package client

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

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

type ServerStorage struct {
	DbFile string `json:"db_file,omitempty"`
	db     *badger.DB
}

// Open a badger database from struct ServerStorage
func (ss *ServerStorage) open() error {
	opts := badger.DefaultOptions(ss.DbFile)
	opts.Logger = nil
	var err error
	ss.db, err = badger.Open(opts)
	if err != nil {
		return err
	}
	return nil
}

// Store function StoreServer stores a server in a badger database with Server.GetUid() as key
func (ss *ServerStorage) StoreServer(sc *Server) error {
	err := ss.open()
	if err != nil {
		return err
	}
	defer ss.close()
	// first marshal the Server to bytes with protobuf
	jsonsrv, err := json.Marshal(sc)
	if err != nil {
		return err
	}
	data, err := meowlib.SymEncrypt(GetConfig().memoryPassword, jsonsrv)
	if err != nil {
		return err
	}
	shakey := sha256.Sum256([]byte(sc.GetServerCard().GetUid()))
	key := shakey[:]
	// then store it in the database
	return ss.db.Update(func(txn *badger.Txn) error {
		return txn.Set(key, data)
	})

}

// LoadServer function loads a Server from a badger database with Server.GetUid() as key
func (ss *ServerStorage) LoadServer(uid string) (*Server, error) {
	var sc Server
	err := ss.open()
	if err != nil {
		return nil, err
	}
	defer ss.close()
	shakey := sha256.Sum256([]byte(uid))
	key := shakey[:]
	err = ss.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(GetConfig().memoryPassword, val)
			if err != nil {
				return err
			}
			return json.Unmarshal(jsonsrv, &sc)
		})
	})
	return &sc, err
}

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

// LoadAllServers function loads all Servers from a badger database
func (ss *ServerStorage) LoadAllServers() ([]*Server, error) {
	var scs []*Server
	err := ss.open()
	if err != nil {
		return nil, err
	}
	defer ss.close()
	err = ss.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 Server
			err := item.Value(func(val []byte) error {
				jsonsrv, err := meowlib.SymDecrypt(GetConfig().memoryPassword, val)
				if err != nil {
					return err
				}
				return json.Unmarshal(jsonsrv, &sc)
			})
			if err != nil {
				return err
			}
			scs = append(scs, &sc)
		}
		return nil
	})
	return scs, err
}

// LoadAllServers function loads all ServersCards from a badger database
func (ss *ServerStorage) LoadAllServerCards() ([]*meowlib.ServerCard, error) {
	var scs []*meowlib.ServerCard
	err := ss.open()
	if err != nil {
		return nil, err
	}
	defer ss.close()
	err = ss.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 Server
			err := item.Value(func(val []byte) error {
				jsonsrv, err := meowlib.SymDecrypt(GetConfig().memoryPassword, val)
				if err != nil {
					return err
				}
				return json.Unmarshal(jsonsrv, &sc)
			})
			if err != nil {
				return err
			}
			scs = append(scs, sc.GetServerCard())
		}
		return nil
	})
	return scs, err
}

// LoadServersFromUids function loads Servers with id in []Uid parameter from a badger database
func (ss *ServerStorage) LoadServersFromUids(uids []string) ([]*Server, error) {
	var scs []*Server
	err := ss.open()
	if err != nil {
		return nil, err
	}
	defer ss.close()
	err = ss.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 Server
			err = item.Value(func(val []byte) error {
				jsonsrv, err := meowlib.SymDecrypt(GetConfig().memoryPassword, val)
				if err != nil {
					return err
				}
				return json.Unmarshal(jsonsrv, &sc)
			})
			if err != nil {
				return err
			}
			scs = append(scs, &sc)
		}
		return nil
	})
	return scs, err
}

// LoadServersFromUids function loads Servers with id in []Uid parameter from a badger database
func (ss *ServerStorage) LoadServerCardsFromUids(uids []string) ([]*meowlib.ServerCard, error) {
	var scs []*meowlib.ServerCard
	err := ss.open()
	if err != nil {
		return nil, err
	}
	defer ss.close()
	err = ss.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 Server
			err = item.Value(func(val []byte) error {
				jsonsrv, err := meowlib.SymDecrypt(GetConfig().memoryPassword, val)
				if err != nil {
					return err
				}
				return json.Unmarshal(jsonsrv, &sc)
			})
			if err != nil {
				return err
			}
			scs = append(scs, sc.GetServerCard())
		}
		return nil
	})
	return scs, err
}

// close a badger database
func (ss *ServerStorage) close() {
	ss.db.Close()
}