package db

// db_get.go contains the basic access functions to the database.

import (
	"bytes"
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"math"

	"github.com/lbryio/herald.go/db/prefixes"
	"github.com/lbryio/herald.go/db/stack"
	"github.com/lbryio/lbcd/chaincfg/chainhash"
	"github.com/lbryio/lbcd/wire"
	"github.com/linxGnu/grocksdb"

	log "github.com/sirupsen/logrus"
)

// GetExpirationHeight returns the expiration height for the given height. Uses
// the original claim expiration time.
func GetExpirationHeight(lastUpdatedHeight uint32) uint32 {
	return GetExpirationHeightFull(lastUpdatedHeight, false)
}

// GetExpirationHeightFull returns the expiration height for the given height.
// Takes boolean to indicated whether to use extended or original expiration time.
func GetExpirationHeightFull(lastUpdatedHeight uint32, extended bool) uint32 {
	if extended {
		return lastUpdatedHeight + ExtendedClaimExpirationTime
	}
	if lastUpdatedHeight < ExtendedClaimExpirationForkHeight {
		return lastUpdatedHeight + OriginalClaimExpirationTime
	}
	return lastUpdatedHeight + ExtendedClaimExpirationTime
}

// EnsureHandle is a helper function to ensure that the db has a handle to the given column family.
func (db *ReadOnlyDBColumnFamily) EnsureHandle(prefix byte) (*grocksdb.ColumnFamilyHandle, error) {
	cfName := string(prefix)
	handle := db.Handles[cfName]
	if handle == nil {
		return nil, fmt.Errorf("%s handle not found", cfName)
	}
	return handle, nil
}

// GetBlockHash returns the block hash for the given height.
func (db *ReadOnlyDBColumnFamily) GetBlockHash(height uint32) ([]byte, error) {
	handle, err := db.EnsureHandle(prefixes.BlockHash)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewBlockHashKey(height)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, err
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	return rawValue, nil
}

func (db *ReadOnlyDBColumnFamily) GetBlockTXs(height uint32) ([]*chainhash.Hash, error) {
	handle, err := db.EnsureHandle(prefixes.BlockTXs)
	if err != nil {
		return nil, err
	}

	key := prefixes.BlockTxsKey{
		Prefix: []byte{prefixes.BlockTXs},
		Height: height,
	}
	slice, err := db.DB.GetCF(db.Opts, handle, key.PackKey())
	defer slice.Free()
	if err != nil {
		return nil, err
	}
	if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.BlockTxsValueUnpack(rawValue)
	return value.TxHashes, nil
}

func (db *ReadOnlyDBColumnFamily) GetTouchedHashXs(height uint32) ([][]byte, error) {
	handle, err := db.EnsureHandle(prefixes.TouchedHashX)
	if err != nil {
		return nil, err
	}

	key := prefixes.TouchedHashXKey{
		Prefix: []byte{prefixes.TouchedHashX},
		Height: height,
	}
	slice, err := db.DB.GetCF(db.Opts, handle, key.PackKey())
	defer slice.Free()
	if err != nil {
		return nil, err
	}
	if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.TouchedHashXValue{}
	value.UnpackValue(rawValue)
	return value.TouchedHashXs, nil
}

func (db *ReadOnlyDBColumnFamily) GetHeader(height uint32) ([]byte, error) {
	handle, err := db.EnsureHandle(prefixes.Header)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewHeaderKey(height)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, err
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	return rawValue, nil
}

func (db *ReadOnlyDBColumnFamily) GetHeaders(height uint32, count uint32) ([][112]byte, error) {
	handle, err := db.EnsureHandle(prefixes.Header)
	if err != nil {
		return nil, err
	}

	startKeyRaw := prefixes.NewHeaderKey(height).PackKey()
	endKeyRaw := prefixes.NewHeaderKey(height + count).PackKey()
	options := NewIterateOptions().WithDB(db).WithPrefix([]byte{prefixes.Header}).WithCfHandle(handle)
	options = options.WithIncludeKey(false).WithIncludeValue(true) //.WithIncludeStop(true)
	options = options.WithStart(startKeyRaw).WithStop(endKeyRaw)

	result := make([][112]byte, 0, count)
	for kv := range IterCF(db.DB, options) {
		h := [112]byte{}
		copy(h[:], kv.Value.(*prefixes.BlockHeaderValue).Header[:112])
		result = append(result, h)
	}

	return result, nil
}

func (db *ReadOnlyDBColumnFamily) GetBalance(hashX []byte) (uint64, uint64, error) {
	handle, err := db.EnsureHandle(prefixes.UTXO)
	if err != nil {
		return 0, 0, err
	}

	startKey := prefixes.UTXOKey{
		Prefix: []byte{prefixes.UTXO},
		HashX:  hashX,
		TxNum:  0,
		Nout:   0,
	}
	endKey := prefixes.UTXOKey{
		Prefix: []byte{prefixes.UTXO},
		HashX:  hashX,
		TxNum:  math.MaxUint32,
		Nout:   math.MaxUint16,
	}

	startKeyRaw := startKey.PackKey()
	endKeyRaw := endKey.PackKey()
	// Prefix and handle
	options := NewIterateOptions().WithDB(db).WithPrefix([]byte{prefixes.UTXO}).WithCfHandle(handle)
	// Start and stop bounds
	options = options.WithStart(startKeyRaw).WithStop(endKeyRaw).WithIncludeStop(true)
	// Don't include the key
	options = options.WithIncludeKey(false).WithIncludeValue(true)

	ch := IterCF(db.DB, options)
	var confirmed uint64 = 0
	var unconfirmed uint64 = 0 // TODO
	for kv := range ch {
		confirmed += kv.Value.(*prefixes.UTXOValue).Amount
	}

	return confirmed, unconfirmed, nil
}

type TXOInfo struct {
	TxHash *chainhash.Hash
	TxPos  uint16
	Height uint32
	Value  uint64
}

func (db *ReadOnlyDBColumnFamily) GetUnspent(hashX []byte) ([]TXOInfo, error) {
	startKey := &prefixes.UTXOKey{
		Prefix: []byte{prefixes.UTXO},
		HashX:  hashX,
		TxNum:  0,
		Nout:   0,
	}
	endKey := &prefixes.UTXOKey{
		Prefix: []byte{prefixes.UTXO},
		HashX:  hashX,
		TxNum:  math.MaxUint32,
		Nout:   math.MaxUint16,
	}
	selectedUTXO, err := db.selectFrom([]byte{prefixes.UTXO}, startKey, endKey)
	if err != nil {
		return nil, err
	}

	selectTxHashByTxNum := func(in []*prefixes.PrefixRowKV) ([]*IterOptions, error) {
		historyKey := in[0].Key.(*prefixes.UTXOKey)
		out := make([]*IterOptions, 0, 100)
		startKey := &prefixes.TxHashKey{
			Prefix: []byte{prefixes.TxHash},
			TxNum:  historyKey.TxNum,
		}
		endKey := &prefixes.TxHashKey{
			Prefix: []byte{prefixes.TxHash},
			TxNum:  historyKey.TxNum,
		}
		selectedTxHash, err := db.selectFrom([]byte{prefixes.TxHash}, startKey, endKey)
		if err != nil {
			return nil, err
		}
		out = append(out, selectedTxHash...)
		return out, nil
	}

	results := make([]TXOInfo, 0, 1000)
	for kvs := range innerJoin(db.DB, iterate(db.DB, selectedUTXO), selectTxHashByTxNum) {
		if err := checkForError(kvs); err != nil {
			return results, err
		}
		utxoKey := kvs[0].Key.(*prefixes.UTXOKey)
		utxoValue := kvs[0].Value.(*prefixes.UTXOValue)
		txhashValue := kvs[1].Value.(*prefixes.TxHashValue)
		results = append(results,
			TXOInfo{
				TxHash: txhashValue.TxHash,
				TxPos:  utxoKey.Nout,
				Height: stack.BisectRight(db.TxCounts, []uint32{utxoKey.TxNum})[0],
				Value:  utxoValue.Amount,
			},
		)
	}
	return results, nil
}

type TxInfo struct {
	TxHash *chainhash.Hash
	Height uint32
}

func (db *ReadOnlyDBColumnFamily) GetHistory(hashX []byte) ([]TxInfo, error) {
	startKey := &prefixes.HashXHistoryKey{
		Prefix: []byte{prefixes.HashXHistory},
		HashX:  hashX,
		Height: 0,
	}
	endKey := &prefixes.HashXHistoryKey{
		Prefix: []byte{prefixes.HashXHistory},
		HashX:  hashX,
		Height: math.MaxUint32,
	}
	selectedHistory, err := db.selectFrom([]byte{prefixes.HashXHistory}, startKey, endKey)
	if err != nil {
		return nil, err
	}

	selectTxHashByTxNums := func(in []*prefixes.PrefixRowKV) ([]*IterOptions, error) {
		historyValue := in[0].Value.(*prefixes.HashXHistoryValue)
		out := make([]*IterOptions, 0, 100)
		for _, txnum := range historyValue.TxNums {
			startKey := &prefixes.TxHashKey{
				Prefix: []byte{prefixes.TxHash},
				TxNum:  txnum,
			}
			endKey := &prefixes.TxHashKey{
				Prefix: []byte{prefixes.TxHash},
				TxNum:  txnum,
			}
			selectedTxHash, err := db.selectFrom([]byte{prefixes.TxHash}, startKey, endKey)
			if err != nil {
				return nil, err
			}
			out = append(out, selectedTxHash...)
		}
		return out, nil
	}

	results := make([]TxInfo, 0, 1000)
	for kvs := range innerJoin(db.DB, iterate(db.DB, selectedHistory), selectTxHashByTxNums) {
		if err := checkForError(kvs); err != nil {
			return results, err
		}
		historyKey := kvs[0].Key.(*prefixes.HashXHistoryKey)
		txHashValue := kvs[1].Value.(*prefixes.TxHashValue)
		results = append(results, TxInfo{
			TxHash: txHashValue.TxHash,
			Height: historyKey.Height,
		})
	}
	return results, nil
}

func (db *ReadOnlyDBColumnFamily) GetStatus(hashX []byte) ([]byte, error) {
	// Lookup in HashXMempoolStatus first.
	status, err := db.getMempoolStatus(hashX)
	if err == nil && status != nil {
		log.Debugf("(mempool) status(%#v) -> %#v", hashX, status)
		return status, err
	}

	// No indexed mempool status. Lookup in HashXStatus second.
	handle, err := db.EnsureHandle(prefixes.HashXStatus)
	if err != nil {
		return nil, err
	}
	key := &prefixes.HashXStatusKey{
		Prefix: []byte{prefixes.HashXStatus},
		HashX:  hashX,
	}
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err == nil && slice.Size() > 0 {
		rawValue := make([]byte, len(slice.Data()))
		copy(rawValue, slice.Data())
		value := prefixes.HashXStatusValue{}
		value.UnpackValue(rawValue)
		log.Debugf("status(%#v) -> %#v", hashX, value.Status)
		return value.Status, nil
	}

	// No indexed status. Fall back to enumerating HashXHistory.
	txs, err := db.GetHistory(hashX)
	if err != nil {
		return nil, err
	}

	if len(txs) == 0 {
		return []byte{}, err
	}

	hash := sha256.New()
	for _, tx := range txs {
		hash.Write([]byte(fmt.Sprintf("%s:%d:", tx.TxHash.String(), tx.Height)))
	}
	// TODO: Mempool history
	return hash.Sum(nil), err
}

func (db *ReadOnlyDBColumnFamily) getMempoolStatus(hashX []byte) ([]byte, error) {
	handle, err := db.EnsureHandle(prefixes.HashXMempoolStatus)
	if err != nil {
		return nil, err
	}

	key := &prefixes.HashXMempoolStatusKey{
		Prefix: []byte{prefixes.HashXMempoolStatus},
		HashX:  hashX,
	}
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.HashXMempoolStatusValue{}
	value.UnpackValue(rawValue)
	return value.Status, nil
}

// GetStreamsAndChannelRepostedByChannelHashes returns a map of streams and channel hashes that are reposted by the given channel hashes.
func (db *ReadOnlyDBColumnFamily) GetStreamsAndChannelRepostedByChannelHashes(reposterChannelHashes [][]byte) (map[string][]byte, map[string][]byte, error) {
	handle, err := db.EnsureHandle(prefixes.ChannelToClaim)
	if err != nil {
		return nil, nil, err
	}

	streams := make(map[string][]byte)
	channels := make(map[string][]byte)

	for _, reposterChannelHash := range reposterChannelHashes {
		key := prefixes.NewChannelToClaimKeyWHash(reposterChannelHash)
		rawKeyPrefix := key.PartialPack(1)
		options := NewIterateOptions().WithDB(db).WithCfHandle(handle).WithPrefix(rawKeyPrefix)
		options = options.WithIncludeKey(false).WithIncludeValue(true)
		ch := IterCF(db.DB, options)
		// for stream := range Iterate(db.DB, prefixes.ChannelToClaim, []byte{reposterChannelHash}, false) {
		for stream := range ch {
			value := stream.Value.(*prefixes.ChannelToClaimValue)
			repost, err := db.GetRepost(value.ClaimHash)
			if err != nil {
				return nil, nil, err
			}
			if repost != nil {
				txo, err := db.GetClaimTxo(repost)
				if err != nil {
					return nil, nil, err
				}
				if txo != nil {
					repostStr := hex.EncodeToString(repost)
					if normalName := txo.NormalizedName(); len(normalName) > 0 && normalName[0] == '@' {
						channels[repostStr] = reposterChannelHash
					} else {
						streams[repostStr] = reposterChannelHash
					}
				}
			}
		}
	}

	return streams, channels, nil
}

// GetClaimsInChannelCount returns the number of claims in the given channel.
func (db *ReadOnlyDBColumnFamily) GetClaimsInChannelCount(channelHash []byte) (uint32, error) {
	handle, err := db.EnsureHandle(prefixes.ChannelCount)
	if err != nil {
		return 0, err
	}

	key := prefixes.NewChannelCountKey(channelHash)
	rawKey := key.PackKey()

	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return 0, err
	} else if slice.Size() == 0 {
		return 0, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.ChannelCountValueUnpack(rawValue)

	return value.Count, nil
}

func (db *ReadOnlyDBColumnFamily) GetShortClaimIdUrl(name string, normalizedName string, claimHash []byte, rootTxNum uint32, rootPosition uint16) (string, error) {
	prefix := []byte{prefixes.ClaimShortIdPrefix}
	handle, err := db.EnsureHandle(prefixes.ClaimShortIdPrefix)
	if err != nil {
		return "", err
	}

	claimId := hex.EncodeToString(claimHash)
	claimIdLen := len(claimId)
	for prefixLen := 0; prefixLen < 10; prefixLen++ {
		var j int = prefixLen + 1
		if j > claimIdLen {
			j = claimIdLen
		}
		partialClaimId := claimId[:j]
		partialKey := prefixes.NewClaimShortIDKey(normalizedName, partialClaimId)
		log.Printf("partialKey: %#v\n", partialKey)
		keyPrefix := partialKey.PartialPack(2)
		// Prefix and handle
		options := NewIterateOptions().WithDB(db).WithPrefix(prefix).WithCfHandle(handle)
		// Start and stop bounds
		options = options.WithStart(keyPrefix).WithStop(keyPrefix)
		// Don't include the key
		options = options.WithIncludeValue(false)

		ch := IterCF(db.DB, options)
		row := <-ch
		if row == nil {
			continue
		}

		key := row.Key.(*prefixes.ClaimShortIDKey)
		if key.RootTxNum == rootTxNum && key.RootPosition == rootPosition {
			return fmt.Sprintf("%s#%s", name, key.PartialClaimId), nil
		}
	}
	return "", nil
}

func (db *ReadOnlyDBColumnFamily) GetRepost(claimHash []byte) ([]byte, error) {
	handle, err := db.EnsureHandle(prefixes.Repost)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewRepostKey(claimHash)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.RepostValueUnpack(rawValue)
	return value.RepostedClaimHash, nil
}

func (db *ReadOnlyDBColumnFamily) GetRepostedCount(claimHash []byte) (int, error) {
	handle, err := db.EnsureHandle(prefixes.RepostedCount)
	if err != nil {
		return 0, err
	}

	key := prefixes.RepostedCountKey{Prefix: []byte{prefixes.RepostedCount}, ClaimHash: claimHash}
	rawKey := key.PackKey()

	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return 0, err
	} else if slice.Size() == 0 {
		return 0, nil
	}

	value := prefixes.RepostedCountValue{}
	value.UnpackValue(slice.Data())
	return int(value.RepostedCount), nil
}

func (db *ReadOnlyDBColumnFamily) GetChannelForClaim(claimHash []byte, txNum uint32, position uint16) ([]byte, error) {
	handle, err := db.EnsureHandle(prefixes.ClaimToChannel)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewClaimToChannelKey(claimHash, txNum, position)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.ClaimToChannelValueUnpack(rawValue)
	return value.SigningHash, nil
}

func (db *ReadOnlyDBColumnFamily) GetActiveAmount(claimHash []byte, txoType uint8, height uint32) (uint64, error) {
	handle, err := db.EnsureHandle(prefixes.ActiveAmount)
	if err != nil {
		return 0, err
	}

	startKey := prefixes.NewActiveAmountKey(claimHash, txoType, 0)
	endKey := prefixes.NewActiveAmountKey(claimHash, txoType, height+1)

	startKeyRaw := startKey.PartialPack(3)
	endKeyRaw := endKey.PartialPack(3)
	// Prefix and handle
	options := NewIterateOptions().WithDB(db).WithPrefix([]byte{prefixes.ActiveAmount}).WithCfHandle(handle)
	// Start and stop bounds
	options = options.WithStart(startKeyRaw).WithStop(endKeyRaw)
	// Don't include the key
	options = options.WithIncludeKey(false).WithIncludeValue(true)

	ch := IterCF(db.DB, options)
	var sum uint64 = 0
	for kv := range ch {
		sum += kv.Value.(*prefixes.ActiveAmountValue).Amount
	}

	return sum, nil
}

func (db *ReadOnlyDBColumnFamily) GetEffectiveAmount(claimHash []byte, supportOnly bool) (uint64, error) {
	handle, err := db.EnsureHandle(prefixes.EffectiveAmount)
	if err != nil {
		return 0, err
	}

	key := prefixes.EffectiveAmountKey{Prefix: []byte{prefixes.EffectiveAmount}, ClaimHash: claimHash}
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return 0, err
	} else if slice.Size() == 0 {
		return 0, nil
	}

	value := prefixes.EffectiveAmountValue{}
	value.UnpackValue(slice.Data())
	var amount uint64
	if supportOnly {
		amount += value.ActivatedSupportSum
	} else {
		amount += value.ActivatedSum
	}
	return amount, nil
}

func (db *ReadOnlyDBColumnFamily) GetSupportAmount(claimHash []byte) (uint64, error) {
	handle, err := db.EnsureHandle(prefixes.SupportAmount)
	if err != nil {
		return 0, err
	}

	key := prefixes.NewSupportAmountKey(claimHash)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return 0, err
	} else if slice.Size() == 0 {
		return 0, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.SupportAmountValueUnpack(rawValue)
	return value.Amount, nil
}

func (db *ReadOnlyDBColumnFamily) GetTxHash(txNum uint32) ([]byte, error) {
	// TODO: caching
	handle, err := db.EnsureHandle(prefixes.TxHash)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewTxHashKey(txNum)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	}
	if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	return rawValue, nil
}

func (db *ReadOnlyDBColumnFamily) GetActivation(txNum uint32, postition uint16) (uint32, error) {
	return db.GetActivationFull(txNum, postition, false)
}

func (db *ReadOnlyDBColumnFamily) GetActivationFull(txNum uint32, postition uint16, isSupport bool) (uint32, error) {
	var typ uint8

	handle, err := db.EnsureHandle(prefixes.ActivatedClaimAndSupport)
	if err != nil {
		return 0, err
	}

	if isSupport {
		typ = prefixes.ActivatedSupportTXOType
	} else {
		typ = prefixes.ActivateClaimTXOType
	}

	key := prefixes.NewActivationKey(typ, txNum, postition)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return 0, err
	}
	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.ActivationValueUnpack(rawValue)
	// Does this need to explicitly return an int64, in case the uint32 overflows the max of an int?
	return value.Height, nil
}

func (db *ReadOnlyDBColumnFamily) GetClaimTxo(claim []byte) (*prefixes.ClaimToTXOValue, error) {
	return db.GetCachedClaimTxo(claim, false)
}

func (db *ReadOnlyDBColumnFamily) GetCachedClaimTxo(claim []byte, useCache bool) (*prefixes.ClaimToTXOValue, error) {
	// TODO: implement cache
	handle, err := db.EnsureHandle(prefixes.ClaimToTXO)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewClaimToTXOKey(claim)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	}
	if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.ClaimToTXOValueUnpack(rawValue)
	return value, nil
}

func (db *ReadOnlyDBColumnFamily) ControllingClaimIter() <-chan *prefixes.PrefixRowKV {
	handle, err := db.EnsureHandle(prefixes.ClaimTakeover)
	if err != nil {
		return nil
	}

	key := prefixes.NewClaimTakeoverKey("")
	var rawKeyPrefix []byte = nil
	rawKeyPrefix = key.PartialPack(0)
	options := NewIterateOptions().WithDB(db).WithCfHandle(handle).WithPrefix(rawKeyPrefix)
	options = options.WithIncludeValue(true) //.WithIncludeStop(true)
	ch := IterCF(db.DB, options)
	return ch
}

func (db *ReadOnlyDBColumnFamily) GetControllingClaim(name string) (*prefixes.ClaimTakeoverValue, error) {
	handle, err := db.EnsureHandle(prefixes.ClaimTakeover)
	if err != nil {
		return nil, err
	}

	log.Println(name)
	key := prefixes.NewClaimTakeoverKey(name)
	rawKey := key.PackKey()
	log.Println(hex.EncodeToString(rawKey))
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()

	if err != nil {
		return nil, err
	}
	if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.ClaimTakeoverValueUnpack(rawValue)
	return value, nil
}

func (db *ReadOnlyDBColumnFamily) FsGetClaimByHash(claimHash []byte) (*ResolveResult, error) {
	claim, err := db.GetCachedClaimTxo(claimHash, true)
	if err != nil {
		return nil, err
	}

	activation, err := db.GetActivation(claim.TxNum, claim.Position)
	if err != nil {
		return nil, err
	}

	log.Printf("%#v\n%#v\n%#v\n", claim, hex.EncodeToString(claimHash), activation)
	return PrepareResolveResult(
		db,
		claim.TxNum,
		claim.Position,
		claimHash,
		claim.Name,
		claim.RootTxNum,
		claim.RootPosition,
		activation,
		claim.ChannelSignatureIsValid,
	)
}

func (db *ReadOnlyDBColumnFamily) GetTx(txhash *chainhash.Hash) ([]byte, *wire.MsgTx, error) {
	// Lookup in MempoolTx first.
	raw, tx, err := db.getMempoolTx(txhash)
	if err == nil && raw != nil && tx != nil {
		return raw, tx, err
	}

	handle, err := db.EnsureHandle(prefixes.Tx)
	if err != nil {
		return nil, nil, err
	}

	key := prefixes.TxKey{Prefix: []byte{prefixes.Tx}, TxHash: txhash}
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, nil, err
	}
	if slice.Size() == 0 {
		return nil, nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.TxValue{}
	value.UnpackValue(rawValue)
	var msgTx wire.MsgTx
	err = msgTx.Deserialize(bytes.NewReader(value.RawTx))
	if err != nil {
		return nil, nil, err
	}
	return value.RawTx, &msgTx, nil
}

func (db *ReadOnlyDBColumnFamily) getMempoolTx(txhash *chainhash.Hash) ([]byte, *wire.MsgTx, error) {
	handle, err := db.EnsureHandle(prefixes.MempoolTx)
	if err != nil {
		return nil, nil, err
	}

	key := prefixes.MempoolTxKey{Prefix: []byte{prefixes.Tx}, TxHash: txhash}
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, nil, err
	}
	if slice.Size() == 0 {
		return nil, nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.MempoolTxValue{}
	value.UnpackValue(rawValue)
	var msgTx wire.MsgTx
	err = msgTx.Deserialize(bytes.NewReader(value.RawTx))
	if err != nil {
		return nil, nil, err
	}
	return value.RawTx, &msgTx, nil
}

func (db *ReadOnlyDBColumnFamily) GetTxCount(height uint32) (*prefixes.TxCountValue, error) {
	handle, err := db.EnsureHandle(prefixes.TxCount)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewTxCountKey(height)
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	}
	if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.TxCountValueUnpack(rawValue)
	return value, nil
}

func (db *ReadOnlyDBColumnFamily) GetTxHeight(txhash *chainhash.Hash) (uint32, error) {
	handle, err := db.EnsureHandle(prefixes.TxNum)
	if err != nil {
		return 0, err
	}

	key := prefixes.TxNumKey{Prefix: []byte{prefixes.TxNum}, TxHash: txhash}
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return 0, err
	}
	if slice.Size() == 0 {
		return 0, nil
	}

	// No slice copy needed. Value will be abandoned.
	value := prefixes.TxNumValueUnpack(slice.Data())
	height := stack.BisectRight(db.TxCounts, []uint32{value.TxNum})[0]
	return height, nil
}

type TxMerkle struct {
	TxHash *chainhash.Hash
	RawTx  []byte
	Height int
	Pos    uint32
	Merkle []*chainhash.Hash
}

// merklePath selects specific transactions by position within blockTxs.
// The resulting merkle path (aka merkle branch, or merkle) is a list of TX hashes
// which are in sibling relationship with TX nodes on the path to the root.
func merklePath(pos uint32, blockTxs, partial []*chainhash.Hash) []*chainhash.Hash {
	parent := func(p uint32) uint32 {
		return p >> 1
	}
	sibling := func(p uint32) uint32 {
		if p%2 == 0 {
			return p + 1
		} else {
			return p - 1
		}
	}
	p := parent(pos)
	if p == 0 {
		// No parent, path is complete.
		return partial
	}
	// Add sibling to partial path and proceed to parent TX.
	return merklePath(p, blockTxs, append(partial, blockTxs[sibling(pos)]))
}

func (db *ReadOnlyDBColumnFamily) GetTxMerkle(tx_hashes []chainhash.Hash) ([]TxMerkle, error) {

	selectedTxNum := make([]*IterOptions, 0, len(tx_hashes))
	for _, txhash := range tx_hashes {
		key := prefixes.TxNumKey{Prefix: []byte{prefixes.TxNum}, TxHash: &txhash}
		log.Debugf("%v", key)
		opt, err := db.selectFrom(key.Prefix, &key, &key)
		if err != nil {
			return nil, err
		}
		selectedTxNum = append(selectedTxNum, opt...)
	}

	selectTxByTxNum := func(in []*prefixes.PrefixRowKV) ([]*IterOptions, error) {
		txNumKey := in[0].Key.(*prefixes.TxNumKey)
		log.Debugf("%v", txNumKey.TxHash.String())
		out := make([]*IterOptions, 0, 100)
		startKey := &prefixes.TxKey{
			Prefix: []byte{prefixes.Tx},
			TxHash: txNumKey.TxHash,
		}
		endKey := &prefixes.TxKey{
			Prefix: []byte{prefixes.Tx},
			TxHash: txNumKey.TxHash,
		}
		selectedTx, err := db.selectFrom([]byte{prefixes.Tx}, startKey, endKey)
		if err != nil {
			return nil, err
		}
		out = append(out, selectedTx...)
		return out, nil
	}

	blockTxsCache := make(map[uint32][]*chainhash.Hash)
	results := make([]TxMerkle, 0, 500)
	for kvs := range innerJoin(db.DB, iterate(db.DB, selectedTxNum), selectTxByTxNum) {
		if err := checkForError(kvs); err != nil {
			return results, err
		}
		txNumKey, txNumVal := kvs[0].Key.(*prefixes.TxNumKey), kvs[0].Value.(*prefixes.TxNumValue)
		_, txVal := kvs[1].Key.(*prefixes.TxKey), kvs[1].Value.(*prefixes.TxValue)
		txHeight := stack.BisectRight(db.TxCounts, []uint32{txNumVal.TxNum})[0]
		txPos := txNumVal.TxNum - db.TxCounts.Get(txHeight-1)
		// We need all the TX hashes in order to select out the relevant ones.
		if _, ok := blockTxsCache[txHeight]; !ok {
			txs, err := db.GetBlockTXs(txHeight)
			if err != nil {
				return results, err
			}
			blockTxsCache[txHeight] = txs
		}
		blockTxs := blockTxsCache[txHeight]
		results = append(results, TxMerkle{
			TxHash: txNumKey.TxHash,
			RawTx:  txVal.RawTx,
			Height: int(txHeight),
			Pos:    txPos,
			Merkle: merklePath(txPos, blockTxs, []*chainhash.Hash{}),
		})
	}
	return results, nil
}

func (db *ReadOnlyDBColumnFamily) GetClaimByID(claimID string) ([]*ExpandedResolveResult, []*ExpandedResolveResult, error) {
	rows := make([]*ExpandedResolveResult, 0)
	extras := make([]*ExpandedResolveResult, 0)
	claimHash, err := hex.DecodeString(claimID)
	if err != nil {
		return nil, nil, err
	}

	stream, err := db.FsGetClaimByHash(claimHash)
	if err != nil {
		return nil, nil, err
	}
	var res = NewExpandedResolveResult()
	res.Stream = &optionalResolveResultOrError{res: stream}
	rows = append(rows, res)

	if stream != nil && stream.ChannelHash != nil {
		channel, err := db.FsGetClaimByHash(stream.ChannelHash)
		if err != nil {
			return nil, nil, err
		}
		var res = NewExpandedResolveResult()
		res.Channel = &optionalResolveResultOrError{res: channel}
		extras = append(extras, res)
	}

	if stream != nil && stream.RepostedClaimHash != nil {
		repost, err := db.FsGetClaimByHash(stream.RepostedClaimHash)
		if err != nil {
			return nil, nil, err
		}
		var res = NewExpandedResolveResult()
		res.Repost = &optionalResolveResultOrError{res: repost}
		extras = append(extras, res)
	}

	return rows, extras, nil
}

func (db *ReadOnlyDBColumnFamily) GetDBState() (*prefixes.DBStateValue, error) {
	handle, err := db.EnsureHandle(prefixes.DBState)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewDBStateKey()
	rawKey := key.PackKey()
	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.DBStateValueUnpack(rawValue)
	return value, nil
}

func (db *ReadOnlyDBColumnFamily) BidOrderNameIter(normalizedName string) <-chan *prefixes.PrefixRowKV {
	handle, err := db.EnsureHandle(prefixes.BidOrder)
	if err != nil {
		return nil
	}

	key := prefixes.NewBidOrderKey(normalizedName)
	var rawKeyPrefix []byte = nil
	rawKeyPrefix = key.PartialPack(1)
	options := NewIterateOptions().WithDB(db).WithCfHandle(handle).WithPrefix(rawKeyPrefix)
	options = options.WithIncludeValue(true) //.WithIncludeStop(true)
	ch := IterCF(db.DB, options)
	return ch
}

func (db *ReadOnlyDBColumnFamily) ClaimShortIdIter(normalizedName string, claimId string) <-chan *prefixes.PrefixRowKV {
	handle, err := db.EnsureHandle(prefixes.ClaimShortIdPrefix)
	if err != nil {
		return nil
	}
	key := prefixes.NewClaimShortIDKey(normalizedName, claimId)
	var rawKeyPrefix []byte = nil
	if claimId != "" {
		rawKeyPrefix = key.PartialPack(2)
	} else {
		rawKeyPrefix = key.PartialPack(1)
	}
	options := NewIterateOptions().WithDB(db).WithCfHandle(handle).WithPrefix(rawKeyPrefix)
	options = options.WithIncludeValue(true) //.WithIncludeStop(true)
	ch := IterCF(db.DB, options)
	return ch
}

func (db *ReadOnlyDBColumnFamily) GetCachedClaimHash(txNum uint32, position uint16) (*prefixes.TXOToClaimValue, error) {
	// TODO: implement cache
	handle, err := db.EnsureHandle(prefixes.TXOToClaim)
	if err != nil {
		return nil, err
	}

	key := prefixes.NewTXOToClaimKey(txNum, position)
	rawKey := key.PackKey()

	slice, err := db.DB.GetCF(db.Opts, handle, rawKey)
	defer slice.Free()
	if err != nil {
		return nil, err
	} else if slice.Size() == 0 {
		return nil, nil
	}

	rawValue := make([]byte, len(slice.Data()))
	copy(rawValue, slice.Data())
	value := prefixes.TXOToClaimValueUnpack(rawValue)
	return value, nil
}

// GetBlockerHash get the hash of the blocker or filterer of the claim.
// TODO: this currently converts the byte arrays to strings, which is not
// very efficient. Might want to figure out a better way to do this.
func (db *ReadOnlyDBColumnFamily) GetBlockerHash(claimHash, repostedClaimHash, channelHash []byte) ([]byte, []byte, error) {
	claimHashStr := string(claimHash)
	respostedClaimHashStr := string(repostedClaimHash)
	channelHashStr := string(channelHash)

	var blockedHash []byte = nil
	var filteredHash []byte = nil

	blockedHash = db.BlockedStreams[claimHashStr]
	if blockedHash == nil {
		blockedHash = db.BlockedStreams[respostedClaimHashStr]
	}
	if blockedHash == nil {
		blockedHash = db.BlockedChannels[claimHashStr]
	}
	if blockedHash == nil {
		blockedHash = db.BlockedChannels[respostedClaimHashStr]
	}
	if blockedHash == nil {
		blockedHash = db.BlockedChannels[channelHashStr]
	}

	filteredHash = db.FilteredStreams[claimHashStr]
	if filteredHash == nil {
		filteredHash = db.FilteredStreams[respostedClaimHashStr]
	}
	if filteredHash == nil {
		filteredHash = db.FilteredChannels[claimHashStr]
	}
	if filteredHash == nil {
		filteredHash = db.FilteredChannels[respostedClaimHashStr]
	}
	if filteredHash == nil {
		filteredHash = db.FilteredChannels[channelHashStr]
	}

	return blockedHash, filteredHash, nil
}