package account

import (
	"context"
	"encoding/hex"
	"encoding/json"

	"github.com/bytom/blockchain/signers"
	"github.com/bytom/blockchain/txbuilder"
	"github.com/bytom/common"
	"github.com/bytom/consensus"
	"github.com/bytom/crypto/ed25519/chainkd"
	chainjson "github.com/bytom/encoding/json"
	"github.com/bytom/errors"
	"github.com/bytom/protocol/bc"
	"github.com/bytom/protocol/bc/types"
	"github.com/bytom/protocol/vm/vmutil"
)

//DecodeSpendAction unmarshal JSON-encoded data of spend action
func (m *Manager) DecodeSpendAction(data []byte) (txbuilder.Action, error) {
	a := &spendAction{accounts: m}
	return a, json.Unmarshal(data, a)
}

type spendAction struct {
	accounts *Manager
	bc.AssetAmount
	AccountID      string `json:"account_id"`
	UseUnconfirmed bool   `json:"use_unconfirmed"`
}

// MergeSpendAction merge common assetID and accountID spend action
func MergeSpendAction(actions []txbuilder.Action) []txbuilder.Action {
	resultActions := []txbuilder.Action{}
	spendActionMap := make(map[string]*spendAction)

	for _, act := range actions {
		switch act := act.(type) {
		case *spendAction:
			actionKey := act.AssetId.String() + act.AccountID
			if tmpAct, ok := spendActionMap[actionKey]; ok {
				tmpAct.Amount += act.Amount
				tmpAct.UseUnconfirmed = tmpAct.UseUnconfirmed || act.UseUnconfirmed
			} else {
				spendActionMap[actionKey] = act
				resultActions = append(resultActions, act)
			}
		default:
			resultActions = append(resultActions, act)
		}
	}
	return resultActions
}

func (a *spendAction) Build(ctx context.Context, b *txbuilder.TemplateBuilder) error {
	var missing []string
	if a.AccountID == "" {
		missing = append(missing, "account_id")
	}
	if a.AssetId.IsZero() {
		missing = append(missing, "asset_id")
	}
	if len(missing) > 0 {
		return txbuilder.MissingFieldsError(missing...)
	}

	acct, err := a.accounts.FindByID(a.AccountID)
	if err != nil {
		return errors.Wrap(err, "get account info")
	}

	res, err := a.accounts.utxoKeeper.Reserve(a.AccountID, a.AssetId, a.Amount, a.UseUnconfirmed, b.MaxTime())
	if err != nil {
		return errors.Wrap(err, "reserving utxos")
	}

	// Cancel the reservation if the build gets rolled back.
	b.OnRollback(func() { a.accounts.utxoKeeper.Cancel(res.id) })
	for _, r := range res.utxos {
		txInput, sigInst, err := UtxoToInputs(acct.Signer, r)
		if err != nil {
			return errors.Wrap(err, "creating inputs")
		}

		if err = b.AddInput(txInput, sigInst); err != nil {
			return errors.Wrap(err, "adding inputs")
		}
	}

	if res.change > 0 {
		acp, err := a.accounts.CreateAddress(a.AccountID, true)
		if err != nil {
			return errors.Wrap(err, "creating control program")
		}

		// Don't insert the control program until callbacks are executed.
		a.accounts.insertControlProgramDelayed(b, acp)
		if err = b.AddOutput(types.NewTxOutput(*a.AssetId, res.change, acp.ControlProgram)); err != nil {
			return errors.Wrap(err, "adding change output")
		}
	}
	return nil
}

//DecodeSpendUTXOAction unmarshal JSON-encoded data of spend utxo action
func (m *Manager) DecodeSpendUTXOAction(data []byte) (txbuilder.Action, error) {
	a := &spendUTXOAction{accounts: m}
	return a, json.Unmarshal(data, a)
}

type spendUTXOAction struct {
	accounts       *Manager
	OutputID       *bc.Hash           `json:"output_id"`
	UseUnconfirmed bool               `json:"use_unconfirmed"`
	Arguments      []contractArgument `json:"arguments"`
}

// contractArgument for smart contract
type contractArgument struct {
	Type    string          `json:"type"`
	RawData json.RawMessage `json:"raw_data"`
}

// rawTxSigArgument is signature-related argument for run contract
type rawTxSigArgument struct {
	RootXPub chainkd.XPub         `json:"xpub"`
	Path     []chainjson.HexBytes `json:"derivation_path"`
}

// dataArgument is the other argument for run contract
type dataArgument struct {
	Value string `json:"value"`
}

func (a *spendUTXOAction) Build(ctx context.Context, b *txbuilder.TemplateBuilder) error {
	if a.OutputID == nil {
		return txbuilder.MissingFieldsError("output_id")
	}

	res, err := a.accounts.utxoKeeper.ReserveParticular(*a.OutputID, a.UseUnconfirmed, b.MaxTime())
	if err != nil {
		return err
	}

	b.OnRollback(func() { a.accounts.utxoKeeper.Cancel(res.id) })
	var accountSigner *signers.Signer
	if len(res.utxos[0].AccountID) != 0 {
		account, err := a.accounts.FindByID(res.utxos[0].AccountID)
		if err != nil {
			return err
		}

		accountSigner = account.Signer
	}

	txInput, sigInst, err := UtxoToInputs(accountSigner, res.utxos[0])
	if err != nil {
		return err
	}

	if a.Arguments == nil {
		return b.AddInput(txInput, sigInst)
	}

	sigInst = &txbuilder.SigningInstruction{}
	for _, arg := range a.Arguments {
		switch arg.Type {
		case "raw_tx_signature":
			rawTxSig := &rawTxSigArgument{}
			if err = json.Unmarshal(arg.RawData, rawTxSig); err != nil {
				return err
			}

			// convert path form chainjson.HexBytes to byte
			var path [][]byte
			for _, p := range rawTxSig.Path {
				path = append(path, []byte(p))
			}
			sigInst.AddRawWitnessKeys([]chainkd.XPub{rawTxSig.RootXPub}, path, 1)

		case "data":
			data := &dataArgument{}
			if err = json.Unmarshal(arg.RawData, data); err != nil {
				return err
			}

			value, err := hex.DecodeString(data.Value)
			if err != nil {
				return err
			}
			sigInst.WitnessComponents = append(sigInst.WitnessComponents, txbuilder.DataWitness(value))

		default:
			return errors.New("contract argument type is not exist")
		}
	}
	return b.AddInput(txInput, sigInst)
}

// UtxoToInputs convert an utxo to the txinput
func UtxoToInputs(signer *signers.Signer, u *UTXO) (*types.TxInput, *txbuilder.SigningInstruction, error) {
	txInput := types.NewSpendInput(nil, u.SourceID, u.AssetID, u.Amount, u.SourcePos, u.ControlProgram)
	sigInst := &txbuilder.SigningInstruction{}
	if signer == nil {
		return txInput, sigInst, nil
	}

	path := signers.Path(signer, signers.AccountKeySpace, u.ControlProgramIndex)
	if u.Address == "" {
		sigInst.AddWitnessKeys(signer.XPubs, path, signer.Quorum)
		return txInput, sigInst, nil
	}

	address, err := common.DecodeAddress(u.Address, &consensus.ActiveNetParams)
	if err != nil {
		return nil, nil, err
	}

	switch address.(type) {
	case *common.AddressWitnessPubKeyHash:
		sigInst.AddRawWitnessKeys(signer.XPubs, path, signer.Quorum)
		derivedXPubs := chainkd.DeriveXPubs(signer.XPubs, path)
		derivedPK := derivedXPubs[0].PublicKey()
		sigInst.WitnessComponents = append(sigInst.WitnessComponents, txbuilder.DataWitness([]byte(derivedPK)))

	case *common.AddressWitnessScriptHash:
		sigInst.AddRawWitnessKeys(signer.XPubs, path, signer.Quorum)
		path := signers.Path(signer, signers.AccountKeySpace, u.ControlProgramIndex)
		derivedXPubs := chainkd.DeriveXPubs(signer.XPubs, path)
		derivedPKs := chainkd.XPubKeys(derivedXPubs)
		script, err := vmutil.P2SPMultiSigProgram(derivedPKs, signer.Quorum)
		if err != nil {
			return nil, nil, err
		}
		sigInst.WitnessComponents = append(sigInst.WitnessComponents, txbuilder.DataWitness(script))

	default:
		return nil, nil, errors.New("unsupport address type")
	}

	return txInput, sigInst, nil
}

// insertControlProgramDelayed takes a template builder and an account
// control program that hasn't been inserted to the database yet. It
// registers callbacks on the TemplateBuilder so that all of the template's
// account control programs are batch inserted if building the rest of
// the template is successful.
func (m *Manager) insertControlProgramDelayed(b *txbuilder.TemplateBuilder, acp *CtrlProgram) {
	m.delayedACPsMu.Lock()
	m.delayedACPs[b] = append(m.delayedACPs[b], acp)
	m.delayedACPsMu.Unlock()

	b.OnRollback(func() {
		m.delayedACPsMu.Lock()
		delete(m.delayedACPs, b)
		m.delayedACPsMu.Unlock()
	})
	b.OnBuild(func() error {
		m.delayedACPsMu.Lock()
		acps := m.delayedACPs[b]
		delete(m.delayedACPs, b)
		m.delayedACPsMu.Unlock()

		// Insert all of the account control programs at once.
		if len(acps) == 0 {
			return nil
		}
		return m.insertControlPrograms(acps...)
	})
}