#!python
# -*- mode: python; Encoding: utf-8; coding: utf-8 -*-
# Last updated: <2025/12/06 13:52:05 +0900>
"""
ctypes sample. use GetOpenFileNameW()

Python: ctypesパターン集 #Windows - Qiita
https://qiita.com/everylittle/items/6e18ba23f38502c18f3e

How to get null terminated strings from a buffer? - Python Help - Discussions on Python.org
https://discuss.python.org/t/how-to-get-null-terminated-strings-from-a-buffer/26904/3

Windows11 x64 25H2 + Python 3.10.10 64bit
"""

import ctypes
import os

# ファイルダイアログの動作を指定するための定数
OFN_ALLOWMULTISELECT = 0x00000200
OFN_FILEMUSTEXIST = 0x00001000
OFN_PATHMUSTEXIST = 0x00000800
OFN_EXPLORER = 0x00080000

# 受け取るファイルパスを格納するバッファのサイズ
BUFFER_SIZE = 32768


class OPENFILENAME(ctypes.Structure):
    """GetOpenFileNameW()を呼び出すために必要な構造体を定義"""

    _fields_ = [
        ("lStructSize", ctypes.c_uint32),
        ("hwndOwner", ctypes.c_void_p),
        ("hInstance", ctypes.c_void_p),
        ("lpstrFilter", ctypes.c_wchar_p),
        ("lpstrCustomFilter", ctypes.c_wchar_p),
        ("nMaxCustFilter", ctypes.c_uint32),
        ("nFilterIndex", ctypes.c_uint32),
        ("lpstrFile", ctypes.c_wchar_p),
        ("nMaxFile", ctypes.c_uint32),
        ("lpstrFileTitle", ctypes.c_wchar_p),
        ("nMaxFileTitle", ctypes.c_uint32),
        ("lpstrInitialDir", ctypes.c_wchar_p),
        ("lpstrTitle", ctypes.c_wchar_p),
        ("Flags", ctypes.c_uint32),
        ("nFileOffset", ctypes.c_uint16),
        ("nFileExtension", ctypes.c_uint16),
        ("lpstrDefExt", ctypes.c_wchar_p),
        ("lCustData", ctypes.c_void_p),
        ("lpfnHook", ctypes.c_void_p),
        ("lpTemplateName", ctypes.c_wchar_p),
        ("pvReserved", ctypes.c_void_p),
        ("dwReserved", ctypes.c_uint32),
        ("FlagsEx", ctypes.c_uint32),
    ]


def get_openfilename(initial_dir=None, filters=None):
    """ファイルダイアログを開いて複数ファイルを選択"""

    comdlg32 = ctypes.WinDLL("comdlg32")
    comdlg32.GetOpenFileNameW.restype = ctypes.c_bool
    comdlg32.GetOpenFileNameW.argtypes = (ctypes.POINTER(OPENFILENAME),)

    ofn = OPENFILENAME()
    lenFilenameBufferInChars = BUFFER_SIZE
    buf = ctypes.create_unicode_buffer(lenFilenameBufferInChars)

    ofn.lStructSize = ctypes.sizeof(OPENFILENAME)

    # ファイル種類のフィルターを設定
    if filters:
        ofn.lpstrFilter = "\0".join(filters) + "\0\0"
    else:
        ofn.lpstrFilter = "All files {*.*}\0*.*\0\0"

    if initial_dir:
        ofn.lpstrInitialDir = initial_dir

    ofn.lpstrFile = ctypes.cast(buf, ctypes.c_wchar_p)
    ofn.nMaxFile = lenFilenameBufferInChars
    ofn.lpstrTitle = "Select file"
    ofn.Flags = (
        OFN_ALLOWMULTISELECT | OFN_EXPLORER | OFN_FILEMUSTEXIST | OFN_PATHMUSTEXIST
    )

    ret = comdlg32.GetOpenFileNameW(ofn)
    files = []
    if ret:
        # 得られたファイルパスを分割してリストにする
        s = buf[:].rstrip("\0")
        path = s[: ofn.nFileOffset].rstrip("\0")
        filenames = s[ofn.nFileOffset :].split("\0")
        files = [os.path.abspath(os.path.join(path, f)) for f in filenames]

        # リストの形でファイルパス群を返す
        return files

    return []


def main():
    filters = [
        "All files {*.*}",
        "*.*",
        "Text {*.txt}",
        "*.txt",
    ]

    homedir = os.path.expanduser("~")
    print(f"Initial Directory : {homedir}")

    files = get_openfilename(initial_dir=homedir, filters=filters)
    if files:
        print(files)
    else:
        print("Cancel.")


if __name__ == "__main__":
    main()