#include <Python.h>

/* -*- Mode: C; c-file-style: "python" -*- */

#include <Python.h>
#include <locale.h>

/* ascii character tests (as opposed to locale tests) */
#define ISSPACE(c) ((c) == ' ' || (c) == '\f' || (c) == '\n' || \
(c) == '\r' || (c) == '\t' || (c) == '\v')
#define ISDIGIT(c) ((c) >= '0' && (c) <= '9')
#define ISXDIGIT(c) (ISDIGIT(c) || ((c) >= 'a' && (c) <= 'f') || ((c) >= 'A' && (c) <= 'F'))

/**
* PyOS_ascii_strtod:
* @nptr: the string to convert to a numeric value.
* @endptr: if non-%NULL, it returns the character after
* the last character used in the conversion.
*
* Converts a string to a #gdouble value.
* This function behaves like the standard strtod() function
* does in the C locale. It does this without actually
* changing the current locale, since that would not be
* thread-safe.
*
* This function is typically used when reading configuration
* files or other non-user input that should be locale independent.
* To handle input from the user you should normally use the
* locale-sensitive system strtod() function.
*
* If the correct value would cause overflow, plus or minus %HUGE_VAL
* is returned (according to the sign of the value), and %ERANGE is
* stored in %errno. If the correct value would cause underflow,
* zero is returned and %ERANGE is stored in %errno.
* If memory allocation fails, %ENOMEM is stored in %errno.
*
* This function resets %errno before calling strtod() so that
* you can reliably detect overflow and underflow.
*
* Return value: the #gdouble value.
**/
double
PyOS_ascii_strtod(const char *nptr, char **endptr)
{
char *fail_pos;
double val = -1.0;
struct lconv *locale_data;
const char *decimal_point;
size_t decimal_point_len;
const char *p, *decimal_point_pos;
const char *end = NULL; /* Silence gcc */

assert(nptr != NULL);

fail_pos = NULL;

locale_data = localeconv();
decimal_point = locale_data->decimal_point;
decimal_point_len = strlen(decimal_point);

assert(decimal_point_len != 0);

decimal_point_pos = NULL;
if (decimal_point[0] != '.' ||
decimal_point[1] != 0)
{
p = nptr;
/* Skip leading space */
while (ISSPACE(*p))
p++;

/* Skip leading optional sign */
if (*p == '+' || *p == '-')
p++;

while (ISDIGIT(*p))
p++;

if (*p == '.')
{
decimal_point_pos = p++;

while (ISDIGIT(*p))
p++;

if (*p == 'e' || *p == 'E')
p++;
if (*p == '+' || *p == '-')
p++;
while (ISDIGIT(*p))
p++;
end = p;
}
else if (strncmp(p, decimal_point, decimal_point_len) == 0)
{
/* Python bug #1417699 */
*endptr = (char*)nptr;
errno = EINVAL;
return val;
}
/* For the other cases, we need not convert the decimal point */
}

/* Set errno to zero, so that we can distinguish zero results
and underflows */
errno = 0;

if (decimal_point_pos)
{
char *copy, *c;

/* We need to convert the '.' to the locale specific decimal point */
copy = (char *)PyMem_MALLOC(end - nptr + 1 + decimal_point_len);
if (copy == NULL) {
if (endptr)
*endptr = (char *)nptr;
errno = ENOMEM;
return val;
}

c = copy;
memcpy(c, nptr, decimal_point_pos - nptr);
c += decimal_point_pos - nptr;
memcpy(c, decimal_point, decimal_point_len);
c += decimal_point_len;
memcpy(c, decimal_point_pos + 1, end - (decimal_point_pos + 1));
c += end - (decimal_point_pos + 1);
*c = 0;

val = strtod(copy, &fail_pos);

if (fail_pos)
{
if (fail_pos > decimal_point_pos)
fail_pos = (char *)nptr + (fail_pos - copy) - (decimal_point_len - 1);
else
fail_pos = (char *)nptr + (fail_pos - copy);
}

PyMem_FREE(copy);

}
else {
unsigned i = 0;
if (nptr[i] == '-')
i++;
if (nptr[i] == '0' && (nptr[i+1] == 'x' || nptr[i+1] == 'X'))
fail_pos = (char*)nptr;
else
val = strtod(nptr, &fail_pos);
}

if (endptr)
*endptr = fail_pos;

return val;
}

/**
* PyOS_ascii_formatd:
* @buffer: A buffer to place the resulting string in
* @buf_len: The length of the buffer.
* @format: The printf()-style format to use for the
* code to use for converting.
* @d: The #gdouble to convert
*
* Converts a #gdouble to a string, using the '.' as
* decimal point. To format the number you pass in
* a printf()-style format string. Allowed conversion
* specifiers are 'e', 'E', 'f', 'F', 'g' and 'G'.
*
* Return value: The pointer to the buffer with the converted string.
**/
char *
PyOS_ascii_formatd(char *buffer,
size_t buf_len,
const char *format,
double d)
{
struct lconv *locale_data;
const char *decimal_point;
size_t decimal_point_len, rest_len;
char *p;
char format_char;

/* g_return_val_if_fail (buffer != NULL, NULL); */
/* g_return_val_if_fail (format[0] == '%', NULL); */
/* g_return_val_if_fail (strpbrk (format + 1, "'l%") == NULL, NULL); */

format_char = format[strlen(format) - 1];

/* g_return_val_if_fail (format_char == 'e' || format_char == 'E' || */
/* format_char == 'f' || format_char == 'F' || */
/* format_char == 'g' || format_char == 'G', */
/* NULL); */

if (format[0] != '%')
return NULL;

if (strpbrk(format + 1, "'l%"))
return NULL;

if (!(format_char == 'e' || format_char == 'E' ||
format_char == 'f' || format_char == 'F' ||
format_char == 'g' || format_char == 'G'))
return NULL;

PyOS_snprintf(buffer, buf_len, format, d);

locale_data = localeconv();
decimal_point = locale_data->decimal_point;
decimal_point_len = strlen(decimal_point);

assert(decimal_point_len != 0);

if (decimal_point[0] != '.' ||
decimal_point[1] != 0)
{
p = buffer;

if (*p == '+' || *p == '-')
p++;

while (isdigit((unsigned char)*p))
p++;

if (strncmp(p, decimal_point, decimal_point_len) == 0)
{
*p = '.';
p++;
if (decimal_point_len > 1) {
rest_len = strlen(p + (decimal_point_len - 1));
memmove(p, p + (decimal_point_len - 1),
rest_len);
p[rest_len] = 0;
}
}
}

return buffer;
}

double
PyOS_ascii_atof(const char *nptr)
{
return PyOS_ascii_strtod(nptr, NULL);
}