package client

//
// Storage
//
import (
	"crypto/sha256"
	"encoding/json"
	"path/filepath"

	"forge.redroom.link/yves/meowlib"
	"github.com/dgraph-io/badger"
)

type PeerStorage struct {
	DbFile string `json:"db_file,omitempty"`
	db     *badger.DB
	cache  map[string]*Peer
}

// Open a badger database from struct PeerStorage
func (ps *PeerStorage) open() error {

	opts := badger.DefaultOptions(filepath.Join(GetConfig().StoragePath, GetConfig().GetIdentity().Uuid, ps.DbFile))
	opts.Logger = nil
	var err error
	ps.db, err = badger.Open(opts)
	if err != nil {
		return err
	}
	return nil
}

// Store function StorePeer stores a peer in a badger database with Peer.Uid as key
func (ps *PeerStorage) StorePeer(peer *Peer) error {
	err := ps.open()
	if err != nil {
		return err
	}
	defer ps.close()
	// first marshal the Peer to bytes with protobuf
	jsonsrv, err := json.Marshal(peer)
	if err != nil {
		return err
	}
	password := GetConfig().memoryPassword
	if peer.dbPassword != "" {
		password = peer.dbPassword
	}
	data, err := meowlib.SymEncrypt(password, jsonsrv)
	if err != nil {
		return err
	}
	shakey := sha256.Sum256([]byte(peer.Uid))
	key := shakey[:]
	// then store it in the database
	return ps.db.Update(func(txn *badger.Txn) error {
		return txn.Set(key, data)
	})

}

// LoadPeer function loads a Peer from a badger database with Peer.GetUid() as key
func (ps *PeerStorage) LoadPeer(uid string, password string) (*Peer, error) {
	var peer Peer
	err := ps.open()
	if err != nil {
		return nil, err
	}
	defer ps.close()
	shakey := sha256.Sum256([]byte(uid))
	key := shakey[:]
	err = ps.db.View(func(txn *badger.Txn) error {
		item, err := txn.Get(key)
		if err != nil {
			return err
		}
		return item.Value(func(val []byte) error {
			jsonsrv, err := meowlib.SymDecrypt(password, val)
			if err != nil {
				return err
			}
			return json.Unmarshal(jsonsrv, &peer)
		})
	})
	return &peer, err
}

// DeletePeer function deletes a Peer from a badger database with Peer.GetUid() as key
func (ps *PeerStorage) DeletePeer(uid string) error {
	err := ps.open()
	if err != nil {
		return err
	}
	defer ps.close()
	shakey := sha256.Sum256([]byte(uid))
	key := shakey[:]
	return ps.db.Update(func(txn *badger.Txn) error {
		return txn.Delete(key)
	})
}

// LoadAllPeers function loads all Peers from a badger database
func (ps *PeerStorage) LoadAllPeers(password string) ([]*Peer, error) {
	var peers []*Peer
	err := ps.open()
	if err != nil {
		return nil, err
	}
	defer ps.close()
	err = ps.db.View(func(txn *badger.Txn) error {
		opts := badger.DefaultIteratorOptions
		opts.PrefetchSize = 10
		it := txn.NewIterator(opts)
		defer it.Close()
		for it.Rewind(); it.Valid(); it.Next() {
			item := it.Item()
			var sc Peer
			err := item.Value(func(val []byte) error {
				jsonsrv, err := meowlib.SymDecrypt(password, val)
				if err != nil {
					return err
				}
				return json.Unmarshal(jsonsrv, &sc)
			})
			if err != nil {
				peers = append(peers, &sc)
			}
		}
		return nil
	})
	return peers, err
}

// LoadPeersFromUids function loads Peers with id in []Uid parameter from a badger database
func (ps *PeerStorage) LoadPeersFromUids(uids []string, password string) ([]*Peer, error) {
	var peers []*Peer
	err := ps.open()
	if err != nil {
		return nil, err
	}
	defer ps.close()
	err = ps.db.View(func(txn *badger.Txn) error {
		for _, uid := range uids {
			shakey := sha256.Sum256([]byte(uid))
			key := shakey[:]
			item, err := txn.Get(key)
			if err != nil {
				return err
			}
			var sc Peer
			err = item.Value(func(val []byte) error {
				jsonsrv, err := meowlib.SymDecrypt(password, val)
				if err != nil {
					return err
				}
				return json.Unmarshal(jsonsrv, &sc)
			})
			if err == nil {
				peers = append(peers, &sc)
			}

		}
		return nil
	})
	return peers, err
}

// close a badger database
func (ps *PeerStorage) close() {
	ps.db.Close()
}