// SPDX-License-Identifier: GPL-2.0-or-later

#include "image_int.hpp"

#include <cstdarg>
#include <cstddef>
#include <cstring>
#include <cstdio>

namespace Exiv2::Internal {
    std::string stringFormat(const char* format, ...)
    {
        std::string result;
        std::vector<char> buffer;
        size_t need = std::strlen(format) * 8;  // initial guess
        int rc = -1;

        // vsnprintf writes at most size (2nd parameter) bytes (including \0)
        //           returns the number of bytes required for the formatted string excluding \0
        // the following loop goes through:
        // one iteration (if 'need' was large enough for the for formatted string)
        // or two iterations (after the first call to vsnprintf we know the required length)
        do {
            buffer.resize(need + 1);
            va_list args;            // variable arg list
            va_start(args, format);  // args start after format
            rc = vsnprintf(&buffer[0], buffer.size(), format, args);
            va_end(args);     // free the args
            assert(rc >= 0);  // rc < 0 => we have made an error in the format string
            if (rc > 0)
                need = static_cast<size_t>(rc);
        } while (buffer.size() <= need);

        if (rc > 0)
            result = std::string(&buffer[0], need);
        return result;
    }

    std::string indent(int32_t d)
    {
        std::string result;
        if (d > 0)
            while (d--)
                result += "  ";
        return result;
    }

}  // namespace Exiv2::Internal