/**
 * @file common.c
 * @author Michal Vasko <mvasko@cesnet.cz>
 * @brief common internal definitions for libyang
 *
 * Copyright (c) 2018 CESNET, z.s.p.o.
 *
 * This source code is licensed under BSD 3-Clause License (the "License").
 * You may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://opensource.org/licenses/BSD-3-Clause
 */
#define _XOPEN_SOURCE

#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <time.h>

#include "tree_schema.h"

void *
ly_realloc(void *ptr, size_t size)
{
    void *new_mem;

    new_mem = realloc(ptr, size);
    if (!new_mem) {
        free(ptr);
    }

    return new_mem;
}

int
lysp_check_date(struct ly_ctx *ctx, const char *date, int date_len)
{
    int i;
    struct tm tm, tm_;
    char *r;

    if (date_len != LY_REV_SIZE - 1) {
        goto error;
    }

    /* check format */
    for (i = 0; i < date_len; i++) {
        if (i == 4 || i == 7) {
            if (date[i] != '-') {
                goto error;
            }
        } else if (!isdigit(date[i])) {
            goto error;
        }
    }

    /* check content, e.g. 2018-02-31 */
    memset(&tm, 0, sizeof tm);
    r = strptime(date, "%Y-%m-%d", &tm);
    if (!r || r != &date[LY_REV_SIZE - 1]) {
        goto error;
    }
    memcpy(&tm_, &tm, sizeof tm);
    mktime(&tm_); /* mktime modifies tm_ if it refers invalid date */
    if (tm.tm_mday != tm_.tm_mday) { /* e.g 2018-02-29 -> 2018-03-01 */
        /* checking days is enough, since other errors
         * have been checked by strptime() */
        goto error;
    }

    return 0;

error:
    fprintf(stderr, "Invalid date format \"%.*s\".\n", date_len, date);
    return -1;
}