/*
	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 Common.cpp
 * @author Gav Wood <i@gavwood.com>
 * @date 2014
 */

#include "CommonData.h"

#include <random>
#include "Exceptions.h"
#include <libdevcore/Log.h>
using namespace std;
using namespace dev;

std::string dev::escaped(std::string const& _s, bool _all)
{
	static const map<char, char> prettyEscapes{{'\r', 'r'}, {'\n', 'n'}, {'\t', 't'}, {'\v', 'v'}};
	std::string ret;
	ret.reserve(_s.size() + 2);
	ret.push_back('"');
	for (auto i: _s)
		if (i == '"' && !_all)
			ret += "\\\"";
		else if (i == '\\' && !_all)
			ret += "\\\\";
		else if (prettyEscapes.count(i))
		{
			ret += '\\';
			ret += prettyEscapes.find(i)->second;
		}
		else if (i < ' ' || _all)
		{
			ret += "\\x";
			ret.push_back("0123456789abcdef"[(uint8_t)i / 16]);
			ret.push_back("0123456789abcdef"[(uint8_t)i % 16]);
		}
		else
			ret.push_back(i);
	ret.push_back('"');
	return ret;
}

std::string dev::randomWord()
{
	static std::mt19937_64 s_eng(0);
	std::string ret(std::uniform_int_distribution<int>(1, 5)(s_eng), ' ');
	char const n[] = "qwertyuiop";//asdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM1234567890";
	std::uniform_int_distribution<int> d(0, sizeof(n) - 2);
	for (char& c: ret)
		c = n[d(s_eng)];
	return ret;
}

int dev::fromHex(char _i)
{
	if (_i >= '0' && _i <= '9')
		return _i - '0';
	if (_i >= 'a' && _i <= 'f')
		return _i - 'a' + 10;
	if (_i >= 'A' && _i <= 'F')
		return _i - 'A' + 10;
	BOOST_THROW_EXCEPTION(BadHexCharacter() << errinfo_invalidSymbol(_i));
}

bytes dev::fromHex(std::string const& _s)
{
	unsigned s = (_s[0] == '0' && _s[1] == 'x') ? 2 : 0;
	std::vector<uint8_t> ret;
	ret.reserve((_s.size() - s + 1) / 2);

	if (_s.size() % 2)
		try
		{
			ret.push_back(fromHex(_s[s++]));
		}
		catch (...){ ret.push_back(0); cwarn << boost::current_exception_diagnostic_information(); }
	for (unsigned i = s; i < _s.size(); i += 2)
		try
		{
			ret.push_back((byte)(fromHex(_s[i]) * 16 + fromHex(_s[i + 1])));
		}
		catch (...){ ret.push_back(0); cwarn << boost::current_exception_diagnostic_information(); }
	return ret;
}

bytes dev::asNibbles(std::string const& _s)
{
	std::vector<uint8_t> ret;
	ret.reserve(_s.size() * 2);
	for (auto i: _s)
	{
		ret.push_back(i / 16);
		ret.push_back(i % 16);
	}
	return ret;
}

#if 0

/* Following code is copyright 2012-2014 Luke Dashjr
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the standard MIT license.  See COPYING for more details.
 */

#include <cstdbool>
#include <cstddef>
#include <cstdint>
#include <cstring>

static const int8_t b58digits_map[] = {
	-1,-1,-1,-1,-1,-1,-1,-1, -1,-1,-1,-1,-1,-1,-1,-1,
	-1,-1,-1,-1,-1,-1,-1,-1, -1,-1,-1,-1,-1,-1,-1,-1,
	-1,-1,-1,-1,-1,-1,-1,-1, -1,-1,-1,-1,-1,-1,-1,-1,
	-1, 0, 1, 2, 3, 4, 5, 6,  7, 8,-1,-1,-1,-1,-1,-1,
	-1, 9,10,11,12,13,14,15, 16,-1,17,18,19,20,21,-1,
	22,23,24,25,26,27,28,29, 30,31,32,-1,-1,-1,-1,-1,
	-1,33,34,35,36,37,38,39, 40,41,42,43,-1,44,45,46,
	47,48,49,50,51,52,53,54, 55,56,57,-1,-1,-1,-1,-1,
};

bool b58tobin(void *bin, size_t *binszp, const char *b58, size_t b58sz)
{
	size_t binsz = *binszp;
	const unsigned char *b58u = (void*)b58;
	unsigned char *binu = bin;
	size_t outisz = (binsz + 3) / 4;
	uint32_t outi[outisz];
	uint64_t t;
	uint32_t c;
	size_t i, j;
	uint8_t bytesleft = binsz % 4;
	uint32_t zeromask = bytesleft ? (0xffffffff << (bytesleft * 8)) : 0;
	unsigned zerocount = 0;

	if (!b58sz)
		b58sz = strlen(b58);

	memset(outi, 0, outisz * sizeof(*outi));

	// Leading zeros, just count
	for (i = 0; i < b58sz && !b58digits_map[b58u[i]]; ++i)
		++zerocount;

	for ( ; i < b58sz; ++i)
	{
		if (b58u[i] & 0x80)
			// High-bit set on invalid digit
			return false;
		if (b58digits_map[b58u[i]] == -1)
			// Invalid base58 digit
			return false;
		c = (unsigned)b58digits_map[b58u[i]];
		for (j = outisz; j--; )
		{
			t = ((uint64_t)outi[j]) * 58 + c;
			c = (t & 0x3f00000000) >> 32;
			outi[j] = t & 0xffffffff;
		}
		if (c)
			// Output number too big (carry to the next int32)
			return false;
		if (outi[0] & zeromask)
			// Output number too big (last int32 filled too far)
			return false;
	}

	j = 0;
	switch (bytesleft) {
		case 3:
			*(binu++) = (outi[0] &   0xff0000) >> 16;
		case 2:
			*(binu++) = (outi[0] &     0xff00) >>  8;
		case 1:
			*(binu++) = (outi[0] &       0xff);
			++j;
		default:
			break;
	}

	for (; j < outisz; ++j)
	{
		*(binu++) = (outi[j] >> 0x18) & 0xff;
		*(binu++) = (outi[j] >> 0x10) & 0xff;
		*(binu++) = (outi[j] >>    8) & 0xff;
		*(binu++) = (outi[j] >>    0) & 0xff;
	}

	// Count canonical base58 byte count
	binu = bin;
	for (i = 0; i < binsz; ++i)
	{
		if (binu[i])
			break;
		--*binszp;
	}
	*binszp += zerocount;

	return true;
}

static
bool my_dblsha256(void *hash, const void *data, size_t datasz)
{
	uint8_t buf[0x20];
	return b58_sha256_impl(buf, data, datasz) && b58_sha256_impl(hash, buf, sizeof(buf));
}

int b58check(const void *bin, size_t binsz, const char *base58str, size_t b58sz)
{
	unsigned char buf[32];
	const uint8_t *binc = bin;
	unsigned i;
	if (binsz < 4)
		return -4;
	if (!my_dblsha256(buf, bin, binsz - 4))
		return -2;
	if (memcmp(&binc[binsz - 4], buf, 4))
		return -1;

	// Check number of zeros is correct AFTER verifying checksum (to avoid possibility of accessing base58str beyond the end)
	for (i = 0; binc[i] == '\0' && base58str[i] == '1'; ++i)
	{}  // Just finding the end of zeros, nothing to do in loop
	if (binc[i] == '\0' || base58str[i] == '1')
		return -3;

	return binc[0];
}

static const char b58digits_ordered[] = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";

bool b58enc(char *b58, size_t *b58sz, const void *data, size_t binsz)
{
	const uint8_t *bin = data;
	int carry;
	size_t i, j, high, zcount = 0;
	size_t size;

	while (zcount < binsz && !bin[zcount])
		++zcount;

	size = (binsz - zcount) * 138 / 100 + 1;
	uint8_t buf[size];
	memset(buf, 0, size);

	for (i = zcount, high = size - 1; i < binsz; ++i, high = j)
	{
		for (carry = bin[i], j = size - 1; (j > high) || carry; --j)
		{
			carry += 256 * buf[j];
			buf[j] = carry % 58;
			carry /= 58;
		}
	}

	for (j = 0; j < size && !buf[j]; ++j);

	if (*b58sz <= zcount + size - j)
	{
		*b58sz = zcount + size - j + 1;
		return false;
	}

	if (zcount)
		memset(b58, '1', zcount);
	for (i = zcount; j < size; ++i, ++j)
		b58[i] = b58digits_ordered[buf[j]];
	b58[i] = '\0';
	*b58sz = i + 1;

	return true;
}

#endif