTuple += formatToken(Token::RParen);
	return identOrTuple;
}

string TestFileParser::parseComment()
{
	string comment = m_scanner.currentLiteral();
	if (accept(Token::Comment, true))
		return comment;
	return string{};
}

string TestFileParser::parseNumber()
{
	string literal = m_scanner.currentLiteral();
	expect(Token::Number);
	return literal;
}

u256 TestFileParser::convertNumber(string const& _literal)
{
	try {
		return u256{_literal};
	}
	catch (std::exception const&)
	{
		throw Error(Error::Type::ParserError, "Number encoding invalid.");
	}
}

void TestFileParser::Scanner::readStream(istream& _stream)
{
	std::string line;
	while (std::getline(_stream, line))
		m_line += line;
	m_char = m_line.begin();
}

void TestFileParser::Scanner::scanNextToken()
{
	// Make code coverage happy.
	assert(formatToken(Token::NUM_TOKENS) == "");

	auto detectKeyword = [](std::string const& _literal = "") -> TokenDesc {
		if (_literal == "ether") return TokenDesc{Token::Ether, _literal};
		if (_literal == "FAILURE") return TokenDesc{Token::Failure, _literal};
		return TokenDesc{Token::Identifier, _literal};
	};

	auto selectToken = [this](Token _token, std::string const& _literal = "") -> TokenDesc {
		advance();
		return make_pair(_token, !_literal.empty() ? _literal : formatToken(_token));
	};

	TokenDesc token = make_pair(Token::Unknown, "");
	do
	{
		switch(current())
		{
		case '/':
			advance();
			if (current() == '/')
				token = selectToken(Token::Newline);
			else
				token = selectToken(Token::Invalid);
			break;
		case '-':
			if (peek() == '>')
			{
				advance();
				token = selectToken(Token::Arrow);
			}
			else
				token = selectToken(Token::Sub);
			break;
		case ':':
			token = selectToken(Token::Colon);
			break;
		case '#':
			token = selectToken(Token::Comment, scanComment());
			break;
		case ',':
			token = selectToken(Token::Comma);
			break;
		case '(':
			token = selectToken(Token::LParen);
			break;
		case ')':
			token = selectToken(Token::RParen);
			break;
		default:
			if (isIdentifierStart(current()))
			{
				TokenDesc detectedToken = detectKeyword(scanIdentifierOrKeyword());
				token = selectToken(detectedToken.first, detectedToken.second);
			}
			else if (isdigit(current()))
				token = selectToken(Token::Number, scanNumber());
			else if (isspace(current()))
				token = selectToken(Token::Whitespace);
			else if (isEndOfLine())
				token = selectToken(Token::EOS);
			break;
		}
	}
	while (token.first == Token::Whitespace);
	m_currentToken = token;
}

string TestFileParser::Scanner::scanComment()
{
	string comment;
	advance();

	while (current() != '#')
	{
		comment += current();
		advance();
	}
	return comment;
}

string TestFileParser::Scanner::scanIdentifierOrKeyword()
{
	string identifier;
	identifier += current();
	while (isIdentifierPart(peek()))
	{
		advance();
		identifier += current();
	}
	return identifier;
}

string TestFileParser::Scanner::scanNumber()
{
	string number;
	number += current();
	while (isdigit(peek()))
	{
		advance();
		number += current();
	}
	return number;
}