// Advisory file-lock smoke test.
// Verifies process-owned byte-range conflicts, timeout behavior, and exit cleanup.

#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <ntlite/syscall.h>

#define LOCK_OFFSET 0u
#define LOCK_LENGTH 128u
#define NONOVERLAP_OFFSET 512u
#define CHILD_PREFIX_MAX 32u
#define CHILD_PATH_MAX 256u

// Prints one NUL-terminated string to the kernel console.
static void print(const char* s) {
    SYS_WRITE_CONSOLE_REQUEST req = { SysSvFromCstr(s) };
    SysWriteConsole(&req);
}

// Prints one unsigned integer to the kernel console.
static void print_u64(uint64_t v) {
    char buf[32];
    int i = 0;
    if (v == 0) {
        print("0");
        return;
    }
    while (v && i < (int)sizeof(buf)) {
        buf[i++] = (char)('0' + (v % 10));
        v /= 10;
    }
    while (i--) {
        char c = buf[i];
        SYS_WRITE_CONSOLE_REQUEST req = { SysSvFromParts(&c, 1) };
        SysWriteConsole(&req);
    }
}

// Terminates the current test process.
static void exit_now(int32_t code) {
    while (true) SysExitProcess(code);
}

// Fails the test with one status value.
static void fail_status(const char* what, uint32_t status) {
    print("file_lock_smoke: ");
    print(what);
    print(" status=");
    print_u64(status);
    print("\n");
    exit_now(1);
}

// Fails the test with one plain message.
static void fail(const char* what) {
    print("file_lock_smoke: ");
    print(what);
    print("\n");
    exit_now(1);
}

// Deletes one path if it already exists.
static void delete_path(const char* path) {
    SYS_PATH_REQUEST req = { SysSvFromCstr(path) };
    (void)SysDeleteFile(&req);
}

// Opens one path with lock rights.
static uint32_t open_existing_lockable(const char* path, uint32_t* fileOut) {
    uint32_t h = 0;
    SYS_OPEN_FILE_REQUEST req = SysMakeOpenFileRequest(SysSvFromCstr(path),
                                                       SYS_FILE_ACCESS_QUERY | SYS_FILE_ACCESS_LOCK,
                                                       SYS_FILE_OPEN_EXISTING,
                                                       SYS_FILE_FLAG_NONE,
                                                       &h);
    uint32_t s = SysOpenFile(&req);
    if (s == NTLSTATUS_SUCCESS)
        *fileOut = h;
    return s;
}

// Creates a temporary file on the first writable path that works.
static uint32_t create_temp_file(uint32_t* fileOut, const char** pathOut) {
    static const char* paths[] = {
        "file_lock_smoke.tmp",
        "/file_lock_smoke.tmp",
        "1:/file_lock_smoke.tmp",
        "0:/file_lock_smoke.tmp",
    };

    for (size_t i = 0; i < sizeof(paths) / sizeof(paths[0]); i++) {
        uint32_t h = 0;
        delete_path(paths[i]);
        SYS_OPEN_FILE_REQUEST req = SysMakeOpenFileRequest(SysSvFromCstr(paths[i]),
                                                           SYS_FILE_ACCESS_READ | SYS_FILE_ACCESS_WRITE | SYS_FILE_ACCESS_QUERY | SYS_FILE_ACCESS_LOCK,
                                                           SYS_FILE_CREATE_NEW,
                                                           SYS_FILE_FLAG_NONE,
                                                           &h);
        uint32_t s = SysOpenFile(&req);
        if (s == NTLSTATUS_SUCCESS) {
            *fileOut = h;
            *pathOut = paths[i];
            return NTLSTATUS_SUCCESS;
        }
    }
    return NTLSTATUS_NOT_FOUND;
}

// Locks a range through the public request ABI.
static uint32_t lock_range(uint32_t file, uint32_t mode, uint64_t offset, uint64_t length, uint64_t timeoutMs) {
    SYS_LOCK_FILE_REQUEST req = {
        sizeof(req),
        file,
        mode,
        SYS_FILE_LOCK_FLAG_NONE,
        offset,
        length,
        timeoutMs,
    };
    return SysLockFile(&req);
}

// Unlocks a range through the public request ABI.
static uint32_t unlock_range(uint32_t file, uint64_t offset, uint64_t length) {
    SYS_UNLOCK_FILE_REQUEST req = {
        sizeof(req),
        file,
        SYS_FILE_LOCK_FLAG_NONE,
        offset,
        length,
    };
    return SysUnlockFile(&req);
}

// Splits the child command line into mode and path.
static int parse_child_command(SYS_STRING_VIEW view, char* mode, size_t modeCap, char* path, size_t pathCap) {
    if (!view.Data || view.Length == 0)
        return 0;
    size_t sep = 0;
    while (sep < view.Length && view.Data[sep] != ':')
        sep++;
    if (sep == view.Length || sep + 1 >= view.Length)
        return 0;
    if (sep + 1 > modeCap || view.Length - sep > pathCap)
        return 0;
    memcpy(mode, view.Data, sep);
    mode[sep] = '\0';
    memcpy(path, view.Data + sep + 1, view.Length - sep - 1);
    path[view.Length - sep - 1] = '\0';
    return 1;
}

// Returns whether two NUL-terminated strings are equal.
static int str_eq(const char* a, const char* b) {
    return strcmp(a, b) == 0;
}

// Returns whether one mode name belongs to the child command protocol.
static int is_child_mode(const char* mode) {
    return str_eq(mode, "excl-blocked") ||
           str_eq(mode, "excl-timeout") ||
           str_eq(mode, "excl-wait") ||
           str_eq(mode, "shared-ok") ||
           str_eq(mode, "excl-nonoverlap") ||
           str_eq(mode, "hold-exit");
}

// Child process entry for cross-process lock checks.
static void run_child(SYS_STRING_VIEW commandLine) {
    char mode[CHILD_PREFIX_MAX];
    char path[CHILD_PATH_MAX];
    if (!parse_child_command(commandLine, mode, sizeof(mode), path, sizeof(path)))
        exit_now(2);

    uint32_t file = 0;
    uint32_t s = open_existing_lockable(path, &file);
    if (s != NTLSTATUS_SUCCESS)
        exit_now(3);

    if (str_eq(mode, "excl-blocked")) {
        s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, 0);
        SysCloseHandle(file);
        exit_now(s == NTLSTATUS_WOULD_BLOCK ? 0 : 4);
    }

    if (str_eq(mode, "excl-timeout")) {
        s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, 20);
        SysCloseHandle(file);
        exit_now(s == NTLSTATUS_TIMEOUT ? 0 : 5);
    }

    if (str_eq(mode, "excl-wait")) {
        s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, SYS_WAIT_TIMEOUT_INFINITE);
        if (s == NTLSTATUS_SUCCESS)
            (void)unlock_range(file, LOCK_OFFSET, LOCK_LENGTH);
        SysCloseHandle(file);
        exit_now(s == NTLSTATUS_SUCCESS ? 0 : 6);
    }

    if (str_eq(mode, "shared-ok")) {
        s = lock_range(file, SYS_FILE_LOCK_SHARED, LOCK_OFFSET, LOCK_LENGTH, 0);
        if (s == NTLSTATUS_SUCCESS)
            (void)unlock_range(file, LOCK_OFFSET, LOCK_LENGTH);
        SysCloseHandle(file);
        exit_now(s == NTLSTATUS_SUCCESS ? 0 : 7);
    }

    if (str_eq(mode, "excl-nonoverlap")) {
        s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, NONOVERLAP_OFFSET, LOCK_LENGTH, 0);
        if (s == NTLSTATUS_SUCCESS)
            (void)unlock_range(file, NONOVERLAP_OFFSET, LOCK_LENGTH);
        SysCloseHandle(file);
        exit_now(s == NTLSTATUS_SUCCESS ? 0 : 8);
    }

    if (str_eq(mode, "hold-exit")) {
        s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, 0);
        SysCloseHandle(file);
        exit_now(s == NTLSTATUS_SUCCESS ? 0 : 9);
    }

    SysCloseHandle(file);
    exit_now(10);
}

// Builds a child command line of the form mode:path.
static void build_child_command(char* out, size_t outCap, const char* mode, const char* path) {
    size_t modeLen = strlen(mode);
    size_t pathLen = strlen(path);
    if (modeLen + 1 + pathLen + 1 > outCap)
        fail("child command too long");
    memcpy(out, mode, modeLen);
    out[modeLen] = ':';
    memcpy(out + modeLen + 1, path, pathLen + 1);
}

// Runs this image as a child and requires a zero exit code.
static void run_child_expect_success(const char* mode, const char* path) {
    SYS_PEB* peb = SysGetPeb();
    if (!peb || !peb->ImagePath.Data || peb->ImagePath.Length == 0)
        fail("missing image path");

    char command[CHILD_PREFIX_MAX + CHILD_PATH_MAX];
    build_child_command(command, sizeof(command), mode, path);

    uint32_t child = 0;
    SYS_CREATE_PROCESS_REQUEST req = {
        peb->ImagePath,
        SysSvFromCstr(command),
        &child,
    };
    uint32_t s = SysCreateProcess(&req);
    if (s != NTLSTATUS_SUCCESS) fail_status("create child", s);

    s = SysWait(child, SYS_WAIT_FLAG_NONE);
    if (s != NTLSTATUS_SUCCESS) fail_status("wait child", s);

    int32_t exitCode = 0;
    s = SysGetProcessExitCode(child, &exitCode);
    if (s != NTLSTATUS_SUCCESS) fail_status("query child", s);
    SysCloseHandle(child);
    if (exitCode != 0) {
        print("file_lock_smoke: child ");
        print(mode);
        print(" exited ");
        print_u64((uint32_t)exitCode);
        print("\n");
        exit_now(1);
    }
}

// Verifies validation paths that should not depend on filesystem state.
static void test_validation(uint32_t file) {
    SYS_LOCK_FILE_REQUEST lockReq = {
        0,
        file,
        SYS_FILE_LOCK_EXCLUSIVE,
        SYS_FILE_LOCK_FLAG_NONE,
        LOCK_OFFSET,
        LOCK_LENGTH,
        0,
    };
    uint32_t s = SysLockFile(&lockReq);
    if (s != NTLSTATUS_INVALID_PARAMETER) fail_status("bad lock size", s);

    lockReq.Size = sizeof(lockReq);
    lockReq.Length = 0;
    s = SysLockFile(&lockReq);
    if (s != NTLSTATUS_INVALID_PARAMETER) fail_status("zero lock length", s);

    SYS_UNLOCK_FILE_REQUEST unlockReq = {
        sizeof(unlockReq),
        file,
        SYS_FILE_LOCK_FLAG_NONE,
        LOCK_OFFSET,
        LOCK_LENGTH,
    };
    s = SysUnlockFile(&unlockReq);
    if (s != NTLSTATUS_NOT_FOUND) fail_status("unlock missing range", s);

    lockReq.Length = LOCK_LENGTH;
    lockReq.FileHandle = 0xeeeeeeeeu;
    s = SysLockFile(&lockReq);
    if (s != NTLSTATUS_INVALID_HANDLE) fail_status("bad lock handle", s);
}

// Program entry point.
int main(void) {
    SYS_PEB* peb = SysGetPeb();
    if (peb && peb->CommandLine.Data && peb->CommandLine.Length != 0) {
        char mode[CHILD_PREFIX_MAX];
        char path[CHILD_PATH_MAX];
        if (parse_child_command(peb->CommandLine, mode, sizeof(mode), path, sizeof(path)) &&
            is_child_mode(mode)) {
            run_child(peb->CommandLine);
        }
    }

    print("file_lock_smoke: start\n");

    uint32_t file = 0;
    const char* path = 0;
    uint32_t s = create_temp_file(&file, &path);
    if (s != NTLSTATUS_SUCCESS) fail_status("create temp", s);

    test_validation(file);

    s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, 0);
    if (s != NTLSTATUS_SUCCESS) fail_status("exclusive parent lock", s);
    run_child_expect_success("excl-blocked", path);
    run_child_expect_success("excl-timeout", path);
    run_child_expect_success("excl-nonoverlap", path);
    s = unlock_range(file, LOCK_OFFSET, LOCK_LENGTH);
    if (s != NTLSTATUS_SUCCESS) fail_status("exclusive parent unlock", s);

    s = lock_range(file, SYS_FILE_LOCK_SHARED, LOCK_OFFSET, LOCK_LENGTH, 0);
    if (s != NTLSTATUS_SUCCESS) fail_status("shared parent lock", s);
    run_child_expect_success("shared-ok", path);
    run_child_expect_success("excl-blocked", path);
    s = unlock_range(file, LOCK_OFFSET, LOCK_LENGTH);
    if (s != NTLSTATUS_SUCCESS) fail_status("shared parent unlock", s);

    s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, 0);
    if (s != NTLSTATUS_SUCCESS) fail_status("blocking setup lock", s);
    SYS_PEB* selfPeb = SysGetPeb();
    if (!selfPeb || !selfPeb->ImagePath.Data || selfPeb->ImagePath.Length == 0) fail("missing self image");
    char command[CHILD_PREFIX_MAX + CHILD_PATH_MAX];
    build_child_command(command, sizeof(command), "excl-wait", path);
    uint32_t child = 0;
    SYS_CREATE_PROCESS_REQUEST createReq = { selfPeb->ImagePath, SysSvFromCstr(command), &child };
    s = SysCreateProcess(&createReq);
    if (s != NTLSTATUS_SUCCESS) fail_status("create blocking child", s);
    SysSleep(30);
    s = unlock_range(file, LOCK_OFFSET, LOCK_LENGTH);
    if (s != NTLSTATUS_SUCCESS) fail_status("wake unlock", s);
    s = SysWait(child, SYS_WAIT_FLAG_NONE);
    if (s != NTLSTATUS_SUCCESS) fail_status("wait blocking child", s);
    int32_t exitCode = 0;
    s = SysGetProcessExitCode(child, &exitCode);
    if (s != NTLSTATUS_SUCCESS) fail_status("query blocking child", s);
    SysCloseHandle(child);
    if (exitCode != 0) fail("blocking child failed");

    run_child_expect_success("hold-exit", path);
    s = lock_range(file, SYS_FILE_LOCK_EXCLUSIVE, LOCK_OFFSET, LOCK_LENGTH, 0);
    if (s != NTLSTATUS_SUCCESS) fail_status("exit released lock", s);
    s = unlock_range(file, LOCK_OFFSET, LOCK_LENGTH);
    if (s != NTLSTATUS_SUCCESS) fail_status("exit release cleanup unlock", s);

    SysCloseHandle(file);
    delete_path(path);

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