//              Copyright Catch2 Authors
// Distributed under the Boost Software License, Version 1.0.
//   (See accompanying file LICENSE.txt or copy at
//        https://www.boost.org/LICENSE_1_0.txt)

// SPDX-License-Identifier: BSL-1.0

#include <catch2/catch_tostring.hpp>
#include <catch2/interfaces/catch_interfaces_config.hpp>
#include <catch2/interfaces/catch_interfaces_registry_hub.hpp>
#include <catch2/internal/catch_context.hpp>
#include <catch2/internal/catch_polyfills.hpp>

#include <iomanip>

namespace Catch {

namespace Detail {

    namespace {
        const int hexThreshold = 255;

        struct Endianness {
            enum Arch : uint8_t {
                Big,
                Little
            };

            static Arch which() {
                int one = 1;
                // If the lowest byte we read is non-zero, we can assume
                // that little endian format is used.
                auto value = *reinterpret_cast<char*>(&one);
                return value ? Little : Big;
            }
        };

        template<typename T>
        std::string fpToString(T value, int precision) {
            if (Catch::isnan(value)) {
                return "nan";
            }

            ReusableStringStream rss;
            rss << std::setprecision(precision)
                << std::fixed
                << value;
            std::string d = rss.str();
            std::size_t i = d.find_last_not_of('0');
            if (i != std::string::npos && i != d.size() - 1) {
                if (d[i] == '.')
                    i++;
                d = d.substr(0, i + 1);
            }
            return d;
        }
    } // end unnamed namespace

    std::size_t catch_strnlen( const char* str, std::size_t n ) {
        auto ret = std::char_traits<char>::find( str, n, '\0' );
        if ( ret != nullptr ) { return static_cast<std::size_t>( ret - str ); }
        return n;
    }

    std::string formatTimeT(std::time_t time) {
#ifdef _MSC_VER
        std::tm timeInfo = {};
        const auto err = gmtime_s( &timeInfo, &time );
        if ( err ) {
            return "gmtime from provided timepoint has failed. This "
                   "happens e.g. with pre-1970 dates using Microsoft libc";
        }
#else
        std::tm* timeInfo = std::gmtime( &time );
#endif

        auto const timeStampSize = sizeof( "2017-01-16T17:06:45Z" );
        char timeStamp[timeStampSize];
        const char* const fmt = "%Y-%m-%dT%H:%M:%SZ";

#ifdef _MSC_VER
        std::strftime( timeStamp, timeStampSize, fmt, &timeInfo );
#else
        std::strftime( timeStamp, timeStampSize, fmt, timeInfo );
#endif
        return std::string( timeStamp, timeStampSize - 1 );
    }

    std::string convertIntoString(StringRef string, bool escapeInvisibles) {
        std::string ret;
        // This is enough for the "don't escape invisibles" case, and a good
        // lower bound on the "escape invisibles" case.
        ret.reserve( string.size() + 2 );

        if ( !escapeInvisibles ) {
            ret += '"';
            ret += string;
            ret += '"';
            return ret;
        }

        size_t last_start = 0;
        auto write_to = [&]( size_t idx ) {
            if ( last_start < idx ) {
                ret += string.substr( last_start, idx - last_start );
            }
            last_start = idx + 1;
        };

        ret += '"';
        for ( size_t i = 0; i < string.size(); ++i ) {
            const char c = string[i];
            if ( c == '\r' || c == '\n' || c == '\t' || c == '\f' ) {
                write_to( i );
                if ( c == '\r' ) { ret.append( "\\r" ); }
                if ( c == '\n' ) { ret.append( "\\n" ); }
                if ( c == '\t' ) { ret.append( "\\t" ); }
                if ( c == '\f' ) { ret.append( "\\f" ); }
            }
        }
        write_to( string.size() );
        ret += '"';

        return ret;
    }

    std::string convertIntoString(StringRef string) {
        return convertIntoString(string, getCurrentContext().getConfig()->showInvisibles());
    }

    std::string rawMemoryToString( const void *object, std::size_t size ) {
        // Reverse order for little endian architectures
        int i = 0, end = static_cast<int>( size ), inc = 1;
        if( Endianness::which() == Endianness::Little ) {
            i = end-1;
            end = inc = -1;
        }

        unsigned char const *bytes = static_cast<unsigned char const *>(object);
        ReusableStringStream rss;
        rss << "0x" << std::setfill('0') << std::hex;
        for( ; i != end; i += inc )
             rss << std::setw(2) << static_cast<unsigned>(bytes[i]);
       return rss.str();
    }

    std::string makeExceptionHappenedString() {
        return "{ stringification failed with an exception: \"" +
               translateActiveException() + "\" }";

    }

} // end Detail namespace



//// ======================================================= ////
//
//   Out-of-line defs for full specialization of StringMaker
//
//// ======================================================= ////

std::string StringMaker<std::string>::convert(const std::string& str) {
    return Detail::convertIntoString( str );
}

#ifdef CATCH_CONFIG_CPP17_STRING_VIEW
std::string StringMaker<std::string_view>::convert(std::string_view str) {
    return Detail::convertIntoString( StringRef( str.data(), str.size() ) );
}
#endif

std::string StringMaker<char const*>::convert(char const* str) {
    if (str) {
        return Detail::convertIntoString( str );
    } else {
        return{ "{null string}" };
    }
}
std::string StringMaker<char*>::convert(char* str) { // NOLINT(readability-non-const-parameter)
    if (str) {
        return Detail::convertIntoString( str );
    } else {
        return{ "{null string}" };
    }
}

#ifdef CATCH_CONFIG_WCHAR
std::string StringMaker<std::wstring>::convert(const std::wstring& wstr) {
    std::string s;
    s.reserve(wstr.size());
    for (auto c : wstr) {
        s += (c <= 0xff) ? static_cast<char>(c) : '?';
    }
    return ::Catch::Detail::stringify(s);
}

# ifdef CATCH_CONFIG_CPP17_STRING_VIEW
std::string StringMaker<std::wstring_view>::convert(std::wstring_view str) {
    return StringMaker<std::wstring>::convert(std::wstring(str));
}
# endif

std::string StringMaker<wchar_t const*>::convert(wchar_t const * str) {
    if (str) {
        return ::Catch::Detail::stringify(std::wstring{ str });
    } else {
        return{ "{null string}" };
    }
}
std::string StringMaker<wchar_t *>::convert(wchar_t * str) {
    if (str) {
        return ::Catch::Detail::stringify(std::wstring{ str });
    } else {
        return{ "{null string}" };
    }
}
#endif

#if defined(CATCH_CONFIG_CPP17_BYTE)
#include <cstddef>
std::string StringMaker<std::byte>::convert(std::byte value) {
    return ::Catch::Detail::stringify(std::to_integer<unsigned long long>(value));
}
#endif // defined(CATCH_CONFIG_CPP17_BYTE)

std::string StringMaker<int>::convert(int value) {
    return ::Catch::Detail::stringify(static_cast<long long>(value));
}
std::string StringMaker<long>::convert(long value) {
    return ::Catch::Detail::stringify(static_cast<long long>(value));
}
std::string StringMaker<long long>::convert(long long value) {
    ReusableStringStream rss;
    rss << value;
    if (value > Detail::hexThreshold) {
        rss << " (0x" << std::hex << value << ')';
    }
    return rss.str();
}

std::string StringMaker<unsigned int>::convert(unsigned int value) {
    return ::Catch::Detail::stringify(static_cast<unsigned long long>(value));
}
std::string StringMaker<unsigned long>::convert(unsigned long value) {
    return ::Catch::Detail::stringify(static_cast<unsigned long long>(value));
}
std::string StringMaker<unsigned long long>::convert(unsigned long long value) {
    ReusableStringStream rss;
    rss << value;
    if (value > Detail::hexThreshold) {
        rss << " (0x" << std::hex << value << ')';
    }
    return rss.str();
}

std::string StringMaker<signed char>::convert(signed char value) {
    if (value == '\r') {
        return "'\\r'";
    } else if (value == '\f') {
        return "'\\f'";
    } else if (value == '\n') {
        return "'\\n'";
    } else if (value == '\t') {
        return "'\\t'";
    } else if ('\0' <= value && value < ' ') {
        return ::Catch::Detail::stringify(static_cast<unsigned int>(value));
    } else {
        char chstr[] = "' '";
        chstr[1] = value;
        return chstr;
    }
}
std::string StringMaker<char>::convert(char c) {
    return ::Catch::Detail::stringify(static_cast<signed char>(c));
}
std::string StringMaker<unsigned char>::convert(unsigned char value) {
    return ::Catch::Detail::stringify(static_cast<char>(value));
}

int StringMaker<float>::precision = std::numeric_limits<float>::max_digits10;

std::string StringMaker<float>::convert(float value) {
    return Detail::fpToString(value, precision) + 'f';
}

int StringMaker<double>::precision = std::numeric_limits<double>::max_digits10;

std::string StringMaker<double>::convert(double value) {
    return Detail::fpToString(value, precision);
}

} // end namespace Catch