/*
 * Copyright (C) 2020 Emeric Poupon
 *
 * This file is part of LMS.
 *
 * LMS 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.
 *
 * LMS 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 LMS.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "utils/String.hpp"

#include <algorithm>
#include <iomanip>
#include <unordered_map>

#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/join.hpp>
#include <boost/algorithm/string.hpp>

namespace StringUtils {

bool
readList(const std::string& str, const std::string& separators, std::list<std::string>& results)
{
	std::string curStr;

	for (char c : str)
	{
		if (separators.find(c) != std::string::npos) {
			if (!curStr.empty()) {
				results.push_back(curStr);
				curStr.clear();
			}
		}
		else {
			if (curStr.empty() && std::isspace(c))
				continue;

			curStr.push_back(c);
		}
	}

	if (!curStr.empty())
		results.push_back(curStr);

	return !str.empty();
}

template<>
std::optional<std::string>
readAs(std::string_view str)
{
	return std::string {str};
}

template<>
std::optional<bool>
readAs(std::string_view str)
{
	if (str == "1" || str == "true")
		return true;
	else if (str == "0" || str == "false")
		return false;

	return std::nullopt;
}

std::vector<std::string>
splitStringCopy(std::string_view string, std::string_view separators)
{
	std::string str {stringTrim(string, separators)};

	std::vector<std::string> res;
	boost::algorithm::split(res, str, boost::is_any_of(separators), boost::token_compress_on);

	return res;
}

std::vector<std::string_view>
splitString(std::string_view str, std::string_view separators)
{
	std::vector<std::string_view> res;

	std::string_view::size_type strBegin {};

	while ((strBegin = str.find_first_not_of(separators, strBegin)) != std::string_view::npos)
	{
		auto strEnd {str.find_first_of(separators, strBegin + 1)};
		if (strEnd == std::string_view::npos)
		{
			res.push_back(str.substr(strBegin, str.size() - strBegin));
			break;
		}

		res.push_back(str.substr(strBegin, strEnd - strBegin));
		strBegin = strEnd + 1;
	}

	return res;
}

std::string
joinStrings(const std::vector<std::string>& strings, const std::string& delimiter)
{
	return boost::algorithm::join(strings, delimiter);
}

std::string_view
stringTrim(std::string_view str, std::string_view whitespaces)
{
	std::string_view res;

	const auto strBegin = str.find_first_not_of(whitespaces);
	if (strBegin != std::string_view::npos)
	{
		const auto strEnd {str.find_last_not_of(whitespaces)};
		const auto strRange {strEnd - strBegin + 1};

		res = str.substr(strBegin, strRange);
	}

	return res;
}

std::string_view
stringTrimEnd(std::string_view str, std::string_view whitespaces)
{
	return str.substr(0, str.find_last_not_of(whitespaces) + 1);
}

std::string
stringToLower(std::string_view str)
{
	std::string res;
	res.reserve(str.size());

	std::transform(std::cbegin(str), std::cend(str), std::back_inserter(res), [](unsigned char c) { return std::tolower(c);});

	return res;
}

void
stringToLower(std::string& str)
{
	std::transform(std::cbegin(str), std::cend(str), std::begin(str), [](unsigned char c) { return std::tolower(c);});
}

std::string
stringToUpper(const std::string& str)
{
	std::string res;
	res.reserve(str.size());

	std::transform(std::cbegin(str), std::cend(str), std::back_inserter(res), [](char c) { return std::toupper(c);});

	return res;
}

std::string
bufferToString(const std::vector<unsigned char>& data)
{
	std::ostringstream oss;

	for (unsigned char c : data)
	{
		oss << std::setw(2) << std::setfill('0') << std::hex << (int)c;
	}

	return oss.str();
}

void
capitalize(std::string& str)
{
	for (auto it {std::begin(str)}; it != std::end(str); ++it)
	{
		if (std::isspace(*it))
			continue;

		if (std::isalpha(*it))
			*it = std::toupper(*it);

		break;
	}
}

std::string
replaceInString(std::string_view str, const std::string& from, const std::string& to)
{
	std::string res {str};
	size_t pos = 0;

	while ((pos = res.find(from, pos)) != std::string::npos)
	{
		res.replace(pos, from.length(), to);
		pos += to.length();
	}

	return res;
}

std::string
jsEscape(const std::string& str)
{
	static const std::unordered_map<char, std::string_view> escapeMap
	{
		{ '\\', "\\\\" },
		{ '\n', "\\n" },
		{ '\r', "\\r" },
		{ '\t', "\\t" },
		{ '"', "\\\"" },
		{ '\'', "\\\'" },
	};

	std::string escaped;
	escaped.reserve(str.length());

	for (const char c : str)
	{
		auto it {escapeMap.find(c)};
		if (it == std::cend(escapeMap))
		{
			escaped += c;
			continue;
		}

		escaped += it->second;
	}

	return escaped;
}

std::string
escapeString(std::string_view str, std::string_view charsToEscape, char escapeChar)
{
	std::string res;
	res.reserve(str.size());

	for (const char c : str)
	{
		if (std::any_of(std::cbegin(charsToEscape), std::cend(charsToEscape), [c](char charToEscape) { return c == charToEscape; }))
			res += escapeChar;

		res += c;
	}

	return res;
}

bool
stringEndsWith(const std::string& str, const std::string& ending)
{
	return boost::algorithm::ends_with(str, ending);
}

std::optional<std::string>
stringFromHex(const std::string& str)
{
	static const char lut[] {"0123456789ABCDEF"};

	if (str.length() % 2 != 0)
		return std::nullopt;

	std::string res;
	res.reserve(str.length() / 2);

	auto it {std::cbegin(str)};
	while (it != std::cend(str))
	{
		unsigned val {};

		auto itHigh {std::lower_bound(std::cbegin(lut), std::cend(lut), std::toupper(*(it++)))};
		auto itLow {std::lower_bound(std::cbegin(lut), std::cend(lut), std::toupper(*(it++)))};

		if (itHigh == std::cend(lut) || itLow == std::cend(lut))
			return {};

		val = std::distance(std::cbegin(lut), itHigh) << 4;
		val += std::distance(std::cbegin(lut), itLow );

		res.push_back(static_cast<char>(val));
	}

	return res;
}

} // StringUtils