#include "jansson_private.h"

#include "strbuffer.h"

#include <assert.h>

#include <errno.h>

#include <math.h>

#include <stdio.h>

#include <string.h>

/* need jansson_private_config.h to get the correct snprintf */

#ifdef HAVE_CONFIG_H

#include <jansson_private_config.h>

#endif

#if JSON_HAVE_LOCALECONV

#include <locale.h>

/*

  - This code assumes that the decimal separator is exactly one

    character.

  - If setlocale() is called by another thread between the call to

    localeconv() and the call to sprintf() or strtod(), the result may

    be wrong. setlocale() is not thread-safe and should not be used

    this way. Multi-threaded programs should use uselocale() instead.

*/

static void to_locale(strbuffer_t *strbuffer) {

    const char *point;

    char *pos;

    point = localeconv()->decimal_point;

    if (*point == '.') {

        /* No conversion needed */

        return;

    }

    pos = strchr(strbuffer->value, '.');

    if (pos)

        *pos = *point;

}

static void from_locale(char *buffer) {

    const char *point;

    char *pos;

    point = localeconv()->decimal_point;

    if (*point == '.') {

        /* No conversion needed */

        return;

    }

    pos = strchr(buffer, *point);

    if (pos)

        *pos = '.';

}

#endif

int jsonp_strtod(strbuffer_t *strbuffer, double *out) {

    double value;

    char *end;

#if JSON_HAVE_LOCALECONV

    to_locale(strbuffer);

#endif

    errno = 0;

    value = strtod(strbuffer->value, &end);

    assert(end == strbuffer->value + strbuffer->length);

    if ((value == HUGE_VAL || value == -HUGE_VAL) && errno == ERANGE) {

        /* Overflow */

        return -1;

    }

    *out = value;

    return 0;

}

int jsonp_dtostr(char *buffer, size_t size, double value, int precision) {

    int ret;

    char *start, *end;

    size_t length;

    if (precision == 0)

        precision = 17;

    ret = snprintf(buffer, size, "%.*g", precision, value);

    if (ret < 0)

        return -1;

    length = (size_t)ret;

    if (length >= size)

        return -1;

#if JSON_HAVE_LOCALECONV

    from_locale(buffer);

#endif

    /* Make sure there's a dot or 'e' in the output. Otherwise

       a real is converted to an integer when decoding */

    if (strchr(buffer, '.') == NULL && strchr(buffer, 'e') == NULL) {

        if (length + 3 >= size) {

            /* No space to append ".0" */

            return -1;

        }

        buffer[length] = '.';

        buffer[length + 1] = '0';

        buffer[length + 2] = '\0';

        length += 2;

    }

    /* Remove leading '+' from positive exponent. Also remove leading

       zeros from exponents (added by some printf() implementations) */

    start = strchr(buffer, 'e');

    if (start) {

        start++;

        end = start + 1;

        if (*start == '-')

            start++;

        while (*end == '0')

            end++;

        if (end != start) {

            memmove(start, end, length - (size_t)(end - buffer));

            length -= (size_t)(end - start);

        }

    }

    return (int)length;

}