/*
 * Version reporting -- TODO.md section 2.2.16.
 *
 * There are two versions in play and the whole point of this API is that they
 * are allowed to differ:
 *
 *   the AKSL_VERSION_* macros   what the caller was COMPILED against, baked
 *                               into the caller's object file from whatever
 *                               akstdlib_version.h was on its include path
 *   aksl_version() and friends  what is actually LOADED, baked into
 *                               libakstdlib.so when the library was built
 *
 * In this test they necessarily agree, because the test binary and the library
 * are built from one tree in one configure. So the assertions below split into
 * two kinds: the ones that check the two sides agree (which would catch a build
 * that compiled the library and its tests against different generated headers),
 * and the ones that drive aksl_version_check() with deliberately wrong numbers
 * to prove it actually refuses a mismatch rather than always returning success.
 * The second kind is what makes the first kind worth anything.
 */

#include "aksl_capture.h"

static int test_version_string_matches_its_components(void)
{
    char expected[64];

    snprintf(expected, sizeof(expected), "%d.%d.%d",
	     AKSL_VERSION_MAJOR, AKSL_VERSION_MINOR, AKSL_VERSION_PATCH);
    AKSL_CHECK(strcmp(AKSL_VERSION_STRING, expected) == 0);
    return 0;
}

/*
 * AKSL_VERSION_NUMBER must be ordinary decimal arithmetic. Written out as a
 * literal it would be tempting to spell 0.1.0 as 000100, which C reads as
 * octal 64 -- so this compares the compile-time macro against the same figure
 * computed at runtime from the loaded library's own components. A literal that
 * went octal fails here; the current computed form cannot.
 */
static int test_version_number_is_decimal_and_ordered(void)
{
    int major = -1;
    int minor = -1;
    int patch = -1;

    AKSL_CHECK_OK(aksl_version(&major, &minor, &patch));
    AKSL_CHECK(AKSL_VERSION_NUMBER == (major * 10000) + (minor * 100) + patch);

    /* Usable in the preprocessor, which is the reason it exists at all. */
#if AKSL_VERSION_NUMBER < 0
    AKSL_CHECK(0 && "AKSL_VERSION_NUMBER is negative");
#endif
    AKSL_CHECK(AKSL_VERSION_NUMBER >= 0);
    return 0;
}

/* Header and shared library came out of the same configure. */
static int test_loaded_version_matches_the_header(void)
{
    int major = -1;
    int minor = -1;
    int patch = -1;

    AKSL_CHECK_OK(aksl_version(&major, &minor, &patch));
    AKSL_CHECK(major == AKSL_VERSION_MAJOR);
    AKSL_CHECK(minor == AKSL_VERSION_MINOR);
    AKSL_CHECK(patch == AKSL_VERSION_PATCH);

    AKSL_CHECK(strcmp(aksl_version_string(), AKSL_VERSION_STRING) == 0);
    AKSL_CHECK(strcmp(aksl_version_soname(), AKSL_VERSION_SONAME) == 0);
    return 0;
}

/*
 * The soname is the ABI-break granularity, and it mirrors the SOVERSION
 * expression in CMakeLists.txt: MAJOR.MINOR while major is 0, MAJOR alone after
 * that. If one of the two ever changes without the other, this fails.
 */
static int test_soname_matches_the_documented_rule(void)
{
    char expected[64];

#if AKSL_VERSION_MAJOR == 0
    snprintf(expected, sizeof(expected), "%d.%d",
	     AKSL_VERSION_MAJOR, AKSL_VERSION_MINOR);
#else
    snprintf(expected, sizeof(expected), "%d", AKSL_VERSION_MAJOR);
#endif
    AKSL_CHECK(strcmp(aksl_version_soname(), expected) == 0);
    return 0;
}

static int test_version_check_accepts_a_matching_build(void)
{
    AKSL_CHECK_OK(AKSL_VERSION_CHECK());
    return 0;
}

/*
 * The refusals. Without these the success above proves nothing -- a
 * aksl_version_check() that returned NULL unconditionally would pass it.
 */
static int test_version_check_refuses_a_mismatch(void)
{
    AKSL_CHECK_STATUS(aksl_version_check(AKSL_VERSION_MAJOR + 1,
					 AKSL_VERSION_MINOR,
					 AKSL_VERSION_PATCH),
		      AKERR_VALUE);
    AKSL_CHECK_STATUS(aksl_version_check(AKSL_VERSION_MAJOR,
					 AKSL_VERSION_MINOR + 1,
					 AKSL_VERSION_PATCH),
		      AKERR_VALUE);
    return 0;
}

/*
 * Patch is deliberately not part of the comparison: a patch bump is an ABI
 * promise, so a caller built against 0.1.0 must keep working against 0.1.7.
 */
static int test_version_check_ignores_the_patch_level(void)
{
    AKSL_CHECK_OK(aksl_version_check(AKSL_VERSION_MAJOR,
				     AKSL_VERSION_MINOR,
				     AKSL_VERSION_PATCH + 9));
    return 0;
}

/* The error has to say which two versions disagree, or it is not actionable. */
static int test_mismatch_message_names_both_versions(void)
{
    char compiled[64];

    snprintf(compiled, sizeof(compiled), "%d.%d.%d",
	     AKSL_VERSION_MAJOR + 1, AKSL_VERSION_MINOR, AKSL_VERSION_PATCH);

    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_version_check(AKSL_VERSION_MAJOR + 1,
						      AKSL_VERSION_MINOR,
						      AKSL_VERSION_PATCH),
				   AKERR_VALUE, compiled);
    AKSL_CHECK_STATUS_MSG_CONTAINS(aksl_version_check(AKSL_VERSION_MAJOR + 1,
						      AKSL_VERSION_MINOR,
						      AKSL_VERSION_PATCH),
				   AKERR_VALUE, AKSL_VERSION_STRING);
    return 0;
}

static int test_rejects_null_arguments(void)
{
    int major = 0;
    int minor = 0;
    int patch = 0;

    AKSL_CHECK_STATUS(aksl_version(NULL, &minor, &patch), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_version(&major, NULL, &patch), AKERR_NULLPOINTER);
    AKSL_CHECK_STATUS(aksl_version(&major, &minor, NULL), AKERR_NULLPOINTER);
    return 0;
}

int main(void)
{
    int failures = 0;

    akerr_init();

    AKSL_RUN(failures, test_version_string_matches_its_components);
    AKSL_RUN(failures, test_version_number_is_decimal_and_ordered);
    AKSL_RUN(failures, test_loaded_version_matches_the_header);
    AKSL_RUN(failures, test_soname_matches_the_documented_rule);
    AKSL_RUN(failures, test_version_check_accepts_a_matching_build);
    AKSL_RUN(failures, test_version_check_refuses_a_mismatch);
    AKSL_RUN(failures, test_version_check_ignores_the_patch_level);
    AKSL_RUN(failures, test_mismatch_message_names_both_versions);
    AKSL_RUN(failures, test_rejects_null_arguments);

    AKSL_REPORT(failures);
}