#include "akerror.h"
#include "err_capture.h"

/*
 * The error pool is a fixed array of AKERR_MAX_ARRAY_ERROR slots. When every
 * slot is checked out, akerr_next_error() must return NULL rather than run off
 * the end of the array; and it must always hand back the lowest free slot.
 * Mutation testing showed both the terminating "return NULL" and the scan
 * bounds could be broken without any test noticing.
 */

int main(void)
{
    akerr_init();

    akerr_ErrorContext *slots[AKERR_MAX_ARRAY_ERROR];

    /* Check out every slot. Each arrives holding its own reference, so the
     * next request cannot be handed the same one. */
    for ( int i = 0; i < AKERR_MAX_ARRAY_ERROR; i++ ) {
        slots[i] = akerr_next_error();
        AKERR_CHECK(slots[i] != NULL);
        AKERR_CHECK(slots[i]->refcount == 1);
    }

    /* Pool is fully exhausted: the next request must fail cleanly. */
    AKERR_CHECK(akerr_next_error() == NULL);

    /* Free exactly the first slot; the scan must find and return it. */
    slots[0]->refcount = 0;
    AKERR_CHECK(akerr_next_error() == slots[0]);

    /* Tidy up. */
    for ( int i = 0; i < AKERR_MAX_ARRAY_ERROR; i++ ) {
        slots[i]->refcount = 0;
    }

    fprintf(stderr, "err_pool_exhaust ok\n");
    return 0;
}