/*
 * Copyright (c) 2021 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "secinput.h"

static size_t SecWcslen(const wchar_t *s)
{
    const wchar_t *end = s;
    while (*end != L'\0') {
        ++end;
    }
    return ((size_t)((end - s)));
}

/*******************************************************************************
 * <FUNCTION DESCRIPTION>
 *    The  vswscanf_s  function  is  the  wide-character  equivalent  of the vsscanf_s function
 *    The vsscanf_s function reads data from buffer into the location given by
 *    each argument. Every argument must be a pointer to a variable with a type
 *    that corresponds to a type specifier in format.
 *    The format argument controls the interpretation of the input fields and
 *    has the same form and function as the format argument for the scanf function.
 *    If copying takes place between strings that overlap, the behavior is undefined.
 *
 * <INPUT PARAMETERS>
 *    buffer                Stored data
 *    format                Format control string, see Format Specifications.
 *    arglist               pointer to list of arguments
 *
 * <OUTPUT PARAMETERS>
 *    arglist               the converted value stored in user assigned address
 *
 * <RETURN VALUE>
 *    Each of these functions returns the number of fields successfully converted
 *    and assigned; the return value does not include fields that were read but
 *    not assigned. A return value of 0 indicates that no fields were assigned.
 *    return -1 if an error occurs.
 *******************************************************************************
 */
int vswscanf_s(const wchar_t *buffer, const wchar_t *format, va_list arglist)
{
    SecFileStream fStr = SECUREC_INIT_SEC_FILE_STREAM;
    int retVal;                 /* If initialization causes  e838 */
    size_t count;               /* If initialization causes  e838 */

    /* validation section */
    if (buffer == NULL || format == NULL) {
        SECUREC_ERROR_INVALID_PARAMTER("vswscanf_s");
        return SECUREC_SCANF_EINVAL;
    }
    count = SecWcslen(buffer);
    if (count == 0 || count > SECUREC_WCHAR_STRING_MAX_LEN) {
        SecClearDestBufW(buffer, format, arglist);
        SECUREC_ERROR_INVALID_PARAMTER("vswscanf_s");
        return SECUREC_SCANF_EINVAL;
    }

    fStr.flag = SECUREC_MEM_STR_FLAG;
    fStr.cur = (const char *)buffer;
    fStr.count = (int)count *((int)sizeof(wchar_t));

    retVal = SecInputSW(&fStr, format, arglist);
    if (retVal < 0) {
        SECUREC_ERROR_INVALID_PARAMTER("vswscanf_s");
        return SECUREC_SCANF_EINVAL;
    }
    return retVal;
}