/*
* Copyright (c) 2017 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/

#ifndef DST_VECTOR_H_defined
#define DST_VECTOR_H_defined

/*
 * vector code modified from
 * https://github.com/nothings/stb/blob/master/stretchy_buffer.h
*/

/* This is mainly used code such as the assembler or compiler, which
 * need vector like data structures that are not garbage collected
 * and used only from C */

#define dst_v_free(v)         (((v) != NULL) ? (free(dst_v__raw(v)), 0) : 0)
#define dst_v_push(v, x)      (dst_v__maybegrow(v, 1), (v)[dst_v__cnt(v)++] = (x))
#define dst_v_pop(v)          (dst_v_count(v) ? dst_v__cnt(v)-- : 0)
#define dst_v_count(v)        (((v) != NULL) ? dst_v__cnt(v) : 0)
#define dst_v_add(v, n)       (dst_v__maybegrow(v, n), dst_v_cnt(v) += (n), &(v)[dst_v__cnt(v) - (n)])
#define dst_v_last(v)         ((v)[dst_v__cnt(v) - 1])
#define dst_v_empty(v)        (((v) != NULL) ? (dst_v__cnt(v) = 0) : 0)
#define dst_v_copy(v)         (dst_v_copymem((v), sizeof(*(v))))
#define dst_v_flatten(v)      (dst_v_flattenmem((v), sizeof(*(v))))

#define dst_v__raw(v) ((int32_t *)(v) - 2)
#define dst_v__cap(v) dst_v__raw(v)[0]
#define dst_v__cnt(v) dst_v__raw(v)[1]

#define dst_v__needgrow(v, n)  ((v) == NULL || dst_v__cnt(v) + (n) >= dst_v__cap(v))
#define dst_v__maybegrow(v, n) (dst_v__needgrow((v), (n)) ? dst_v__grow((v), (n)) : 0)
#define dst_v__grow(v, n)      ((v) = dst_v_grow((v), (n), sizeof(*(v))))


/* Vector code */

/* Grow the buffer dynamically. Used for push operations. */
#ifndef DST_V_NODEF_GROW
static void *dst_v_grow(void *v, int32_t increment, int32_t itemsize) {
    int32_t dbl_cur = (NULL != v) ? 2 * dst_v__cap(v) : 0;
    int32_t min_needed = dst_v_count(v) + increment;
    int32_t m = dbl_cur > min_needed ? dbl_cur : min_needed;
    int32_t *p = (int32_t *) realloc(v ? dst_v__raw(v) : 0, itemsize * m + sizeof(int32_t)*2);
    if (NULL != p) {
        if (!v) p[1] = 0;
        p[0] = m;
        return p + 2;
   } else {
       {
           DST_OUT_OF_MEMORY;
       }
       return (void *) (2 * sizeof(int32_t)); // try to force a NULL pointer exception later
   }
}
#endif

/* Clone a buffer. */
#ifdef DST_V_DEF_COPYMEM
static void *dst_v_copymem(void *v, int32_t itemsize) {
    int32_t *p;
    if (NULL == v) return NULL;
    p = malloc(2 * sizeof(int32_t) + itemsize * dst_v__cap(v));
    if (NULL != p) {
        memcpy(p, dst_v__raw(v), 2 * sizeof(int32_t) + itemsize * dst_v__cnt(v));
        return p + 2;
    } else {
       {
           DST_OUT_OF_MEMORY;
       }
       return (void *) (2 * sizeof(int32_t)); // try to force a NULL pointer exception later
    }
}
#endif

/* Convert a buffer to normal allocated memory (forget capacity) */
#ifdef DST_V_DEF_FLATTENMEM
static void *dst_v_flattenmem(void *v, int32_t itemsize) {
    int32_t *p;
    int32_t sizen;
    if (NULL == v) return NULL;
    sizen = itemsize * dst_v__cnt(v);
    p = malloc(sizen);
    if (NULL != p) {
        memcpy(p, v, sizen);
        return p;
    } else {
       {
           DST_OUT_OF_MEMORY;
       }
       return NULL;
    }
}
#endif

#endif