/* SPDX-License-Identifier: LicenseRef-Starship-1.0
 * Copyright (c) 2023-2026 Robert A. James
 */
/* test_sk_v4_slots.c -- kernel/src/v4/sk_v4_slots.c on the host (#178): a controller's drive slots
 * are allocated once and never replaced, so the pointers the identity code keeps into them (the
 * offered stick, the spare, Zuse's device) stay good. kmalloc_aligned is faked.
 */
#define _POSIX_C_SOURCE 200809L
#include "harness.h"
#include "starkernel/v4/sk_v4_slots.h"
#include <stdlib.h>
#include <string.h>

static unsigned allocs;
void *kmalloc_aligned(size_t size, size_t align) { void *p = 0; allocs++; return posix_memalign(&p, align, size) ? 0 : p; }

typedef struct { int attached; char name[16]; } drive;   /* a slot, as sk_v4_drive_t is to the identity code */

int main(void)
{
    void *slots = 0;
    uint32_t count = 0, n;
    drive *d, *held;

    n = sk_v4_slots_get(&slots, &count, 9u, sizeof(drive));
    d = (drive *)slots;
    CHECK(n == 9u && d && allocs == 1u && d[3].attached == 0, "first: 9 zeroed slots, one allocation (n %u)", n);
    d[3].attached = 1; strcpy(d[3].name, "Zuse");
    held = &d[3];                                       /* as g_zuse_dev, g_offered, g_spare hold one */

    n = sk_v4_slots_get(&slots, &count, 9u, sizeof(drive));
    CHECK(slots == (void *)d && n == 9u && allocs == 1u, "again, the same size: the same array, no allocation");

    n = sk_v4_slots_get(&slots, &count, 17u, sizeof(drive));
    CHECK(slots == (void *)d && allocs == 1u, "#178: asked for more: the same array, not replaced (allocations %u)", allocs);
    CHECK(n == 9u, "#178: and only the 9 slots it has may be used, not 17 (n %u)", n);
    CHECK(held->attached == 1 && strcmp(held->name, "Zuse") == 0 && held == &((drive *)slots)[3],
          "#178: a pointer held into a slot is still the slot, with the drive in it");

    {
        void *none = 0; uint32_t c = 0;
        unsigned before = allocs;
        CHECK(sk_v4_slots_get(&none, &c, 0u, sizeof(drive)) == 0u && none == 0 && allocs == before,
              "0 slots wanted: none to use, nothing allocated");
    }
    return DONE();
}