package shrty

import (
	"bytes"
	"encoding/json"
	"errors"
	"io"
	"os"
)

type DB struct {
	Path string
	Store *Store
}

type Store struct {
	Token map[string]*Data  `json:"token"` // [token]*Data
	Url   map[string]string `json:"url"` // [hash]token
}

var (
	ErrNotFound    = errors.New("Url not Found")
	ErrCreateToken = errors.New("There are some problems while creating Token")
	ErrNoUrl       = errors.New("String is no Url!")
)

// Open up
func Open(path string) (*DB, error) {
	s := DB{Path:  path,
		Store: &Store{
			Token: make(map[string]*Data),
			Url: make(map[string]string)},
	}

	// Open db ore create if not exist!
	if db, err := os.OpenFile(s.Path, os.O_RDWR|os.O_CREATE, 0644); err == nil {
		json.Unmarshal(StreamToByte(db), &s.Store)
		db.Close()
		return &s, nil
	} else {
		return &s, err
	}
}

func (s *DB) Remove(URL string) error {
	return nil
}

func (s *DB) Save() error {
	if db, err := os.OpenFile(s.Path, os.O_RDWR|os.O_CREATE, 0644); err == nil {
		b, err := json.Marshal(s.Store)
		db.Write(b)
		db.Close()
		return err
	} else {
		return err
	}
}

func StreamToByte(stream io.Reader) []byte {
	buf := new(bytes.Buffer)
	buf.ReadFrom(stream)
	return buf.Bytes()
}