package services

import (
	"context"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"math/big"
	"strings"

	"github.com/coinbase/rosetta-sdk-go/server"
	"github.com/coinbase/rosetta-sdk-go/types"
	ethcommon "github.com/ethereum/go-ethereum/common"

	"github.com/harmony-one/harmony/core"
	"github.com/harmony-one/harmony/core/rawdb"
	hmytypes "github.com/harmony-one/harmony/core/types"
	"github.com/harmony-one/harmony/crypto/bls"
	"github.com/harmony-one/harmony/hmy"
	internalCommon "github.com/harmony-one/harmony/internal/common"
	nodeconfig "github.com/harmony-one/harmony/internal/configs/node"
	shardingconfig "github.com/harmony-one/harmony/internal/configs/sharding"
	"github.com/harmony-one/harmony/internal/utils"
	"github.com/harmony-one/harmony/rosetta/common"
	"github.com/harmony-one/harmony/rpc"
	rpcV2 "github.com/harmony-one/harmony/rpc/v2"
	"github.com/harmony-one/harmony/shard"
	"github.com/harmony-one/harmony/staking"
	stakingNetwork "github.com/harmony-one/harmony/staking/network"
	stakingTypes "github.com/harmony-one/harmony/staking/types"
)

// BlockAPI implements the server.BlockAPIServicer interface.
type BlockAPI struct {
	hmy *hmy.Harmony
}

// NewBlockAPI creates a new instance of a BlockAPI.
func NewBlockAPI(hmy *hmy.Harmony) server.BlockAPIServicer {
	return &BlockAPI{
		hmy: hmy,
	}
}

// Block implements the /block endpoint
func (s *BlockAPI) Block(
	ctx context.Context, request *types.BlockRequest,
) (response *types.BlockResponse, rosettaError *types.Error) {
	if err := assertValidNetworkIdentifier(request.NetworkIdentifier, s.hmy.ShardID); err != nil {
		return nil, err
	}

	var blk *hmytypes.Block
	var currBlockID, prevBlockID *types.BlockIdentifier
	if blk, rosettaError = s.getBlock(ctx, request.BlockIdentifier); rosettaError != nil {
		return nil, rosettaError
	}

	// Format genesis block if it is requested.
	if blk.Number().Uint64() == 0 {
		return s.genesisBlock(ctx, request, blk)
	}

	currBlockID = &types.BlockIdentifier{
		Index: blk.Number().Int64(),
		Hash:  blk.Hash().String(),
	}
	prevBlock, err := s.hmy.BlockByNumber(ctx, rpc.BlockNumber(blk.Number().Int64()-1).EthBlockNumber())
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	prevBlockID = &types.BlockIdentifier{
		Index: prevBlock.Number().Int64(),
		Hash:  prevBlock.Hash().String(),
	}

	// Report undelegation payouts as transactions to fit API.
	// Report all transactions here since all undelegation payout amounts are known after fetching payouts.
	transactions, rosettaError := s.getAllUndelegationPayoutTransactions(ctx, blk)
	if rosettaError != nil {
		return nil, rosettaError
	}

	responseBlock := &types.Block{
		BlockIdentifier:       currBlockID,
		ParentBlockIdentifier: prevBlockID,
		Timestamp:             blk.Time().Int64() * 1e3, // Timestamp must be in ms.
		Transactions:          transactions,
	}

	otherTransactions := []*types.TransactionIdentifier{}
	for _, tx := range blk.Transactions() {
		otherTransactions = append(otherTransactions, &types.TransactionIdentifier{
			Hash: tx.Hash().String(),
		})
	}
	for _, tx := range blk.StakingTransactions() {
		otherTransactions = append(otherTransactions, &types.TransactionIdentifier{
			Hash: tx.Hash().String(),
		})
	}
	// Report cross-shard transaction payouts.
	for _, cxReceipts := range blk.IncomingReceipts() {
		// Report cross-shard transaction payouts.
		for _, cxReceipt := range cxReceipts.Receipts {
			otherTransactions = append(otherTransactions, &types.TransactionIdentifier{
				Hash: cxReceipt.TxHash.String(),
			})
		}
	}
	// Report pre-staking era block rewards as transactions to fit API.
	if !s.hmy.IsStakingEpoch(blk.Epoch()) {
		preStakingRewardTxIDs, rosettaError := s.getAllPreStakingRewardTransactionIdentifiers(ctx, blk)
		if rosettaError != nil {
			return nil, rosettaError
		}
		otherTransactions = append(otherTransactions, preStakingRewardTxIDs...)
	}

	return &types.BlockResponse{
		Block:             responseBlock,
		OtherTransactions: otherTransactions,
	}, nil
}

// genesisBlock is a special handler for the genesis block.
func (s *BlockAPI) genesisBlock(
	ctx context.Context, request *types.BlockRequest, blk *hmytypes.Block,
) (response *types.BlockResponse, rosettaError *types.Error) {
	var currBlockID, prevBlockID *types.BlockIdentifier
	currBlockID = &types.BlockIdentifier{
		Index: blk.Number().Int64(),
		Hash:  blk.Hash().String(),
	}
	prevBlockID = currBlockID

	responseBlock := &types.Block{
		BlockIdentifier:       currBlockID,
		ParentBlockIdentifier: prevBlockID,
		Timestamp:             blk.Time().Int64() * 1e3, // Timestamp must be in ms.
		Transactions:          []*types.Transaction{},   // Do not return tx details as it is optional.
	}

	otherTransactions := []*types.TransactionIdentifier{}
	// Report initial genesis funds as transactions to fit API.
	for _, tx := range getPseudoTransactionForGenesis(getGenesisSpec(blk.ShardID())) {
		if tx.To() == nil {
			return nil, common.NewError(common.CatchAllError, nil)
		}
		otherTransactions = append(
			otherTransactions, getSpecialCaseTransactionIdentifier(blk.Hash(), *tx.To(), SpecialGenesisTxID),
		)
	}

	return &types.BlockResponse{
		Block:             responseBlock,
		OtherTransactions: otherTransactions,
	}, nil
}

// getAllPreStakingRewardTransactionIdentifiers is only used for the /block endpoint
func (s *BlockAPI) getAllPreStakingRewardTransactionIdentifiers(
	ctx context.Context, blk *hmytypes.Block,
) ([]*types.TransactionIdentifier, *types.Error) {
	txIDs := []*types.TransactionIdentifier{}
	blockSigInfo, rosettaError := s.getBlockSignerInfo(ctx, blk)
	if rosettaError != nil {
		return nil, rosettaError
	}
	for acc, signedBlsKeys := range blockSigInfo.signers {
		if len(signedBlsKeys) > 0 {
			txIDs = append(txIDs, getSpecialCaseTransactionIdentifier(blk.Hash(), acc, SpecialPreStakingRewardTxID))
		}
	}
	return txIDs, nil
}

// isCommitteeSelectionBlock ..
func (s *BlockAPI) isCommitteeSelectionBlock(blk *hmytypes.Block) bool {
	isBeaconChain := blk.ShardID() == shard.BeaconChainShardID
	isNewEpoch := len(blk.Header().ShardState()) > 0
	inPreStakingEra := s.hmy.IsPreStakingEpoch(blk.Epoch())
	return isBeaconChain && isNewEpoch && inPreStakingEra
}

// getAllUndelegationPayoutTransactions is only used for the /block endpoint
func (s *BlockAPI) getAllUndelegationPayoutTransactions(
	ctx context.Context, blk *hmytypes.Block,
) ([]*types.Transaction, *types.Error) {
	if !s.isCommitteeSelectionBlock(blk) {
		return []*types.Transaction{}, nil
	}

	delegatorPayouts, err := s.hmy.GetUndelegationPayouts(ctx, blk.Epoch())
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	transactions := []*types.Transaction{}
	for delegator, payout := range delegatorPayouts {
		accID, rosettaError := newAccountIdentifier(delegator)
		if rosettaError != nil {
			return nil, rosettaError
		}
		transactions = append(transactions, &types.Transaction{
			TransactionIdentifier: getSpecialCaseTransactionIdentifier(
				blk.Hash(), delegator, SpecialUndelegationPayoutTxID,
			),
			Operations: []*types.Operation{
				{
					OperationIdentifier: &types.OperationIdentifier{
						Index: 0, // There is no gas expenditure for undelegation payout
					},
					Type:    common.UndelegationPayoutOperation,
					Status:  common.SuccessOperationStatus.Status,
					Account: accID,
					Amount: &types.Amount{
						Value:    fmt.Sprintf("%v", payout),
						Currency: &common.Currency,
					},
				},
			},
		})
	}
	return transactions, nil
}

// getBlockSignerInfo fetches the block signer information for any non-genesis block
func (s *BlockAPI) getBlockSignerInfo(
	ctx context.Context, blk *hmytypes.Block,
) (*blockSignerInfo, *types.Error) {
	slotList, mask, err := s.hmy.GetBlockSigners(
		ctx, rpc.BlockNumber(blk.Number().Uint64()).EthBlockNumber(),
	)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	totalSigners := uint(0)
	sigInfos := map[ethcommon.Address][]bls.SerializedPublicKey{}
	for _, slot := range slotList {
		if _, ok := sigInfos[slot.EcdsaAddress]; !ok {
			sigInfos[slot.EcdsaAddress] = []bls.SerializedPublicKey{}
		}
		if ok, err := mask.KeyEnabled(slot.BLSPublicKey); ok && err == nil {
			sigInfos[slot.EcdsaAddress] = append(sigInfos[slot.EcdsaAddress], slot.BLSPublicKey)
			totalSigners++
		}
	}
	return &blockSignerInfo{
		signers:         sigInfos,
		totalKeysSigned: totalSigners,
		mask:            mask,
		blockHash:       blk.Hash(),
	}, nil
}

// BlockTransaction implements the /block/transaction endpoint
func (s *BlockAPI) BlockTransaction(
	ctx context.Context, request *types.BlockTransactionRequest,
) (*types.BlockTransactionResponse, *types.Error) {
	if err := assertValidNetworkIdentifier(request.NetworkIdentifier, s.hmy.ShardID); err != nil {
		return nil, err
	}

	// Format genesis block transaction request
	if request.BlockIdentifier.Index == 0 {
		return s.genesisBlockTransaction(ctx, request)
	}

	blockHash := ethcommon.HexToHash(request.BlockIdentifier.Hash)
	txHash := ethcommon.HexToHash(request.TransactionIdentifier.Hash)
	txInfo, rosettaError := s.getTransactionInfo(ctx, blockHash, txHash)
	if rosettaError != nil {
		// If no transaction info is found, check for special case transactions.
		response, rosettaError2 := s.specialBlockTransaction(ctx, request)
		if rosettaError2 != nil && rosettaError2.Code != common.TransactionNotFoundError.Code {
			return nil, common.NewError(common.TransactionNotFoundError, map[string]interface{}{
				"from_error": rosettaError2,
			})
		}
		return response, rosettaError2
	}

	var transaction *types.Transaction
	if txInfo.tx != nil && txInfo.receipt != nil {
		transaction, rosettaError = formatTransaction(txInfo.tx, txInfo.receipt)
		if rosettaError != nil {
			return nil, rosettaError
		}
	} else if txInfo.cxReceipt != nil {
		transaction, rosettaError = formatCrossShardReceiverTransaction(txInfo.cxReceipt)
		if rosettaError != nil {
			return nil, rosettaError
		}
	} else {
		return nil, &common.TransactionNotFoundError
	}
	return &types.BlockTransactionResponse{Transaction: transaction}, nil
}

// genesisBlockTransaction is a special handler for genesis block transactions
func (s *BlockAPI) genesisBlockTransaction(
	ctx context.Context, request *types.BlockTransactionRequest,
) (response *types.BlockTransactionResponse, rosettaError *types.Error) {
	genesisBlock, err := s.hmy.BlockByNumber(ctx, rpc.BlockNumber(0).EthBlockNumber())
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	blkHash, address, rosettaError := unpackSpecialCaseTransactionIdentifier(
		request.TransactionIdentifier, SpecialGenesisTxID,
	)
	if rosettaError != nil {
		return nil, rosettaError
	}
	if blkHash.String() != genesisBlock.Hash().String() {
		return nil, &common.TransactionNotFoundError
	}
	txs, rosettaError := formatGenesisTransaction(request.TransactionIdentifier, address, s.hmy.ShardID)
	if rosettaError != nil {
		return nil, rosettaError
	}
	return &types.BlockTransactionResponse{Transaction: txs}, nil
}

// specialBlockTransaction is a formatter for special, non-genesis, transactions
func (s *BlockAPI) specialBlockTransaction(
	ctx context.Context, request *types.BlockTransactionRequest,
) (*types.BlockTransactionResponse, *types.Error) {
	// If no transaction info is found, check for special case transactions.
	blk, rosettaError := s.getBlock(ctx, &types.PartialBlockIdentifier{Index: &request.BlockIdentifier.Index})
	if rosettaError != nil {
		return nil, rosettaError
	}
	if s.isCommitteeSelectionBlock(blk) {
		// Note that undelegation payout MUST be checked before reporting error in pre-staking & staking era.
		response, rosettaError := s.undelegationPayoutBlockTransaction(ctx, request.TransactionIdentifier, blk)
		if rosettaError != nil && !s.hmy.IsStakingEpoch(blk.Epoch()) && s.hmy.IsPreStakingEpoch(blk.Epoch()) {
			// Handle edge case special transaction for pre-staking era
			return s.preStakingRewardBlockTransaction(ctx, request.TransactionIdentifier, blk)
		}
		return response, rosettaError
	}
	if !s.hmy.IsStakingEpoch(blk.Epoch()) {
		return s.preStakingRewardBlockTransaction(ctx, request.TransactionIdentifier, blk)
	}
	return nil, &common.TransactionNotFoundError
}

// preStakingRewardBlockTransaction is a special handler for pre-staking era
func (s *BlockAPI) preStakingRewardBlockTransaction(
	ctx context.Context, txID *types.TransactionIdentifier, blk *hmytypes.Block,
) (*types.BlockTransactionResponse, *types.Error) {
	blkHash, address, rosettaError := unpackSpecialCaseTransactionIdentifier(txID, SpecialPreStakingRewardTxID)
	if rosettaError != nil {
		return nil, rosettaError
	}
	if blkHash.String() != blk.Hash().String() {
		return nil, common.NewError(common.SanityCheckError, map[string]interface{}{
			"message": fmt.Sprintf(
				"block hash %v != requested block hash %v in tx ID", blkHash.String(), blk.Hash().String(),
			),
		})
	}
	blockSignerInfo, rosettaError := s.getBlockSignerInfo(ctx, blk)
	if rosettaError != nil {
		return nil, rosettaError
	}
	transactions, rosettaError := formatPreStakingRewardTransaction(txID, blockSignerInfo, address)
	if rosettaError != nil {
		return nil, rosettaError
	}
	return &types.BlockTransactionResponse{Transaction: transactions}, nil
}

// undelegationPayoutBlockTransaction is a special handler for undelegation payout transactions
func (s *BlockAPI) undelegationPayoutBlockTransaction(
	ctx context.Context, txID *types.TransactionIdentifier, blk *hmytypes.Block,
) (*types.BlockTransactionResponse, *types.Error) {
	blkHash, address, rosettaError := unpackSpecialCaseTransactionIdentifier(txID, SpecialUndelegationPayoutTxID)
	if rosettaError != nil {
		return nil, rosettaError
	}
	if blkHash.String() != blk.Hash().String() {
		return nil, common.NewError(common.SanityCheckError, map[string]interface{}{
			"message": fmt.Sprintf(
				"block hash %v != requested block hash %v in tx ID", blkHash.String(), blk.Hash().String(),
			),
		})
	}

	delegatorPayouts, err := s.hmy.GetUndelegationPayouts(ctx, blk.Epoch())
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	transactions, rosettaError := formatUndelegationPayoutTransaction(txID, delegatorPayouts, address)
	if rosettaError != nil {
		return nil, rosettaError
	}
	return &types.BlockTransactionResponse{Transaction: transactions}, nil
}

// getBlock ..
func (s *BlockAPI) getBlock(
	ctx context.Context, request *types.PartialBlockIdentifier,
) (blk *hmytypes.Block, rosettaError *types.Error) {
	var err error
	if request.Hash != nil {
		requestBlockHash := ethcommon.HexToHash(*request.Hash)
		blk, err = s.hmy.GetBlock(ctx, requestBlockHash)
	} else if request.Index != nil {
		blk, err = s.hmy.BlockByNumber(ctx, rpc.BlockNumber(*request.Index).EthBlockNumber())
	} else {
		return nil, &common.BlockNotFoundError
	}
	if err != nil {
		return nil, common.NewError(common.BlockNotFoundError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	if blk == nil {
		return nil, &common.BlockNotFoundError
	}
	return blk, nil
}

// transactionInfo stores all related information for any transaction on the Harmony chain
// Note that some elements can be nil if not applicable
type transactionInfo struct {
	tx        hmytypes.PoolTransaction
	txIndex   uint64
	receipt   *hmytypes.Receipt
	cxReceipt *hmytypes.CXReceipt
}

// getTransactionInfo given the block hash and transaction hash
func (s *BlockAPI) getTransactionInfo(
	ctx context.Context, blockHash, txHash ethcommon.Hash,
) (txInfo *transactionInfo, rosettaError *types.Error) {
	// Look for all of the possible transactions
	var index uint64
	var plainTx *hmytypes.Transaction
	var stakingTx *stakingTypes.StakingTransaction
	plainTx, _, _, index = rawdb.ReadTransaction(s.hmy.ChainDb(), txHash)
	if plainTx == nil {
		stakingTx, _, _, index = rawdb.ReadStakingTransaction(s.hmy.ChainDb(), txHash)
	}
	cxReceipt, _, _, _ := rawdb.ReadCXReceipt(s.hmy.ChainDb(), txHash)

	if plainTx == nil && stakingTx == nil && cxReceipt == nil {
		return nil, &common.TransactionNotFoundError
	}

	var receipt *hmytypes.Receipt
	receipts, err := s.hmy.GetReceipts(ctx, blockHash)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	if int(index) < len(receipts) {
		receipt = receipts[index]
	}

	// Use pool transaction for concise formatting
	var tx hmytypes.PoolTransaction
	if stakingTx != nil {
		tx = stakingTx
	} else if plainTx != nil {
		tx = plainTx
	}

	return &transactionInfo{
		tx:        tx,
		txIndex:   index,
		receipt:   receipt,
		cxReceipt: cxReceipt,
	}, nil
}

func (s *BlockAPI) getTransactionReceiptFromIndex(
	ctx context.Context, blockHash ethcommon.Hash, index uint64,
) (*hmytypes.Receipt, *types.Error) {
	receipts, err := s.hmy.GetReceipts(ctx, blockHash)
	if err != nil || len(receipts) <= int(index) {
		message := fmt.Sprintf("Transasction receipt not found")
		if err != nil {
			message = fmt.Sprintf("Transasction receipt not found: %v", err.Error())
		}
		return nil, common.NewError(common.ReceiptNotFoundError, map[string]interface{}{
			"message": message,
		})
	}
	return receipts[index], nil
}

// getPseudoTransactionForGenesis to create unsigned transaction that contain genesis funds.
// Note that this is for internal usage only. Genesis funds are not transactions.
func getPseudoTransactionForGenesis(spec *core.Genesis) []*hmytypes.Transaction {
	txs := []*hmytypes.Transaction{}
	for acc, bal := range spec.Alloc {
		txs = append(txs, hmytypes.NewTransaction(
			0, acc, spec.ShardID, bal.Balance, 0, big.NewInt(0), spec.ExtraData,
		))
	}
	return txs
}

// SpecialTransactionSuffix ..
type SpecialTransactionSuffix uint

// Special transaction suffixes that are specific to the rosetta package
const (
	SpecialGenesisTxID SpecialTransactionSuffix = iota
	SpecialPreStakingRewardTxID
	SpecialUndelegationPayoutTxID
)

// String ..
func (s SpecialTransactionSuffix) String() string {
	return [...]string{"genesis", "reward", "undelegation"}[s]
}

// getSpecialCaseTransactionIdentifier fetches 'transaction identifiers' for a given block-hash and suffix.
// Special cases include genesis transactions, pre-staking era block rewards, and undelegation payouts.
// Must include block hash to guarantee uniqueness of tx identifiers.
func getSpecialCaseTransactionIdentifier(
	blockHash ethcommon.Hash, address ethcommon.Address, suffix SpecialTransactionSuffix,
) *types.TransactionIdentifier {
	return &types.TransactionIdentifier{
		Hash: fmt.Sprintf("%v_%v_%v",
			blockHash.String(), internalCommon.MustAddressToBech32(address), suffix.String(),
		),
	}
}

const (
	blockHashStrLen = 64
	b32AddrStrLen   = 42
)

// unpackSpecialCaseTransactionIdentifier returns the suffix & blockHash if the txID is formatted correctly.
func unpackSpecialCaseTransactionIdentifier(
	txID *types.TransactionIdentifier, expectedSuffix SpecialTransactionSuffix,
) (ethcommon.Hash, ethcommon.Address, *types.Error) {
	hash := txID.Hash
	hash = strings.TrimPrefix(hash, "0x")
	hash = strings.TrimPrefix(hash, "0X")
	minCharCount := blockHashStrLen + b32AddrStrLen + 2
	if len(hash) < minCharCount || string(hash[blockHashStrLen]) != "_" ||
		string(hash[minCharCount-1]) != "_" || expectedSuffix.String() != hash[minCharCount:] {
		return ethcommon.Hash{}, ethcommon.Address{}, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": "unknown special case transaction ID format",
		})
	}
	blkHash := ethcommon.HexToHash(hash[:blockHashStrLen])
	addr := internalCommon.MustBech32ToAddress(hash[blockHashStrLen+1 : minCharCount-1])
	return blkHash, addr, nil
}

// blockSignerInfo contains all of the block singing information
type blockSignerInfo struct {
	// signers is a map of addresses in the signers for the block to
	// all of the serialized BLS keys that signed said block.
	signers map[ethcommon.Address][]bls.SerializedPublicKey
	// totalKeysSigned is the total number of bls keys that signed the block.
	totalKeysSigned uint
	// mask is the bitmap mask for the block.
	mask      *bls.Mask
	blockHash ethcommon.Hash
}

// TransactionMetadata ..
type TransactionMetadata struct {
	// CrossShardIdentifier is the transaction identifier on the from/source shard
	CrossShardIdentifier *types.TransactionIdentifier `json:"cross_shard_transaction_identifier,omitempty"`
	ToShardID            *uint32                      `json:"to_shard,omitempty"`
	FromShardID          *uint32                      `json:"from_shard,omitempty"`
	Data                 *string                      `json:"data,omitempty"`
	Logs                 []*hmytypes.Log              `json:"logs,omitempty"`
}

// UnmarshalFromInterface ..
func (t *TransactionMetadata) UnmarshalFromInterface(metaData interface{}) error {
	var args TransactionMetadata
	dat, err := json.Marshal(metaData)
	if err != nil {
		return err
	}
	if err := json.Unmarshal(dat, &args); err != nil {
		return err
	}
	*t = args
	return nil
}

// formatCrossShardReceiverTransaction for cross-shard payouts on destination shard
func formatCrossShardReceiverTransaction(
	cxReceipt *hmytypes.CXReceipt,
) (txs *types.Transaction, rosettaError *types.Error) {
	ctxID := &types.TransactionIdentifier{Hash: cxReceipt.TxHash.String()}
	senderAccountID, rosettaError := newAccountIdentifier(cxReceipt.From)
	if rosettaError != nil {
		return nil, rosettaError
	}
	receiverAccountID, rosettaError := newAccountIdentifier(*cxReceipt.To)
	if rosettaError != nil {
		return nil, rosettaError
	}
	metadata, err := types.MarshalMap(TransactionMetadata{
		CrossShardIdentifier: ctxID,
		ToShardID:            &cxReceipt.ToShardID,
		FromShardID:          &cxReceipt.ShardID,
	})
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	opMetadata, err := types.MarshalMap(common.CrossShardTransactionOperationMetadata{
		From: senderAccountID,
		To:   receiverAccountID,
	})
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	return &types.Transaction{
		TransactionIdentifier: ctxID,
		Metadata:              metadata,
		Operations: []*types.Operation{
			{
				OperationIdentifier: &types.OperationIdentifier{
					Index: 0, // There is no gas expenditure for cross-shard transaction payout
				},
				Type:    common.CrossShardTransferOperation,
				Status:  common.SuccessOperationStatus.Status,
				Account: receiverAccountID,
				Amount: &types.Amount{
					Value:    fmt.Sprintf("%v", cxReceipt.Amount),
					Currency: &common.Currency,
				},
				Metadata: opMetadata,
			},
		},
	}, nil
}

// formatGenesisTransaction for genesis block's initial balances
func formatGenesisTransaction(
	txID *types.TransactionIdentifier, targetAddr ethcommon.Address, shardID uint32,
) (fmtTx *types.Transaction, rosettaError *types.Error) {
	var b32Addr string
	targetB32Addr := internalCommon.MustAddressToBech32(targetAddr)
	for _, tx := range getPseudoTransactionForGenesis(getGenesisSpec(shardID)) {
		if tx.To() == nil {
			return nil, common.NewError(common.CatchAllError, nil)
		}
		b32Addr = internalCommon.MustAddressToBech32(*tx.To())
		if targetB32Addr == b32Addr {
			accID, rosettaError := newAccountIdentifier(*tx.To())
			if rosettaError != nil {
				return nil, rosettaError
			}
			return &types.Transaction{
				TransactionIdentifier: txID,
				Operations: []*types.Operation{
					{
						OperationIdentifier: &types.OperationIdentifier{
							Index: 0,
						},
						Type:    common.GenesisFundsOperation,
						Status:  common.SuccessOperationStatus.Status,
						Account: accID,
						Amount: &types.Amount{
							Value:    fmt.Sprintf("%v", tx.Value()),
							Currency: &common.Currency,
						},
					},
				},
			}, nil
		}
	}
	return nil, &common.TransactionNotFoundError
}

// formatPreStakingRewardTransaction for block rewards in pre-staking era for a given Bech-32 address.
func formatPreStakingRewardTransaction(
	txID *types.TransactionIdentifier, blockSigInfo *blockSignerInfo, address ethcommon.Address,
) (*types.Transaction, *types.Error) {
	signatures, ok := blockSigInfo.signers[address]
	if !ok || len(signatures) == 0 {
		return nil, &common.TransactionNotFoundError
	}
	accID, rosettaError := newAccountIdentifier(address)
	if rosettaError != nil {
		return nil, rosettaError
	}

	// Calculate rewards exactly like `AccumulateRewardsAndCountSigs` but short circuit when possible.
	var rewardsForThisBlock *big.Int
	i := 0
	last := big.NewInt(0)
	count := big.NewInt(int64(blockSigInfo.totalKeysSigned))
	for sigAddr, keys := range blockSigInfo.signers {
		rewardsForThisAddr := big.NewInt(0)
		for range keys {
			cur := big.NewInt(0)
			cur.Mul(stakingNetwork.BlockReward, big.NewInt(int64(i+1))).Div(cur, count)
			reward := big.NewInt(0).Sub(cur, last)
			rewardsForThisAddr = new(big.Int).Add(reward, rewardsForThisAddr)
			last = cur
			i++
		}
		if sigAddr == address {
			rewardsForThisBlock = rewardsForThisAddr
			if !(rewardsForThisAddr.Cmp(big.NewInt(0)) > 0) {
				return nil, common.NewError(common.SanityCheckError, map[string]interface{}{
					"message": "expected non-zero block reward in pre-staking era for block signer",
				})
			}
			break
		}
	}

	return &types.Transaction{
		TransactionIdentifier: txID,
		Operations: []*types.Operation{
			{
				OperationIdentifier: &types.OperationIdentifier{
					Index: 0,
				},
				Type:    common.PreStakingBlockRewardOperation,
				Status:  common.SuccessOperationStatus.Status,
				Account: accID,
				Amount: &types.Amount{
					Value:    fmt.Sprintf("%v", rewardsForThisBlock),
					Currency: &common.Currency,
				},
			},
		},
	}, nil
}

// formatUndelegationPayoutTransaction for undelegation payouts at committee selection block
func formatUndelegationPayoutTransaction(
	txID *types.TransactionIdentifier, delegatorPayouts hmy.UndelegationPayouts, address ethcommon.Address,
) (*types.Transaction, *types.Error) {
	accID, rosettaError := newAccountIdentifier(address)
	if rosettaError != nil {
		return nil, rosettaError
	}
	payout, ok := delegatorPayouts[address]
	if !ok {
		return nil, &common.TransactionNotFoundError
	}
	return &types.Transaction{
		TransactionIdentifier: txID,
		Operations: []*types.Operation{
			{
				OperationIdentifier: &types.OperationIdentifier{
					Index: 0,
				},
				Type:    common.UndelegationPayoutOperation,
				Status:  common.SuccessOperationStatus.Status,
				Account: accID,
				Amount: &types.Amount{
					Value:    fmt.Sprintf("%v", payout),
					Currency: &common.Currency,
				},
			},
		},
	}, nil

}

var (
	// DefaultSenderAddress ..
	DefaultSenderAddress = ethcommon.HexToAddress("0xEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE")
)

// formatTransaction for staking, cross-shard sender, and plain transactions
func formatTransaction(
	tx hmytypes.PoolTransaction, receipt *hmytypes.Receipt,
) (fmtTx *types.Transaction, rosettaError *types.Error) {
	var operations []*types.Operation
	var isCrossShard, isStaking bool
	var toShard uint32

	switch tx.(type) {
	case *stakingTypes.StakingTransaction:
		isStaking = true
		stakingTx := tx.(*stakingTypes.StakingTransaction)
		operations, rosettaError = getStakingOperations(stakingTx, receipt)
		if rosettaError != nil {
			return nil, rosettaError
		}
		isCrossShard = false
		toShard = stakingTx.ShardID()
	case *hmytypes.Transaction:
		isStaking = false
		plainTx := tx.(*hmytypes.Transaction)
		operations, rosettaError = getOperations(plainTx, receipt)
		if rosettaError != nil {
			return nil, rosettaError
		}
		isCrossShard = plainTx.ShardID() != plainTx.ToShardID()
		toShard = plainTx.ToShardID()
	default:
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": "unknown transaction type",
		})
	}
	fromShard := tx.ShardID()
	txID := &types.TransactionIdentifier{Hash: tx.Hash().String()}

	// Set all possible metadata
	var txMetadata TransactionMetadata
	if isCrossShard {
		txMetadata.CrossShardIdentifier = txID
		txMetadata.ToShardID = &toShard
		txMetadata.FromShardID = &fromShard
	}
	if len(tx.Data()) > 0 && !isStaking {
		hexData := hex.EncodeToString(tx.Data())
		txMetadata.Data = &hexData
		txMetadata.Logs = receipt.Logs
	}
	metadata, err := types.MarshalMap(txMetadata)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	return &types.Transaction{
		TransactionIdentifier: txID,
		Operations:            operations,
		Metadata:              metadata,
	}, nil
}

// getOperations for one of the following transactions:
// contract creation, cross-shard sender, same-shard transfer
func getOperations(
	tx *hmytypes.Transaction, receipt *hmytypes.Receipt,
) ([]*types.Operation, *types.Error) {
	senderAddress, err := tx.SenderAddress()
	if err != nil {
		senderAddress = DefaultSenderAddress
	}
	accountID, rosettaError := newAccountIdentifier(senderAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}

	// All operations excepts for cross-shard tx payout expend gas
	gasExpended := new(big.Int).Mul(new(big.Int).SetUint64(receipt.GasUsed), tx.GasPrice())
	gasOperations := newOperations(gasExpended, accountID)

	// Handle different cases of plain transactions
	var txOperations []*types.Operation
	if tx.To() == nil {
		txOperations, rosettaError = newContractCreationOperations(
			gasOperations[0].OperationIdentifier, tx, receipt, senderAddress,
		)
	} else if tx.ShardID() != tx.ToShardID() {
		txOperations, rosettaError = newCrossShardSenderTransferOperations(
			gasOperations[0].OperationIdentifier, tx, senderAddress,
		)
	} else {
		txOperations, rosettaError = newTransferOperations(
			gasOperations[0].OperationIdentifier, tx, receipt, senderAddress,
		)
	}
	if rosettaError != nil {
		return nil, rosettaError
	}

	return append(gasOperations, txOperations...), nil
}

// getStakingOperations for all staking directives
func getStakingOperations(
	tx *stakingTypes.StakingTransaction, receipt *hmytypes.Receipt,
) ([]*types.Operation, *types.Error) {
	senderAddress, err := tx.SenderAddress()
	if err != nil {
		senderAddress = DefaultSenderAddress
	}
	accountID, rosettaError := newAccountIdentifier(senderAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}

	// All operations excepts for cross-shard tx payout expend gas
	gasExpended := new(big.Int).Mul(new(big.Int).SetUint64(receipt.GasUsed), tx.GasPrice())
	gasOperations := newOperations(gasExpended, accountID)

	// Format staking message for metadata using decimal numbers (hence usage of rpcV2)
	rpcStakingTx, err := rpcV2.NewStakingTransaction(tx, ethcommon.Hash{}, 0, 0, 0)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	metadata, err := types.MarshalMap(rpcStakingTx.Msg)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	// Set correct amount depending on staking message directive that apply balance changes INSTANTLY
	var amount *types.Amount
	switch tx.StakingType() {
	case stakingTypes.DirectiveCreateValidator:
		if amount, rosettaError = getAmountFromCreateValidatorMessage(tx.Data()); rosettaError != nil {
			return nil, rosettaError
		}
	case stakingTypes.DirectiveDelegate:
		if amount, rosettaError = getAmountFromDelegateMessage(receipt, tx.Data()); rosettaError != nil {
			return nil, rosettaError
		}
	case stakingTypes.DirectiveCollectRewards:
		if amount, rosettaError = getAmountFromCollectRewards(receipt, senderAddress); rosettaError != nil {
			return nil, rosettaError
		}
	default:
		amount = &types.Amount{
			Value:    "0", // All other staking transactions do not apply balance changes instantly or at all
			Currency: &common.Currency,
		}
	}

	return append(gasOperations, &types.Operation{
		OperationIdentifier: &types.OperationIdentifier{
			Index: gasOperations[0].OperationIdentifier.Index + 1,
		},
		RelatedOperations: []*types.OperationIdentifier{
			gasOperations[0].OperationIdentifier,
		},
		Type:     tx.StakingType().String(),
		Status:   common.SuccessOperationStatus.Status,
		Account:  accountID,
		Amount:   amount,
		Metadata: metadata,
	}), nil
}

func getAmountFromCreateValidatorMessage(data []byte) (*types.Amount, *types.Error) {
	msg, err := stakingTypes.RLPDecodeStakeMsg(data, stakingTypes.DirectiveCreateValidator)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	stkMsg, ok := msg.(*stakingTypes.CreateValidator)
	if !ok {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": "unable to parse staking message for create validator tx",
		})
	}
	return &types.Amount{
		Value:    formatNegativeValue(stkMsg.Amount),
		Currency: &common.Currency,
	}, nil
}

func getAmountFromDelegateMessage(receipt *hmytypes.Receipt, data []byte) (*types.Amount, *types.Error) {
	msg, err := stakingTypes.RLPDecodeStakeMsg(data, stakingTypes.DirectiveDelegate)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	stkMsg, ok := msg.(*stakingTypes.Delegate)
	if !ok {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": "unable to parse staking message for delegate tx",
		})
	}

	stkAmount := stkMsg.Amount
	logs := findLogsWithTopic(receipt, staking.DelegateTopic)
	for _, log := range logs {
		if len(log.Data) > ethcommon.AddressLength {
			validatorAddress := ethcommon.BytesToAddress(log.Data[:ethcommon.AddressLength])
			if log.Address == stkMsg.DelegatorAddress && stkMsg.ValidatorAddress == validatorAddress {
				// Remove re-delegation amount as funds were never credited to account's balance.
				stkAmount = new(big.Int).Sub(stkAmount, new(big.Int).SetBytes(log.Data[ethcommon.AddressLength:]))
				break
			}
		}
	}
	return &types.Amount{
		Value:    formatNegativeValue(stkAmount),
		Currency: &common.Currency,
	}, nil
}

func getAmountFromCollectRewards(
	receipt *hmytypes.Receipt, senderAddress ethcommon.Address,
) (*types.Amount, *types.Error) {
	var amount *types.Amount
	logs := findLogsWithTopic(receipt, staking.CollectRewardsTopic)
	for _, log := range logs {
		if log.Address == senderAddress {
			amount = &types.Amount{
				Value:    fmt.Sprintf("%v", big.NewInt(0).SetBytes(log.Data)),
				Currency: &common.Currency,
			}
			break
		}
	}
	if amount == nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": fmt.Sprintf("collect rewards amount not found for %v", senderAddress),
		})
	}
	return amount, nil
}

// newTransferOperations extracts & formats the operation(s) for plain transaction,
// including contract transactions.
func newTransferOperations(
	startingOperationID *types.OperationIdentifier,
	tx *hmytypes.Transaction, receipt *hmytypes.Receipt, senderAddress ethcommon.Address,
) ([]*types.Operation, *types.Error) {
	if tx.To() == nil {
		return nil, common.NewError(common.CatchAllError, nil)
	}
	receiverAddress := *tx.To()

	// Common elements
	opType := common.TransferOperation
	opStatus := common.SuccessOperationStatus.Status
	if receipt.Status == hmytypes.ReceiptStatusFailed {
		if len(tx.Data()) > 0 {
			opStatus = common.ContractFailureOperationStatus.Status
		} else {
			// Should never see a failed non-contract related transaction on chain
			opStatus = common.FailureOperationStatus.Status
			utils.Logger().Warn().Msgf("Failed transaction on chain: %v", tx.Hash().String())
		}
	}

	// Subtraction operation elements
	subOperationID := &types.OperationIdentifier{
		Index: startingOperationID.Index + 1,
	}
	subRelatedID := []*types.OperationIdentifier{
		startingOperationID,
	}
	subAccountID, rosettaError := newAccountIdentifier(senderAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}
	subAmount := &types.Amount{
		Value:    formatNegativeValue(tx.Value()),
		Currency: &common.Currency,
	}

	// Addition operation elements
	addOperationID := &types.OperationIdentifier{
		Index: subOperationID.Index + 1,
	}
	addRelatedID := []*types.OperationIdentifier{
		subOperationID,
	}
	addAccountID, rosettaError := newAccountIdentifier(receiverAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}
	addAmount := &types.Amount{
		Value:    fmt.Sprintf("%v", tx.Value()),
		Currency: &common.Currency,
	}

	return []*types.Operation{
		{
			OperationIdentifier: subOperationID,
			RelatedOperations:   subRelatedID,
			Type:                opType,
			Status:              opStatus,
			Account:             subAccountID,
			Amount:              subAmount,
		},
		{
			OperationIdentifier: addOperationID,
			RelatedOperations:   addRelatedID,
			Type:                opType,
			Status:              opStatus,
			Account:             addAccountID,
			Amount:              addAmount,
		},
	}, nil
}

// newCrossShardSenderTransferOperations extracts & formats the operation(s) for cross-shard-tx
// on the sender's shard.
func newCrossShardSenderTransferOperations(
	startingOperationID *types.OperationIdentifier,
	tx *hmytypes.Transaction, senderAddress ethcommon.Address,
) ([]*types.Operation, *types.Error) {
	if tx.To() == nil {
		return nil, common.NewError(common.CatchAllError, nil)
	}
	senderAccountID, rosettaError := newAccountIdentifier(senderAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}
	receiverAccountID, rosettaError := newAccountIdentifier(*tx.To())
	if rosettaError != nil {
		return nil, rosettaError
	}
	metadata, err := types.MarshalMap(common.CrossShardTransactionOperationMetadata{
		From: senderAccountID,
		To:   receiverAccountID,
	})
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	return []*types.Operation{
		{
			OperationIdentifier: &types.OperationIdentifier{
				Index: startingOperationID.Index + 1,
			},
			RelatedOperations: []*types.OperationIdentifier{
				startingOperationID,
			},
			Type:    common.CrossShardTransferOperation,
			Status:  common.SuccessOperationStatus.Status,
			Account: senderAccountID,
			Amount: &types.Amount{
				Value:    formatNegativeValue(tx.Value()),
				Currency: &common.Currency,
			},
			Metadata: metadata,
		},
	}, nil
}

// newContractCreationOperations extracts & formats the operation(s) for a contract creation tx
func newContractCreationOperations(
	startingOperationID *types.OperationIdentifier,
	tx *hmytypes.Transaction, txReceipt *hmytypes.Receipt, senderAddress ethcommon.Address,
) ([]*types.Operation, *types.Error) {
	senderAccountID, rosettaError := newAccountIdentifier(senderAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}

	// Set execution status as necessary
	status := common.SuccessOperationStatus.Status
	if txReceipt.Status == hmytypes.ReceiptStatusFailed {
		status = common.ContractFailureOperationStatus.Status
	}
	contractAddressID, rosettaError := newAccountIdentifier(txReceipt.ContractAddress)
	if rosettaError != nil {
		return nil, rosettaError
	}

	return []*types.Operation{
		{
			OperationIdentifier: &types.OperationIdentifier{
				Index: startingOperationID.Index + 1,
			},
			RelatedOperations: []*types.OperationIdentifier{
				startingOperationID,
			},
			Type:    common.ContractCreationOperation,
			Status:  status,
			Account: senderAccountID,
			Amount: &types.Amount{
				Value:    formatNegativeValue(tx.Value()),
				Currency: &common.Currency,
			},
			Metadata: map[string]interface{}{
				"contract_address": contractAddressID,
			},
		},
	}, nil
}

// AccountMetadata used for account identifiers
type AccountMetadata struct {
	Address string `json:"hex_address"`
}

// newAccountIdentifier ..
func newAccountIdentifier(
	address ethcommon.Address,
) (*types.AccountIdentifier, *types.Error) {
	b32Address, err := internalCommon.AddressToBech32(address)
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}
	metadata, err := types.MarshalMap(AccountMetadata{Address: address.String()})
	if err != nil {
		return nil, common.NewError(common.CatchAllError, map[string]interface{}{
			"message": err.Error(),
		})
	}

	return &types.AccountIdentifier{
		Address:  b32Address,
		Metadata: metadata,
	}, nil
}

// getAddress ..
func getAddress(
	identifier *types.AccountIdentifier,
) (ethcommon.Address, error) {
	if identifier == nil {
		return ethcommon.Address{}, fmt.Errorf("identifier cannot be nil")
	}
	return internalCommon.Bech32ToAddress(identifier.Address)
}

// newOperations creates a new operation with the gas fee as the first operation.
// Note: the gas fee is gasPrice * gasUsed.
func newOperations(
	gasFeeInATTO *big.Int, accountID *types.AccountIdentifier,
) []*types.Operation {
	return []*types.Operation{
		{
			OperationIdentifier: &types.OperationIdentifier{
				Index: 0, // gas operation is always first
			},
			Type:    common.ExpendGasOperation,
			Status:  common.SuccessOperationStatus.Status,
			Account: accountID,
			Amount: &types.Amount{
				Value:    formatNegativeValue(gasFeeInATTO),
				Currency: &common.Currency,
			},
		},
	}
}

// findLogsWithTopic returns all the logs that contain the given receipt
func findLogsWithTopic(
	receipt *hmytypes.Receipt, targetTopic ethcommon.Hash,
) []*hmytypes.Log {
	logs := []*hmytypes.Log{}
	for _, log := range receipt.Logs {
		for _, topic := range log.Topics {
			if topic == targetTopic {
				logs = append(logs, log)
				break
			}
		}
	}
	return logs
}

// formatNegativeValue ..
func formatNegativeValue(num *big.Int) string {
	value := "0"
	if num != nil && num.Cmp(big.NewInt(0)) == 1 {
		value = fmt.Sprintf("-%v", new(big.Int).Abs(num))
	}
	return value
}

// getGenesisSpec ..
func getGenesisSpec(shardID uint32) *core.Genesis {
	if shard.Schedule.GetNetworkID() == shardingconfig.MainNet {
		return core.NewGenesisSpec(nodeconfig.Mainnet, shardID)
	}
	if shard.Schedule.GetNetworkID() == shardingconfig.LocalNet {
		return core.NewGenesisSpec(nodeconfig.Localnet, shardID)
	}
	return core.NewGenesisSpec(nodeconfig.Testnet, shardID)
}