package local

import (
	pkg "github.com/jkaninda/pg-bkup/pkg/storage"
	"io"
	"os"
	"path/filepath"
	"time"
)

/*
MIT License

Copyright (c) 2023 Jonas Kaninda

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

type localStorage struct {
	*pkg.Backend
}
type Config struct {
	LocalPath  string
	RemotePath string
}

// NewStorage creates new Storage
func NewStorage(conf Config) pkg.Storage {
	return &localStorage{
		Backend: &pkg.Backend{
			LocalPath:  conf.LocalPath,
			RemotePath: conf.RemotePath,
		},
	}
}

// Copy copies file to the local destination path
func (l localStorage) Copy(file string) error {
	if _, err := os.Stat(filepath.Join(l.LocalPath, file)); os.IsNotExist(err) {
		return err
	}
	err := copyFile(filepath.Join(l.LocalPath, file), filepath.Join(l.RemotePath, file))
	if err != nil {
		return err
	}
	return nil
}

// CopyFrom copies file from a Path to local path
func (l localStorage) CopyFrom(file string) error {
	if _, err := os.Stat(filepath.Join(l.RemotePath, file)); os.IsNotExist(err) {
		return err
	}
	err := copyFile(filepath.Join(l.RemotePath, file), filepath.Join(l.LocalPath, file))
	if err != nil {
		return err
	}
	return nil
}

// Prune deletes old backup created more than specified days
func (l localStorage) Prune(retentionDays int) error {
	currentTime := time.Now()
	// Delete file
	deleteFile := func(filePath string) error {
		err := os.Remove(filePath)
		return err
	}
	// Walk through the directory and delete files modified more than specified days ago
	err := filepath.Walk(l.RemotePath, func(filePath string, fileInfo os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		// Check if it's a regular file and if it was modified more than specified days ago
		if fileInfo.Mode().IsRegular() {
			timeDiff := currentTime.Sub(fileInfo.ModTime())
			if timeDiff.Hours() > 24*float64(retentionDays) {
				err := deleteFile(filePath)
				if err != nil {
					return err
				}
			}
		}
		return nil
	})
	if err != nil {
		return err
	}
	return nil
}

// Name returns the storage name
func (l localStorage) Name() string {
	return "local"
}

// copyFile copies file
func copyFile(src, dst string) error {
	in, err := os.Open(src)
	if err != nil {
		return err
	}
	defer func(in *os.File) {
		err := in.Close()
		if err != nil {
			return
		}
	}(in)

	out, err := os.Create(dst)
	if err != nil {
		return err
	}

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