import t, c
from stdint import *
import platmacro
import memhub
import os.path
import os._win32
import os._posix


# os package entry point
# Dispatches to _win32 or _posix backend based on platmacro.IS_WINDOWS
# os.path is for cross-platform pure string operations, can be used directly

# Module-level global MBuddy pointer (initialized by the user in main)
_mbuddy: memhub.MemBuddy | t.CPtr


# =============================================================================
# File/Directory Attribute Query
# =============================================================================

def exists(path: str) -> bool:
    """Check if the file/directory exists"""
    if platmacro.IS_WINDOWS:
        return os._win32.exists(path)
    return os._posix.exists(path)


def isdir(path: str) -> bool:
    """Check if the path is a directory"""
    if platmacro.IS_WINDOWS:
        return os._win32.isdir(path)
    return os._posix.isdir(path)


def isfile(path: str) -> bool:
    """Check if the path is a regular file"""
    if platmacro.IS_WINDOWS:
        return os._win32.isfile(path)
    return os._posix.isfile(path)


def getsize(path: str) -> t.CInt64T:
    """Returns the file size (in bytes). Returns -1 on failure."""
    if platmacro.IS_WINDOWS:
        return os._win32.getsize(path)
    return os._posix.getsize(path)


# =============================================================================
# Working Directory
# =============================================================================

def getcwd() -> str:
    """Return the current working directory (memory allocated via _mbuddy)"""
    if platmacro.IS_WINDOWS:
        return os._win32.getcwd()
    return os._posix.getcwd_impl()


def chdir(path: str) -> int:
    """Switch the current working directory. Returns 0 if successful, -1 if it fails."""
    if platmacro.IS_WINDOWS:
        return os._win32.chdir(path)
    return os._posix.chdir_impl(path)


# =============================================================================
# File/Directory Operations
# =============================================================================

def mkdir(path: str) -> int:
    """Create a directory. Returns 0 on success, -1 on failure."""
    if platmacro.IS_WINDOWS:
        return os._win32.mkdir(path)
    return os._posix.mkdir_impl(path)


def remove(path: str) -> int:
    """Delete the file. Returns 0 if successful, -1 if it fails."""
    if platmacro.IS_WINDOWS:
        return os._win32.remove(path)
    return os._posix.remove(path)


def rmdir(path: str) -> int:
    """Delete empty directories. Returns 0 if successful, -1 if it fails."""
    if platmacro.IS_WINDOWS:
        return os._win32.rmdir(path)
    return os._posix.rmdir_impl(path)


def rename(old_path: str, new_path: str) -> int:
    """Rename/move a file or directory. Returns 0 on success, -1 on failure."""
    if platmacro.IS_WINDOWS:
        return os._win32.rename(old_path, new_path)
    return os._posix.rename_impl(old_path, new_path)


def chmod(path: str, mode: int) -> int:
    """Modify file permissions. Returns 0 on success, -1 on failure.
       On Windows, only the read-only bit (S_IWUSR) is handled;
       On POSIX, full permission bits are used."""
    if platmacro.IS_WINDOWS:
        return os._win32.chmod(path, mode)
    return os._posix.chmod_impl(path, mode)


# =============================================================================
# Table of Contents Listing
# =============================================================================

def listdir(path: str, out_names: str, max_count: ULONG) -> ULONG:
    """列举目录下的文件/子目录名。
    out_names 为调用者提供的字符串指针数组（char**），每个元素指向一个文件名。
    文件名通过 _mbuddy 分配内存。
    max_count 为 out_names 数组最大容量。
    返回实际列举的条目数。失败返回 0。"""
    if platmacro.IS_WINDOWS:
        return os._win32.listdir(path, out_names, max_count)
    return os._posix.listdir(path, out_names, max_count)


# =============================================================================
# 命令执行
# =============================================================================

def system(cmd: str) -> int:
    """执行命令行命令（通过 C 运行时 system()）。
    命令输出直接到终端（继承父进程 stdout/stderr）。
    返回命令的退出码（0 表示成功）。"""
    if platmacro.IS_WINDOWS:
        return os._win32.system(cmd)
    return os._posix.system_impl(cmd)