#ifndef FILESYSTEM_H
#define FILESYSTEM_H

#include <cstdio>
#include <functional>
#include "bufferio.h"

#ifndef _WIN32
#include <dirent.h>
#include <sys/stat.h>
#include <vector>
#include <algorithm>
#endif

#ifdef _WIN32

#define NOMINMAX
#include <Windows.h>

class FileSystem {
public:
	static void SafeFileName(wchar_t* wfile) {
		while((wfile = std::wcspbrk(wfile, L"<>:\"/\\|?*")) != nullptr)
			*wfile++ = '_';
	}

	static bool IsFileExists(const wchar_t* wfile) {
		DWORD attr = GetFileAttributesW(wfile);
		return attr != INVALID_FILE_ATTRIBUTES && !(attr & FILE_ATTRIBUTE_DIRECTORY);
	}

	static bool IsFileExists(const char* file) {
		wchar_t wfile[1024];
		BufferIO::DecodeUTF8(file, wfile);
		return IsFileExists(wfile);
	}

	static bool IsDirExists(const wchar_t* wdir) {
		DWORD attr = GetFileAttributesW(wdir);
		return attr != INVALID_FILE_ATTRIBUTES && (attr & FILE_ATTRIBUTE_DIRECTORY);
	}

	static bool IsDirExists(const char* dir) {
		wchar_t wdir[1024];
		BufferIO::DecodeUTF8(dir, wdir);
		return IsDirExists(wdir);
	}

	static bool MakeDir(const wchar_t* wdir) {
		return CreateDirectoryW(wdir, nullptr);
	}

	static bool MakeDir(const char* dir) {
		wchar_t wdir[1024];
		BufferIO::DecodeUTF8(dir, wdir);
		return MakeDir(wdir);
	}

	static bool Rename(const wchar_t* woldname, const wchar_t* wnewname) {
		return MoveFileW(woldname, wnewname);
	}

	static bool Rename(const char* oldname, const char* newname) {
		wchar_t woldname[1024];
		wchar_t wnewname[1024];
		BufferIO::DecodeUTF8(oldname, woldname);
		BufferIO::DecodeUTF8(newname, wnewname);
		return Rename(woldname, wnewname);
	}

	static bool DeleteDir(const wchar_t* wdir) {
		wchar_t pdir[256];
		BufferIO::CopyWideString(wdir, pdir);
		SHFILEOPSTRUCTW lpFileOp{};
		lpFileOp.hwnd = nullptr;
		lpFileOp.wFunc = FO_DELETE;
		lpFileOp.pFrom = pdir;
		lpFileOp.pTo = 0;
		lpFileOp.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_SILENT;
		return SHFileOperationW(&lpFileOp) == 0;
	}

	static bool DeleteDir(const char* dir) {
		wchar_t wdir[1024];
		BufferIO::DecodeUTF8(dir, wdir);
		return DeleteDir(wdir);
	}

	static void TraversalDir(const wchar_t* wpath, const std::function<void(const wchar_t*, bool)>& cb) {
		wchar_t findstr[1024];
		std::swprintf(findstr, sizeof findstr / sizeof findstr[0], L"%ls/*", wpath);
		WIN32_FIND_DATAW fdataw;
		HANDLE fh = FindFirstFileW(findstr, &fdataw);
		if(fh == INVALID_HANDLE_VALUE)
			return;
		do {
			if(std::wcscmp(fdataw.cFileName, L".") && std::wcscmp(fdataw.cFileName, L".."))
				cb(fdataw.cFileName, (fdataw.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY));
		} while(FindNextFileW(fh, &fdataw));
		FindClose(fh);
	}

	static void TraversalDir(const char* path, const std::function<void(const char*, bool)>& cb) {
		wchar_t wpath[1024];
		BufferIO::DecodeUTF8(path, wpath);
		TraversalDir(wpath, [&cb](const wchar_t* wname, bool isdir) {
			char name[1024];
			BufferIO::EncodeUTF8(wname, name);
			cb(name, isdir);
		});
	}
};

#else

class FileSystem {
public:
	static void SafeFileName(wchar_t* wfile) {
		while((wfile = std::wcspbrk(wfile, L"/")) != nullptr)
			*wfile++ = '_';
	}

	static bool IsFileExists(const char* file) {
		struct stat fileStat;
		return (stat(file, &fileStat) == 0) && !S_ISDIR(fileStat.st_mode);
	}

	static bool IsFileExists(const wchar_t* wfile) {
		char file[1024];
		BufferIO::EncodeUTF8(wfile, file);
		return IsFileExists(file);
	}

	static bool IsDirExists(const char* dir) {
		struct stat fileStat;
		return (stat(dir, &fileStat) == 0) && S_ISDIR(fileStat.st_mode);
	}

	static bool IsDirExists(const wchar_t* wdir) {
		char dir[1024];
		BufferIO::EncodeUTF8(wdir, dir);
		return IsDirExists(dir);
	}

	static bool MakeDir(const char* dir) {
		return mkdir(dir, 0775) == 0;
	}

	static bool MakeDir(const wchar_t* wdir) {
		char dir[1024];
		BufferIO::EncodeUTF8(wdir, dir);
		return MakeDir(dir);
	}

	static bool Rename(const wchar_t* woldname, const wchar_t* wnewname) {
		char oldname[1024];
		char newname[1024];
		BufferIO::EncodeUTF8(woldname, oldname);
		BufferIO::EncodeUTF8(wnewname, newname);
		return Rename(oldname, newname);
	}

	static bool Rename(const char* oldname, const char* newname) {
		return rename(oldname, newname) == 0;
	}

	static bool DeleteDir(const wchar_t* wdir) {
		char dir[1024];
		BufferIO::EncodeUTF8(wdir, dir);
		return DeleteDir(dir);
	}

	static bool DeleteDir(const char* dir) {
		bool success = true;
		TraversalDir(dir, [dir, &success](const char *name, bool isdir) {
			char full_path[1024];
			int len = std::snprintf(full_path, sizeof full_path, "%s/%s", dir, name);
			if (len < 0 || len >= (int)(sizeof full_path)) {
				success = false;
				return;
			}
			if (isdir)
			{
				if(!DeleteDir(full_path))
					success = false;
			}
			else
			{
				if(unlink(full_path) != 0)
					success = false;
			}
		});
		if (rmdir(dir) != 0)
			success = false;
		return success;
	}

	struct file_unit {
		std::string filename;
		bool is_dir;
	};

	static void TraversalDir(const char* path, const std::function<void(const char*, bool)>& cb) {
		DIR* dir = nullptr;
		struct dirent* dirp = nullptr;
		if((dir = opendir(path)) == nullptr)
			return;
		struct stat fileStat;
		std::vector<file_unit> file_list;
		while((dirp = readdir(dir)) != nullptr) {
			file_unit funit;
			char fname[1024];
			int len = std::snprintf(fname, sizeof fname, "%s/%s", path, dirp->d_name);
			if (len < 0 || len >= (int)(sizeof fname))
				continue;
			stat(fname, &fileStat);
			funit.filename = std::string(dirp->d_name);
			funit.is_dir = S_ISDIR(fileStat.st_mode);
			if(funit.is_dir && (std::strcmp(dirp->d_name, ".") == 0 || std::strcmp(dirp->d_name, "..") == 0))
				continue;
			file_list.push_back(funit);
		}
		closedir(dir);
		std::sort(file_list.begin(), file_list.end(), TraversalDirSort);
		for (file_unit funit : file_list)
			cb(funit.filename.c_str(), funit.is_dir);
	}

	static bool TraversalDirSort(file_unit file1, file_unit file2) {
		if(file1.is_dir != file2.is_dir) {
			return file2.is_dir;
		} else {
			return file1.filename < file2.filename;
		}
	}

	static void TraversalDir(const wchar_t* wpath, const std::function<void(const wchar_t*, bool)>& cb) {
		char path[1024];
		BufferIO::EncodeUTF8(wpath, path);
		TraversalDir(path, [&cb](const char* name, bool isdir) {
			wchar_t wname[1024];
			BufferIO::DecodeUTF8(name, wname);
			cb(wname, isdir);
		});
	}
};

#endif // _WIN32

#endif //FILESYSTEM_H
