/**
 * strings.cpp: Useful functions for manipulating strings
 **/
#include "core/strings.h"
#include "core/session.h" // locale

#include <QByteArray>
#include <QDebug>
#include <QLocale>
#include <QString>
#include <QTextDocument>

#include <algorithm>
#include <cctype>
#include <codecvt>
#include <iostream>
#include <iomanip>
#include <locale>
#include <string>
#include <unordered_map>
#include <vector>

#include "utf8proc.h"

namespace Strings {

/* ew */
std::string Implode(const std::vector<std::string>& vector, const std::string& delimiter) {
	if (vector.size() < 1)
		return "";

	std::string out;

	for (unsigned long long i = 0; i < vector.size(); i++) {
		out.append(vector.at(i));
		if (i < vector.size() - 1)
			out.append(delimiter);
	}

	return out;
}

std::vector<std::string> Split(const std::string& text, const std::string& delimiter) {
	if (text.length() < 1)
		return {};

	std::vector<std::string> tokens;

	std::size_t start = 0, end = 0;
	while ((end = text.find(delimiter, start)) != std::string::npos) {
		tokens.push_back(text.substr(start, end - start));
		start = end + delimiter.length();
	}
	tokens.push_back(text.substr(start));

	return tokens;
}

/* This function is really only used for cleaning up the synopsis of
 * horrible HTML debris from AniList :)
 */
void ReplaceAll(std::string& string, std::string_view find, std::string_view replace) {
	size_t pos = 0;
	while ((pos = string.find(find, pos)) != std::string::npos) {
		string.replace(pos, find.length(), replace);
		pos += replace.length();
	}
}

void SanitizeLineEndings(std::string& string) {
	/* LOL */
	ReplaceAll(string, "\r\n",   "\n");
	ReplaceAll(string, "</p>",   "\n");
	ReplaceAll(string, "<br>",   "\n");
	ReplaceAll(string, "<br />", "\n");
	ReplaceAll(string, "\n\n\n", "\n\n");
}

void ConvertRomanNumerals(std::string& string) {
	static const std::vector<std::pair<std::string_view, std::string_view>> vec = {
		{"2", "II"}, {"3", "III"}, {"4", "IV"}, {"5", "V"}, {"6", "VI"},
		{"7", "VII"}, {"8", "VIII"}, {"9", "IX"}, {"11", "XI"}, {"12", "XII"},
		{"13", "XIII"}
	};

	for (const auto& item : vec)
		ReplaceAll(string, item.second, item.first);
}

/* this also performs case folding, so our string is lowercase after this */
void NormalizeUnicode(std::string& string) {
	static constexpr utf8proc_option_t options = static_cast<utf8proc_option_t>(
		UTF8PROC_COMPAT | UTF8PROC_COMPOSE | UTF8PROC_STABLE |
		UTF8PROC_IGNORE | UTF8PROC_STRIPCC | UTF8PROC_STRIPMARK |
		UTF8PROC_LUMP | UTF8PROC_CASEFOLD | UTF8PROC_NLF2LS
	);

	/* ack */
	utf8proc_uint8_t* buf = nullptr;

	const utf8proc_ssize_t size = utf8proc_map(
		reinterpret_cast<const utf8proc_uint8_t*>(string.data()),
		string.size(),
		&buf,
		options
	);

	if (size)
		string = std::string(reinterpret_cast<const char*>(buf), size);

	if (buf)
		free(buf);
}

void NormalizeAnimeTitle(std::string& string) {
	ConvertRomanNumerals(string);
	NormalizeUnicode(string);
	RemoveLeadingChars(string, ' ');
	RemoveTrailingChars(string, ' ');
}

/* removes dumb HTML tags because anilist is aids and
 * gives us HTML for synopses :/
 */
void RemoveHtmlTags(std::string& string) {
	while (string.find("<") != std::string::npos) {
		auto startpos = string.find("<");
		auto endpos = string.find(">") + 1;

		if (endpos != std::string::npos)
			string.erase(startpos, endpos - startpos);
	}
}

/* e.g. "&lt;" for "<" */
void ParseHtmlEntities(std::string& string) {
	const std::unordered_map<std::string, std::string> map = {
	    {"&lt;",    "<"},
        {"&rt;",    ">"},
        {"&nbsp;",  "\xA0"},
        {"&amp;",   "&"},
        {"&quot;",  "\""},
	    {"&apos;",  "'"},
        {"&cent;",  "¢"},
        {"&pound;", "£"},
        {"&euro;",  "€"},
        {"&yen;",   "¥"},
	    {"&copy;",  "©"},
        {"&reg;",   "®"},
        {"&times;", "×"},
        {"&rsquo;", "’" }  // Haibane Renmei, AniList
	};

	for (const auto& item : map)
		ReplaceAll(string, item.first, item.second);
}

/* removes stupid HTML stuff */
void TextifySynopsis(std::string& string) {
#if 1
	/* Just let Qt deal with it. */
	QTextDocument text;
	text.setHtml(Strings::ToQString(string));
	string = Strings::ToUtf8String(text.toPlainText());
#else
	/* old implementation here... beware of jankiness */
	SanitizeLineEndings(string);
	RemoveHtmlTags(string);
	ParseHtmlEntities(string);
#endif
}

/* let Qt handle the heavy lifting of locale shit
 * I don't want to deal with
 */
std::string ToUpper(const std::string& string) {
	return ToUtf8String(session.config.locale.GetLocale().toUpper(ToQString(string)));
}

std::string ToLower(const std::string& string) {
	return ToUtf8String(session.config.locale.GetLocale().toLower(ToQString(string)));
}

std::wstring ToWstring(const std::string& string) {
	static std::wstring_convert<std::codecvt_utf8<wchar_t>> converter("", L"");

	std::wstring wstr;
	try {
		wstr = converter.from_bytes(string);
	} catch (std::range_error const& ex) {
		std::cerr << "Failed to convert UTF-8 to wide string!" << std::endl;
	}
	return wstr;
}

std::wstring ToWstring(const QString& string) {
	std::wstring arr(string.size(), L'\0');
	string.toWCharArray(&arr.front());
	return arr;
}

std::string ToUtf8String(const std::wstring& wstring) {
	static std::wstring_convert<std::codecvt_utf8<wchar_t>> converter("", L"");
	return converter.to_bytes(wstring);
}

std::string ToUtf8String(const QString& string) {
	const QByteArray ba = string.toUtf8();
	return std::string(ba.constData(), ba.size());
}

std::string ToUtf8String(const QByteArray& ba) {
	return std::string(ba.constData(), ba.size());
}

QString ToQString(const std::string& string) {
	return QString::fromUtf8(string.c_str(), string.length());
}

QString ToQString(const std::wstring& wstring) {
	return QString::fromWCharArray(wstring.c_str(), wstring.length());
}

std::string ToUtf8String(const bool b) {
	return b ? "true" : "false"; // lol
}

bool ToBool(const std::string& str, bool def) {
	std::istringstream s(Strings::ToLower(str));
	s >> std::boolalpha >> def;
	return def;
}

/* util funcs */
uint64_t HumanReadableSizeToBytes(const std::string& str) {
	static const std::unordered_map<std::string, uint64_t> bytes_map = {
		{"KB", 1000ull},
		{"MB", 1000000ull},
		{"GB", 1000000000ull},
		{"TB", 1000000000000ull},
		{"PB", 1000000000000000ull},
	    {"KiB", 1ull << 10},
	    {"MiB", 1ull << 20},
	    {"GiB", 1ull << 30},
	    {"TiB", 1ull << 40},
	    {"PiB", 1ull << 50}  /* surely we won't need more than this */
	};

	for (const auto& suffix : bytes_map) {
		if (str.find(suffix.first) != std::string::npos) {
			try {
				uint64_t size = std::stod(str) * suffix.second;
				return size;
			} catch (std::invalid_argument const& ex) {
				continue;
			}
		}
	}

	return ToInt(str, 0);
}

std::string BytesToHumanReadableSize(uint64_t bytes, int precision) {
#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
	/* QLocale in Qt >= 5.10.0 has a function for this */
	return Strings::ToUtf8String(session.config.locale.GetLocale().formattedDataSize(bytes, precision));
#else
	static const std::unordered_map<uint64_t, std::string> map = {
		{1ull << 10, "KiB"},
		{1ull << 20, "MiB"},
		{1ull << 30, "GiB"},
		{1ull << 40, "TiB"},
		{1ull << 50, "PiB"}
	};

	for (const auto& suffix : map) {
		if (bytes / suffix.first < 1)
			continue;

		std::stringstream ss;
		ss << std::setprecision(precision)
		   << (static_cast<double>(bytes) / suffix.first) << " "
		   << suffix.second;
		return ss.str();
	}

	/* better luck next time */
	return "0 bytes";
#endif
}

void RemoveLeadingChars(std::string& s, const char c) {
	s.erase(0, std::min(s.find_first_not_of(c), s.size() - 1));
}

void RemoveTrailingChars(std::string& s, const char c) {
	s.erase(s.find_last_not_of(c) + 1, std::string::npos);
}

bool BeginningMatchesSubstring(const std::string& str, const std::string& sub) {
	for (unsigned long long i = 0; i < str.length() && i < sub.length(); i++)
		if (str[i] != sub[i])
			return false;

	return true;
}

} // namespace Strings