#include <stdio.h>
#include <windows.h>

// 関数のプロトタイプ宣言
ULONGLONG GetTotalFileSize(LPCWSTR folderPath);

int wmain() {
    LPCWSTR folderPath = 
        L"C:\\Users\\SEEDAGX\\source\\repos\\FolderSize\\FolderSize\\test\\"; // 対象のフォルダのワイド文字列パスを指定

    ULONGLONG totalSize = GetTotalFileSize(folderPath);

    if (totalSize != 0) {
        wprintf(L"Total size of files in %s: %llu bytes\n", folderPath, totalSize);
    }
    else {
        wprintf(L"Error calculating total size.\n");
    }

    return 0;
}

ULONGLONG GetTotalFileSize(LPCWSTR folderPath) {
    WIN32_FIND_DATA findFileData;
    WCHAR filePath[MAX_PATH];

    if (wcscpy_s(filePath, MAX_PATH, folderPath) == 0 &&
        wcscat_s(filePath, MAX_PATH, L"\\*") == 0) {

        HANDLE hFind = FindFirstFile(filePath, &findFileData);

        if (hFind == INVALID_HANDLE_VALUE) {
            return 0;
        }

        ULONGLONG totalSize = 0;

        do {
            if (!(findFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) {
                ULONGLONG fileSize = ((ULONGLONG)findFileData.nFileSizeHigh << 32) | findFileData.nFileSizeLow;
                totalSize += fileSize;
            }
        } while (FindNextFile(hFind, &findFileData) != 0);

        FindClose(hFind);

        return totalSize;
    }
    else {
        // エラー処理: フォルダパスが長すぎる場合など
        return 0;
    }
}