CommonJS.h

/*
	This file is part of cpp-ethereum.

	cpp-ethereum 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.

	cpp-ethereum 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 cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
*/
/** @file CommonJS.h
 * @authors:
 *   Gav Wood <i@gavwood.com>
 *   Marek Kotewicz <marek@ethdev.com>
 * @date 2014
 */

#pragma once

#include <string>
#include "FixedHash.h"
#include "CommonData.h"
#include "CommonIO.h"

namespace dev
{

template <unsigned S> std::string toJS(FixedHash<S> const& _h)
{
	return "0x" + toHex(_h.ref());
}

template <unsigned N> std::string toJS(boost::multiprecision::number<boost::multiprecision::cpp_int_backend<N, N, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>> const& _n)
{
	std::string h = toHex(toCompactBigEndian(_n, 1));
	// remove first 0, if it is necessary;
	std::string res = h[0] != '0' ? h : h.substr(1);
	return "0x" + res;
}

inline std::string toJS(bytes const& _n, std::size_t _padding = 0)
{
	bytes n = _n;
	n.resize(std::max<unsigned>(n.size(), _padding));
	return "0x" + toHex(n);
}

template<unsigned T> std::string toJS(SecureFixedHash<T> const& _i)
{
	std::stringstream stream;
	stream << "0x" << _i.makeInsecure().hex();
	return stream.str();
}

template<typename T> std::string toJS(T const& _i)
{
	std::stringstream stream;
	stream << "0x" << std::hex << _i;
	return stream.str();
}

enum class OnFailed { InterpretRaw, Empty, Throw };

/// Convert string to byte array. Input parameter is hex, optionally prefixed by "0x".
/// Returns empty array if invalid input.
bytes jsToBytes(std::string const& _s, OnFailed _f = OnFailed::Empty);
/// Add '0' on, or remove items from, the front of @a _b until it is of length @a _l.
bytes padded(bytes _b, unsigned _l);
/// Add '0' on, or remove items from,  the back of @a _b until it is of length @a _l.
bytes paddedRight(bytes _b, unsigned _l);
/// Removing all trailing '0'. Returns empty array if input contains only '0' char.
bytes unpadded(bytes _s);
/// Remove all 0 byte on the head of @a _s.
bytes unpadLeft(bytes _s);
/// Convert h256 into user-readable string (by directly using std::string constructor). If it can't be interpreted as an ASCII string, empty string is returned.
std::string fromRaw(h256 _n);

template <unsigned N> FixedHash<N> jsToFixed(std::string const& _s)
{
	if (_s.substr(0, 2) == "0x")
		// Hex
		return FixedHash<N>(_s.substr(2 + std::max<unsigned>(N * 2, _s.size() - 2) - N * 2));
	else if (_s.find_first_not_of("0123456789") == std::string::npos)
		// Decimal
		return (typename FixedHash<N>::Arith)(_s);
	else
		// Binary
		return FixedHash<N>();	// FAIL
}

template <unsigned N> boost::multiprecision::number<boost::multiprecision::cpp_int_backend<N * 8, N * 8, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>> jsToInt(std::string const& _s)
{
	if (_s.substr(0, 2) == "0x")
		// Hex
		return fromBigEndian<boost::multiprecision::number<boost::multiprecision::cpp_int_backend<N * 8, N * 8, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>>(fromHex(_s.substr(2)));
	else if (_s.find_first_not_of("0123456789") == std::string::npos)
		// Decimal
		return boost::multiprecision::number<boost::multiprecision::cpp_int_backend<N * 8, N * 8, boost::multiprecision::unsigned_magnitude, boost::multiprecision::unchecked, void>>(_s);
	else
		// Binary
		return 0;			// FAIL
}

inline u256 jsToU256(std::string const& _s) { return jsToInt<32>(_s); }

/// Convert a string representation of a number to an int
/// String can be a normal decimal number, or a hex prefixed by 0x or 0X, or an octal if prefixed by 0
/// Returns 0 in case of failure
inline int jsToInt(std::string const& _s)
{
	int ret = 0;
	DEV_IGNORE_EXCEPTIONS(ret = std::stoi(_s, nullptr, 0));
	return ret;
}

inline std::string jsToDecimal(std::string const& _s)
{
	return toString(jsToU256(_s));
}

}