// Current-directory PEB cache smoke test.
// Verifies that SysSetCwd updates the user-visible PEB cache without a getter syscall.

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

// 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(int code) {
    for (;;) SysExitProcess(code);
}

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

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

// Sets the current directory to one native path.
static void set_cwd_or_fail(const char* path, const char* what) {
    SYS_PATH_REQUEST req = { SysSvFromCstr(path) };
    uint32_t status = SysSetCwd(&req);
    if (status != NTLSTATUS_SUCCESS) fail_status(what, status);
}

// Verifies the current-directory PEB view against one native path.
static void expect_cwd(const char* expected) {
    SYS_STRING_VIEW cwd = SysGetCurrentDirectoryView();
    size_t expectedLen = strlen(expected);
    if (cwd.Length != expectedLen) fail("cwd length mismatch");
    if (cwd.Length && !cwd.Data) fail("cwd data missing");
    if (cwd.Length && memcmp(cwd.Data, expected, cwd.Length) != 0) fail("cwd value mismatch");
}

// Program entry point.
int main(void) {
    static const char rootPath[] = "0:/";
    static const char tempDir[] = "0:/cwd_peb_smoke_dir";

    print("cwd_peb_smoke: start\n");

    SYS_PEB* peb = SysGetPeb();
    if (!peb) fail("peb missing");
    if (peb->Magic != SYS_PEB_MAGIC) fail("peb magic mismatch");
    if (peb->Version != SYS_ENV_VERSION) fail("peb version mismatch");

    set_cwd_or_fail(rootPath, "set root cwd");
    expect_cwd(rootPath);

    SYS_PATH_REQUEST dirReq = { SysSvFromCstr(tempDir) };
    uint32_t status = SysRemoveDir(&dirReq);
    if (status != NTLSTATUS_SUCCESS && status != NTLSTATUS_NOT_FOUND)
        fail_status("remove stale temp dir", status);

    status = SysCreateDir(&dirReq);
    if (status != NTLSTATUS_SUCCESS) fail_status("create temp dir", status);

    set_cwd_or_fail(tempDir, "set temp cwd");
    expect_cwd(tempDir);

    set_cwd_or_fail(rootPath, "restore root cwd");
    expect_cwd(rootPath);

    status = SysRemoveDir(&dirReq);
    if (status != NTLSTATUS_SUCCESS) fail_status("remove temp dir", status);

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