package storage

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"io"
	"os"
	"path/filepath"

	"mstore/app/logger"
	"mstore/pkg/auxuuid"
)

type Storage struct {
	basepath string
	logg     *logger.Logger
}

func NewStorage(basepath string) *Storage {
	res := &Storage{
		basepath: basepath,
	}
	res.logg = logger.NewLogger("storage")
	return res
}

func (store *Storage) GetFileReader(collection, filename string) (io.ReadCloser, error) {
	var err error
	var res io.ReadCloser

	filename = filepath.Join(store.basepath, collection, filename)
	file, err := os.OpenFile(filename, os.O_RDONLY, 0)
	if err != nil {
		return res, err
	}
	res = file
	return res, err
}

func (store *Storage) HardlinkFile(tmpname, collection, filename string) error {
	var err error
	dirname := filepath.Join(store.basepath, collection)
	err = os.MkdirAll(dirname, 0750)
	if err != nil {
		return err
	}

	filename = filepath.Join(store.basepath, collection, filename)
	os.Remove(filename) // TODO

	err = os.Link(tmpname, filename)
	if err != nil {
		return err
	}
	err = os.Remove(tmpname)
	if err != nil {
		return err
	}
	return err
}

func (store *Storage) WriteTempFile(source io.Reader) (string, int64, string, error) {
	var err error
	var size int64
	var digest string

	tmpname := auxuuid.NewUUID()
	tmpname = fmt.Sprintf("file-%s.tmp", tmpname)
	tmppath := filepath.Join(store.basepath, tmpname)

	file, err := os.OpenFile(tmppath, os.O_WRONLY|os.O_CREATE, 0640)
	if err != nil {
		return tmppath, size, digest, err
	}
	defer file.Close()

	hasher := sha256.New()
	writer := io.MultiWriter(file, hasher)

	size, err = io.Copy(writer, source)
	if err != nil {
		return tmppath, size, digest, err
	}
	digest = hex.EncodeToString(hasher.Sum(nil))
	digest = fmt.Sprintf("sha256:%s", digest)

	return tmppath, size, digest, err
}

func (store *Storage) DeleteFile(collection, filename string) error {
	var err error
	filename = filepath.Join(store.basepath, collection, filename)
	err = os.Remove(filename)
	if err != nil {
		return err
	}

	dirname := filepath.Join(store.basepath, collection)
	err = os.RemoveAll(dirname)
	if err != nil {
		return err
	}
	return err
}