// Copyright (c) 2023 Proton AG
//
// This file is part of Proton Mail Bridge.
//
// Proton Mail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Proton Mail Bridge is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Proton Mail Bridge.  If not, see <https://www.gnu.org/licenses/>.

package bridge

import (
	"fmt"
	"io"
	"os"
	"path/filepath"
)

func moveDir(from, to string) error {
	entries, err := os.ReadDir(from)
	if err != nil {
		return err
	}

	for _, entry := range entries {
		if entry.IsDir() {
			if err := os.Mkdir(filepath.Join(to, entry.Name()), 0o700); err != nil {
				return err
			}

			if err := moveDir(filepath.Join(from, entry.Name()), filepath.Join(to, entry.Name())); err != nil {
				return err
			}

			if err := os.RemoveAll(filepath.Join(from, entry.Name())); err != nil {
				return err
			}
		} else {
			if err := moveFile(filepath.Join(from, entry.Name()), filepath.Join(to, entry.Name())); err != nil {
				return err
			}
		}
	}

	return os.Remove(from)
}

func moveFile(from, to string) error {
	if err := os.MkdirAll(filepath.Dir(to), 0o700); err != nil {
		return err
	}

	if err := os.Rename(from, to); err != nil {
		return err
	}

	return nil
}

func copyDir(from, to string) error {
	entries, err := os.ReadDir(from)
	if err != nil {
		return err
	}
	if err := createIfNotExists(to, 0o700); err != nil {
		return err
	}
	for _, entry := range entries {
		sourcePath := filepath.Join(from, entry.Name())
		destPath := filepath.Join(to, entry.Name())

		if entry.IsDir() {
			if err := copyDir(sourcePath, destPath); err != nil {
				return err
			}
		} else {
			if err := copyFile(sourcePath, destPath); err != nil {
				return err
			}
		}
	}
	return nil
}

func copyFile(srcFile, dstFile string) error {
	out, err := os.Create(filepath.Clean(dstFile))
	defer func(out *os.File) {
		_ = out.Close()
	}(out)

	if err != nil {
		return err
	}

	in, err := os.Open(filepath.Clean(srcFile))
	defer func(in *os.File) {
		_ = in.Close()
	}(in)

	if err != nil {
		return err
	}

	_, err = io.Copy(out, in)
	if err != nil {
		return err
	}

	return nil
}

func exists(filePath string) bool {
	if _, err := os.Stat(filePath); os.IsNotExist(err) {
		return false
	}

	return true
}

func createIfNotExists(dir string, perm os.FileMode) error {
	if exists(dir) {
		return nil
	}

	if err := os.MkdirAll(dir, perm); err != nil {
		return fmt.Errorf("failed to create directory: '%s', error: '%s'", dir, err.Error())
	}

	return nil
}