/*
 * vlibc — pwd.h/grp.h test (todo 37).
 *
 * Exercises the password and group databases end to end without assuming
 * anything about their CONTENTS: every lookup is asserted either to
 * return a sane record (string fields non-NULL, ids echo the key) or
 * NULL, and every stream walk is asserted only to terminate cleanly. The
 * one environment precondition is that /etc/passwd and /etc/group EXIST
 * and are readable; when either is absent the whole test skips (rc 0),
 * detected through a raw SYS_faccessat so no vlibc errno slot is touched
 * on the skip path.
 *
 * Scenarios (all content-independent):
 *
 *   1. current-uid: getpwuid(getuid()) is NULL or a record whose pw_uid
 *      echoes the key and whose pw_name is set; when a record comes back,
 *      getpwnam(pw_name) finds it again (name round-trip).
 *   2. current-gid: the same pair against the group database.
 *   3. stream walk: setpwent/getpwent/endpwent; two consecutive full
 *      walks return the same count (the stream really rewinds), every
 *      record is sane, and the walk terminates.
 *   4. group members: every parsed record has a non-NULL gr_mem array
 *      (the empty list is a single NULL entry), and member arrays
 *      terminate.
 *   5. _r forms: getpwuid_r/getgrgid_r into a 4096-byte buffer return 0
 *      and either *result == NULL (key absent) or a filled struct echoing
 *      the key; getpwent_r/getgrent_r likewise fill one record.
 *   6. NULL keys: getpwnam(NULL)/getgrnam(NULL) return NULL (defensive
 *      contract, no crash).
 *   7. -f mode: impossible keys (uid/gid 2147483647, a name no real
 *      database carries) come back NULL without crashing, then the test
 *      leaves via a raw SYS_exit_group (house pattern: after a vlibc
 *      errno-capable call the host TCB may be dirty).
 *   8. fgetgrent (level 2 only): parse one record from an explicitly
 *      fopen'd stream.
 *
 * Host headers are never included; <pwd.h>/<grp.h>/<unistd.h> are
 * vlibc's own (-Iinclude shadows the system copies). getuid/getgid come
 * from src/process/uid.c.
 */

#include <grp.h>
#include <pwd.h>
#include <unistd.h>

#include <vlibc/internal/test.h>

/* Local kernel-ABI constants for the skip probe (no public header pulled). */
#define PG_AT_FDCWD (-100)
#define PG_R_OK 4

/* Both databases readable (the only environment assumption). */
static int
pg_db_present(void)
{
    return __syscall4(SYS_faccessat, PG_AT_FDCWD, (long)"/etc/passwd", PG_R_OK, 0) == 0 &&
           __syscall4(SYS_faccessat, PG_AT_FDCWD, (long)"/etc/group", PG_R_OK, 0) == 0;
}

static int
test_current_uid(void)
{
    uid_t uid = getuid();
    struct passwd *p = getpwuid(uid);

    if (p == NULL)
    {
        return 0; /* key absent from the database: acceptable */
    }
    TEST_ASSERT_TRUE(p->pw_name != NULL);
    TEST_ASSERT_EQ((unsigned long)p->pw_uid, (unsigned long)uid);
    if (p->pw_name != NULL)
    {
        struct passwd *q = getpwnam(p->pw_name);

        TEST_ASSERT_TRUE(q != NULL);
        if (q != NULL)
        {
            TEST_ASSERT_EQ((unsigned long)q->pw_uid, (unsigned long)uid);
        }
    }
    return 0;
}

static int
test_current_gid(void)
{
    gid_t gid = getgid();
    struct group *g = getgrgid(gid);

    if (g == NULL)
    {
        return 0; /* key absent from the database: acceptable */
    }
    TEST_ASSERT_TRUE(g->gr_name != NULL);
    TEST_ASSERT_EQ((unsigned long)g->gr_gid, (unsigned long)gid);
    if (g->gr_name != NULL)
    {
        struct group *h = getgrnam(g->gr_name);

        TEST_ASSERT_TRUE(h != NULL);
        if (h != NULL)
        {
            TEST_ASSERT_EQ((unsigned long)h->gr_gid, (unsigned long)gid);
        }
    }
    return 0;
}

/* Count the records of one full pwd walk, sanity-checking each. */
static unsigned long
pg_pwd_walk_count(void)
{
    struct passwd *p;
    unsigned long n = 0;

    setpwent();
    while ((p = getpwent()) != NULL)
    {
        TEST_ASSERT_TRUE(p->pw_name != NULL);
        if (++n > 100000UL)
        {
            break; /* runaway guard: the walk must terminate */
        }
    }
    endpwent();
    return n;
}

static int
test_pwd_stream(void)
{
    unsigned long first = pg_pwd_walk_count();
    unsigned long second = pg_pwd_walk_count();

    /* The walk terminates and setpwent really rewinds (0 == 0 for an
     * empty database is still a valid equality). */
    TEST_ASSERT_TRUE(first < 100000UL);
    TEST_ASSERT_EQ(first, second);

    /* After endpwent a fresh getpwent reopens from the start: the result
     * is the first record, or NULL only when the database is empty. */
    if (first != 0)
    {
        struct passwd *p = getpwent();

        TEST_ASSERT_TRUE(p != NULL);
        endpwent();
    }
    return 0;
}

/* Every parsed group has a terminating gr_mem array; empty lists appear
 * as a single NULL entry, so gr_mem itself is never NULL. */
static int
test_group_members(void)
{
    struct group *g;
    unsigned long n = 0;

    setgrent();
    while ((g = getgrent()) != NULL)
    {
        char **m;
        unsigned long members = 0;

        TEST_ASSERT_TRUE(g->gr_name != NULL);
        TEST_ASSERT_TRUE(g->gr_mem != NULL);
        for (m = g->gr_mem; m != NULL && *m != NULL; m++)
        {
            TEST_ASSERT_TRUE(**m != '\0');
            if (++members > 100000UL)
            {
                break; /* runaway guard: member arrays must terminate */
            }
        }
        TEST_ASSERT_TRUE(members < 100000UL);
        if (++n > 100000UL)
        {
            break;
        }
    }
    endgrent();
    TEST_ASSERT_TRUE(n < 100000UL);
    return 0;
}

static int
test_pwd_r(void)
{
    struct passwd pw;
    struct passwd *res = NULL;
    char buf[4096];
    int rc = getpwuid_r(getuid(), &pw, buf, sizeof buf, &res);

    TEST_ASSERT_EQ(rc, 0);
    TEST_ASSERT_TRUE(res == NULL || res == &pw);
    if (res == &pw)
    {
        TEST_ASSERT_EQ((unsigned long)pw.pw_uid, (unsigned long)getuid());
        TEST_ASSERT_TRUE(pw.pw_name != NULL);
    }
    return 0;
}

static int
test_grp_r(void)
{
    struct group gr;
    struct group *res = NULL;
    char buf[4096];
    int rc = getgrgid_r(getgid(), &gr, buf, sizeof buf, &res);

    TEST_ASSERT_EQ(rc, 0);
    TEST_ASSERT_TRUE(res == NULL || res == &gr);
    if (res == &gr)
    {
        TEST_ASSERT_EQ((unsigned long)gr.gr_gid, (unsigned long)getgid());
        TEST_ASSERT_TRUE(gr.gr_name != NULL);
        TEST_ASSERT_TRUE(gr.gr_mem != NULL);
    }
    return 0;
}

static int
test_null_keys(void)
{
    TEST_ASSERT_TRUE(getpwnam(NULL) == NULL);
    TEST_ASSERT_TRUE(getgrnam(NULL) == NULL);
    return 0;
}

#if VLIBC_LEVEL_GE(2)

static int
test_fgetgrent(void)
{
    FILE *f = fopen("/etc/group", "r");
    struct group *g;

    if (f == NULL)
    {
        return 0; /* opened by the caller, closed by the caller */
    }
    g = fgetgrent(f);
    if (g != NULL)
    {
        TEST_ASSERT_TRUE(g->gr_name != NULL);
        TEST_ASSERT_TRUE(g->gr_mem != NULL);
    }
    (void)fclose(f);
    return 0;
}

#endif /* VLIBC_LEVEL_GE(2) */

static const struct vlibc_test tests[] = {
    {"current-uid", test_current_uid},
    {"current-gid", test_current_gid},
    {"pwd-stream", test_pwd_stream},
    {"group-members", test_group_members},
    {"pwd-r", test_pwd_r},
    {"grp-r", test_grp_r},
    {"null-keys", test_null_keys},
#if VLIBC_LEVEL_GE(2)
    {"fgetgrent", test_fgetgrent},
#endif
};

/*
 * Own main (not TEST_MAIN): supports the -f failure mode. Everything else
 * follows the TEST_MAIN contract — same output shape, 0 on all-pass.
 */
int
main(int argc, char **argv)
{
    const size_t count = sizeof tests / sizeof tests[0];
    size_t passed = 0;
    size_t i;

    if (argc > 1 && argv[1][0] == '-' && argv[1][1] == 'f' && argv[1][2] == '\0')
    {
        /* Impossible keys must come back NULL without crashing. */
        int before = vlibc_test_failures;
        uid_t uid = (uid_t)2147483647UL;
        gid_t gid = (gid_t)2147483647UL;

        vlibc_test_say(1, "RUN missing-lookups: ");
        TEST_ASSERT_TRUE(getpwuid(uid) == NULL);
        TEST_ASSERT_TRUE(getgrgid(gid) == NULL);
        TEST_ASSERT_TRUE(getpwnam("vlibc-no-such-user-xyz") == NULL);
        TEST_ASSERT_TRUE(getgrnam("vlibc-no-such-group-xyz") == NULL);
        if (vlibc_test_failures == before)
        {
            vlibc_test_say(1, "PASS\n");
            vlibc_test_say(1, "SUMMARY: 1/1 passed, 0 assertion failure(s)\n");
        }
        else
        {
            vlibc_test_say(1, "FAIL\n");
        }

        /* Raw exit: the NULL-return paths may have written the library's
         * errno slot, which collides with the host TCB (house pattern). */
        __syscall1(SYS_exit_group, vlibc_test_failures == before ? 0 : 1);
        /* not reached */
    }

    if (!pg_db_present())
    {
        vlibc_test_say(1, "SKIP: /etc/passwd or /etc/group absent, nothing to look up\n");
        __syscall1(SYS_exit_group, 0);
        /* not reached */
    }

    for (i = 0; i < count; i++)
    {
        int before = vlibc_test_failures;

        vlibc_test_say(1, "RUN ");
        vlibc_test_say(1, tests[i].name);
        vlibc_test_say(1, ": ");
        if (tests[i].run() == 0 && vlibc_test_failures == before)
        {
            vlibc_test_say(1, "PASS\n");
            passed++;
        }
        else
        {
            vlibc_test_say(1, "FAIL\n");
        }
    }

    vlibc_test_say(1, "SUMMARY: ");
    vlibc_test_say_dec(1, (unsigned long)passed);
    vlibc_test_say(1, "/");
    vlibc_test_say_dec(1, (unsigned long)count);
    vlibc_test_say(1, " passed, ");
    vlibc_test_say_dec(1, (unsigned long)vlibc_test_failures);
    vlibc_test_say(1, " assertion failure(s)\n");

    return passed == count ? 0 : 1;
}