#include "akerror.h"
#include "err_capture.h"
#include <string.h>

/*
 * __akerr_copy_string() is the only place in the library that writes through a
 * caller-supplied pointer for a caller-supplied length, so it validates every
 * argument and raises rather than returning quietly. Both in-library callers
 * check their arguments before calling it, so this test is what drives those
 * guards -- without it they are unreachable code that no build ever exercises.
 */

int main(void)
{
    char buf[8];

    akerr_capture_install();
    akerr_init();

    /* The happy path: bounded, and always terminated. */
    memset(buf, 'x', sizeof(buf));
    AKERR_CHECK_SUCCEEDS(__akerr_copy_string(buf, (int)sizeof(buf), "abc"));
    AKERR_CHECK(strcmp(buf, "abc") == 0);

    /* A source longer than the buffer is truncated, never overrun. */
    memset(buf, 'x', sizeof(buf));
    AKERR_CHECK_SUCCEEDS(__akerr_copy_string(buf, (int)sizeof(buf), "abcdefghijkl"));
    AKERR_CHECK(strlen(buf) == sizeof(buf) - 1);
    AKERR_CHECK(buf[sizeof(buf) - 1] == '\0');
    AKERR_CHECK(strcmp(buf, "abcdefg") == 0);

    /* A capacity of exactly one holds nothing but the terminator. */
    memset(buf, 'x', sizeof(buf));
    AKERR_CHECK_SUCCEEDS(__akerr_copy_string(buf, 1, "abc"));
    AKERR_CHECK(buf[0] == '\0');
    AKERR_CHECK(buf[1] == 'x');   /* and wrote nothing past its capacity */

    /* NULL pointers raise instead of faulting, and the message says which. */
    AKERR_CHECK_RAISES(__akerr_copy_string(NULL, (int)sizeof(buf), "abc"),
		       AKERR_NULLPOINTER);
    AKERR_CHECK_MESSAGE_CONTAINS("destination");
    AKERR_CHECK_RAISES(__akerr_copy_string(buf, (int)sizeof(buf), NULL),
		       AKERR_NULLPOINTER);
    AKERR_CHECK_MESSAGE_CONTAINS("source");

    /* A capacity with no room for a terminator is a value error, not a write. */
    memset(buf, 'x', sizeof(buf));
    AKERR_CHECK_RAISES(__akerr_copy_string(buf, 0, "abc"), AKERR_VALUE);
    AKERR_CHECK_MESSAGE_CONTAINS("capacity of 0");
    AKERR_CHECK_RAISES(__akerr_copy_string(buf, -1, "abc"), AKERR_VALUE);
    AKERR_CHECK(buf[0] == 'x');   /* nothing was written */

    /* Each refusal handed its context back to the pool. */
    AKERR_CHECK(akerr_slots_in_use() == 0);

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