// User-mode smoke test for POSIX process/thread runtime state and public headers.

#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>
#include <dlfcn.h>
#include <pwd.h>
#include <grp.h>
#include <ntlite/syscall.h>

static volatile int gWorkerErrno;
static volatile uintptr_t gWorkerErrnoAddress;
static volatile int gWorkerDlErrorOk;
static volatile pid_t gWorkerPid;

// Writes one NUL-terminated string to stdout.
static void print(const char* text) {
    (void)write(1, text, strlen(text));
}

// Terminates the smoke test with one diagnostic.
static void fail(const char* message) {
    print("posix_runtime_smoke: ");
    print(message);
    print("\n");
    exit(1);
}

// Mutates errno and dlerror in a second POSIX thread.
static void* worker(void* argument) {
    (void)argument;

    if (errno != 0)
        return (void*)1;

    gWorkerErrnoAddress = (uintptr_t)__ntl_posix_errno_location();
    gWorkerPid = getpid();
    errno = 222;

    if (dlsym((void*)0, "worker_missing_symbol") != (void*)0)
        return (void*)2;
    char* error = dlerror();
    if (!error || !error[0] || dlerror() != (char*)0)
        return (void*)3;

    gWorkerErrno = errno;
    gWorkerDlErrorOk = 1;
    return (void*)0x1234;
}

// Runs the POSIX runtime foundation smoke test.
int main(void) {
    print("posix_runtime_smoke: start\n");

    if (_POSIX_VERSION != 199009L)
        fail("wrong POSIX profile version");

    uintptr_t mainErrnoAddress = (uintptr_t)__ntl_posix_errno_location();
    if (!mainErrnoAddress)
        fail("main errno address is null");

    pid_t stablePid = getpid();
    if (stablePid <= 0)
        fail("stable POSIX pid was invalid");
    if ((uint32_t)stablePid == SysGetCurrentPid())
        fail("getpid leaked native pid");

    errno = 77;
    if (dlsym((void*)0, "main_missing_symbol") != (void*)0)
        fail("main dlsym unexpectedly succeeded");
    if (!dlerror())
        fail("main dlerror was not set");

    // Re-arm one main-thread loader error so the worker can prove isolation.
    if (dlsym((void*)0, "main_missing_symbol_2") != (void*)0)
        fail("second main dlsym unexpectedly succeeded");
    errno = 77;

    pthread_t thread;
    int createStatus = pthread_create(&thread, (const pthread_attr_t*)0, worker, (void*)0);
    if (createStatus != 0)
        fail("pthread_create failed");

    void* result = (void*)0;
    int joinStatus = pthread_join(thread, &result);
    if (joinStatus != 0)
        fail("pthread_join failed");
    if (result != (void*)0x1234)
        fail("worker returned wrong value");

    if (gWorkerErrnoAddress == 0 || gWorkerErrnoAddress == mainErrnoAddress)
        fail("errno storage was shared between threads");
    if (gWorkerPid != stablePid)
        fail("worker did not inherit logical POSIX process identity");
    if (gWorkerErrno != EINVAL || !gWorkerDlErrorOk)
        fail("worker thread-local state was wrong");
    if (errno != 77)
        fail("worker changed main errno");

    char* mainError = dlerror();
    if (!mainError || !mainError[0])
        fail("worker consumed main dlerror");
    if (dlerror() != (char*)0)
        fail("main dlerror did not clear");

    if (getuid() != 0 || geteuid() != 0 || getgid() != 0 || getegid() != 0)
        fail("initial synthetic credentials were wrong");
    if (getgroups(0, (gid_t*)0) != 0)
        fail("initial supplementary group set was wrong");
    char* login = getlogin();
    if (!login || strcmp(login, "root") != 0)
        fail("initial login identity was wrong");

    struct passwd* root = getpwnam("root");
    if (!root || root->pw_uid != 0 || root->pw_gid != 0 || strcmp(root->pw_name, "root") != 0)
        fail("root passwd lookup failed");
    struct passwd* user = getpwuid(1000);
    if (!user || user->pw_uid != 1000 || user->pw_gid != 1000 || strcmp(user->pw_name, "user") != 0)
        fail("user passwd lookup failed");
    struct group* users = getgrnam("users");
    if (!users || users->gr_gid != 1000 || strcmp(users->gr_name, "users") != 0 ||
        !users->gr_mem || users->gr_mem[0] != (char*)0)
        fail("group lookup failed");
    if (getgrgid(0) == (struct group*)0)
        fail("group id lookup failed");

    if (getpgrp() != stablePid)
        fail("initial process group was wrong");
    errno = 0;
    if (setsid() != (pid_t)-1 || errno != EPERM)
        fail("session leader unexpectedly created another session");
    errno = 0;
    if (setpgid(0, 0) != -1 || errno != EPERM)
        fail("session leader unexpectedly changed process group");

    char originalCwd[256];
    if (!getcwd(originalCwd, sizeof(originalCwd)))
        fail("getcwd before chdir failed");
    if (chdir("/") != 0)
        fail("chdir root failed");
    char rootCwd[16];
    if (!getcwd(rootCwd, sizeof(rootCwd)) || strcmp(rootCwd, "/") != 0)
        fail("chdir root did not update cwd");
    if (chdir(originalCwd) != 0)
        fail("cwd restore failed");

    if (setgid(1000) != 0 || getgid() != 1000 || getegid() != 1000)
        fail("root setgid failed");
    if (setuid(1000) != 0 || getuid() != 1000 || geteuid() != 1000)
        fail("root setuid failed");
    errno = 0;
    if (setgid(0) != -1 || errno != EPERM)
        fail("dropped uid retained setgid authority");
    errno = 0;
    if (setuid(0) != -1 || errno != EPERM)
        fail("dropped uid regained root");
    if (!getlogin() || strcmp(getlogin(), "root") != 0)
        fail("login identity changed with effective uid");

    print("posix_runtime_smoke: PASS\n");
    return 0;
}