package multisetstore

import (
	"github.com/kaspanet/kaspad/domain/consensus/model"
	"github.com/kaspanet/kaspad/domain/consensus/model/externalapi"
	"github.com/kaspanet/kaspad/domain/consensus/utils/dbkeys"
)

var bucket = dbkeys.MakeBucket([]byte("multisets"))

// multisetStore represents a store of Multisets
type multisetStore struct {
	staging map[externalapi.DomainHash]model.Multiset
}

// New instantiates a new MultisetStore
func New() model.MultisetStore {
	return &multisetStore{
		staging: make(map[externalapi.DomainHash]model.Multiset),
	}
}

// Stage stages the given multiset for the given blockHash
func (ms *multisetStore) Stage(blockHash *externalapi.DomainHash, multiset model.Multiset) {
	ms.staging[*blockHash] = multiset
}

func (ms *multisetStore) IsStaged() bool {
	return len(ms.staging) != 0
}

func (ms *multisetStore) Discard() {
	ms.staging = make(map[externalapi.DomainHash]model.Multiset)
}

func (ms *multisetStore) Commit(dbTx model.DBTransaction) error {
	for hash, multiset := range ms.staging {
		err := dbTx.Put(ms.hashAsKey(&hash), ms.serializeMultiset(multiset))
		if err != nil {
			return err
		}
	}

	ms.Discard()
	return nil
}

// Get gets the multiset associated with the given blockHash
func (ms *multisetStore) Get(dbContext model.DBReader, blockHash *externalapi.DomainHash) (model.Multiset, error) {
	if multiset, ok := ms.staging[*blockHash]; ok {
		return multiset, nil
	}

	multisetBytes, err := dbContext.Get(ms.hashAsKey(blockHash))
	if err != nil {
		return nil, err
	}

	return ms.deserializeMultiset(multisetBytes)
}

// Delete deletes the multiset associated with the given blockHash
func (ms *multisetStore) Delete(dbTx model.DBTransaction, blockHash *externalapi.DomainHash) error {
	if _, ok := ms.staging[*blockHash]; ok {
		delete(ms.staging, *blockHash)
		return nil
	}
	return dbTx.Delete(ms.hashAsKey(blockHash))
}

func (ms *multisetStore) hashAsKey(hash *externalapi.DomainHash) model.DBKey {
	return bucket.Key(hash[:])
}

func (ms *multisetStore) serializeMultiset(multiset model.Multiset) []byte {
	panic("implement me")
}

func (ms *multisetStore) deserializeMultiset(multisetBytes []byte) (model.Multiset, error) {
	panic("implement me")
}