// POSIX compatibility support for posix dir.

#include <string.h>
#include <ntlite/syscall.h>
#include <stdlib.h>
#include "posix.h"
#include "posix_path.h"

typedef SYS_DIR_ENTRY KDIR_ENTRY;


#define KATTR_DIR  0x10

// Implements the chdir operation.
__declspec(dllexport) int chdir(const char* path) {
    char native[512];
    PosixTranslatePath(path, native, sizeof(native));
    SYS_PATH_REQUEST req = { SysSvFromCstr(native) };
    uint32_t s = SysSetCwd(&req);
    if (s != 0) { errno = ENOENT; return -1; }
    return 0;
}

// Implements the getcwd operation.
__declspec(dllexport) char* getcwd(char* buf, size_t size) {
    if (!buf || size == 0) { errno = EINVAL; return (char*)0; }
    char native[512];
    size_t nativeLen = 0;
    SYS_GET_CWD_REQUEST req = { native, sizeof(native) - 1, &nativeLen };
    uint32_t s = SysGetCwd(&req);
    if (s == 0) native[nativeLen] = '\0';
    if (s != 0) { errno = ERANGE; return (char*)0; }
    NativeToPosix(native, buf, size);
    return buf;
}

// Implements the opendir operation.
__declspec(dllexport) DIR* opendir(const char* path) {
    char native[512];
    PosixTranslatePath(path, native, sizeof(native));
    uint32_t kh;
    SYS_PATH_HANDLE_REQUEST req = { SysSvFromCstr(native), &kh };
    uint32_t s = SysOpenDir(&req);
    if (s != 0) { errno = ENOENT; return (DIR*)0; }

    // Allocate DIR on the kernel heap (malloc) so it outlives the stack.
    DIR* d = (DIR*)malloc(sizeof(DIR));
    if (!d) { SysCloseHandle(kh); errno = ENOMEM; return (DIR*)0; }
    d->KHandle = kh;
    d->Valid   = false;
    return d;
}

// Implements the readdir operation.
__declspec(dllexport) struct dirent* readdir(DIR* d) {
    if (!d) { errno = EBADF; return (struct dirent*)0; }
    KDIR_ENTRY ke;
    uint32_t s = SysReadDir(d->KHandle, &ke);
    if (s != 0) return (struct dirent*)0;   // end of directory or error

    size_t len = strlen(ke.Name);
    if (len > NAME_MAX) len = NAME_MAX;
    memcpy(d->Current.d_name, ke.Name, len);
    d->Current.d_name[len] = '\0';
    d->Current.d_type = (ke.Attr & KATTR_DIR) ? DT_DIR : DT_REG;
    d->Valid = true;
    return &d->Current;
}

// Implements the closedir operation.
__declspec(dllexport) int closedir(DIR* d) {
    if (!d) { errno = EBADF; return -1; }
    SysCloseHandle(d->KHandle);
    free(d);
    return 0;
}