package netmap

import (
	"bytes"
	"encoding/hex"

	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
	netmapclient "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client/netmap"
	netmapEvent "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/event/netmap"
	subnetEvent "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/event/subnet"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
	subnetid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/subnet/id"
	"go.uber.org/zap"
)

// Process add peer notification by sanity check of new node
// local epoch timer.
func (np *Processor) processAddPeer(ev netmapEvent.AddPeer) {
	if !np.alphabetState.IsAlphabet() {
		np.log.Info(logs.NetmapNonAlphabetModeIgnoreNewPeerNotification)
		return
	}

	// check if notary transaction is valid, see #976
	if originalRequest := ev.NotaryRequest(); originalRequest != nil {
		tx := originalRequest.MainTransaction
		ok, err := np.netmapClient.Morph().IsValidScript(tx.Script, tx.Signers)
		if err != nil || !ok {
			np.log.Warn(logs.NetmapNonhaltNotaryTransaction,
				zap.String("method", "netmap.AddPeer"),
				zap.String("hash", tx.Hash().StringLE()),
				zap.Error(err))
			return
		}
	}

	// unmarshal node info
	var nodeInfo netmap.NodeInfo
	if err := nodeInfo.Unmarshal(ev.Node()); err != nil {
		// it will be nice to have tx id at event structure to log it
		np.log.Warn(logs.NetmapCantParseNetworkMapCandidate)
		return
	}

	// validate and update node info
	err := np.nodeValidator.VerifyAndUpdate(&nodeInfo)
	if err != nil {
		np.log.Warn(logs.NetmapCouldNotVerifyAndUpdateInformationAboutNetworkMapCandidate,
			zap.String("error", err.Error()),
		)

		return
	}

	// sort attributes to make it consistent
	nodeInfo.SortAttributes()

	// marshal updated node info structure
	nodeInfoBinary := nodeInfo.Marshal()

	keyString := netmap.StringifyPublicKey(nodeInfo)

	updated := np.netmapSnapshot.touch(keyString, np.epochState.EpochCounter(), nodeInfoBinary)

	if updated {
		np.log.Info(logs.NetmapApprovingNetworkMapCandidate,
			zap.String("key", keyString))

		prm := netmapclient.AddPeerPrm{}
		prm.SetNodeInfo(nodeInfo)

		// In notary environments we call AddPeerIR method instead of AddPeer.
		// It differs from AddPeer only by name, so we can do this in the same form.
		// See https://github.com/nspcc-dev/frostfs-contract/issues/154.
		const methodAddPeerNotary = "addPeerIR"

		if nr := ev.NotaryRequest(); nr != nil {
			// create new notary request with the original nonce
			err = np.netmapClient.Morph().NotaryInvoke(
				np.netmapClient.ContractAddress(),
				0,
				nr.MainTransaction.Nonce,
				nil,
				methodAddPeerNotary,
				nodeInfoBinary,
			)
		} else {
			// notification event case
			err = np.netmapClient.AddPeer(prm)
		}

		if err != nil {
			np.log.Error(logs.NetmapCantInvokeNetmapAddPeer, zap.Error(err))
		}
	}
}

// Process update peer notification by sending approval tx to the smart contract.
func (np *Processor) processUpdatePeer(ev netmapEvent.UpdatePeer) {
	if !np.alphabetState.IsAlphabet() {
		np.log.Info(logs.NetmapNonAlphabetModeIgnoreUpdatePeerNotification)
		return
	}

	// flag node to remove from local view, so it can be re-bootstrapped
	// again before new epoch will tick
	np.netmapSnapshot.flag(hex.EncodeToString(ev.PublicKey().Bytes()))

	var err error

	if ev.Maintenance() {
		err = np.nodeStateSettings.MaintenanceModeAllowed()
		if err != nil {
			np.log.Info(logs.NetmapPreventSwitchingNodeToMaintenanceState,
				zap.Error(err),
			)

			return
		}
	}

	if nr := ev.NotaryRequest(); nr != nil {
		err = np.netmapClient.Morph().NotarySignAndInvokeTX(nr.MainTransaction)
	} else {
		prm := netmapclient.UpdatePeerPrm{}

		switch {
		case ev.Online():
			prm.SetOnline()
		case ev.Maintenance():
			prm.SetMaintenance()
		}

		prm.SetKey(ev.PublicKey().Bytes())

		err = np.netmapClient.UpdatePeerState(prm)
	}
	if err != nil {
		np.log.Error(logs.NetmapCantInvokeNetmapUpdatePeer, zap.Error(err))
	}
}

func (np *Processor) processRemoveSubnetNode(ev subnetEvent.RemoveNode) {
	if !np.alphabetState.IsAlphabet() {
		np.log.Info(logs.NetmapNonAlphabetModeIgnoreRemoveNodeFromSubnetNotification)
		return
	}

	candidates, err := np.netmapClient.GetCandidates()
	if err != nil {
		np.log.Warn(logs.NetmapCouldNotGetNetworkMapCandidates,
			zap.Error(err),
		)
		return
	}

	rawSubnet := ev.SubnetworkID()
	var subnetToRemoveFrom subnetid.ID

	err = subnetToRemoveFrom.Unmarshal(rawSubnet)
	if err != nil {
		np.log.Warn(logs.NetmapCouldNotUnmarshalSubnetID,
			zap.Error(err),
		)
		return
	}

	if subnetid.IsZero(subnetToRemoveFrom) {
		np.log.Warn(logs.NetmapGotZeroSubnetInRemoveNodeNotification)
		return
	}

	for i := range candidates {
		if !bytes.Equal(candidates[i].PublicKey(), ev.Node()) {
			continue
		}

		err = candidates[i].IterateSubnets(func(subNetID subnetid.ID) error {
			if subNetID.Equals(subnetToRemoveFrom) {
				return netmap.ErrRemoveSubnet
			}

			return nil
		})
		if err != nil {
			np.log.Warn(logs.NetmapCouldNotIterateOverSubnetworksOfTheNode, zap.Error(err))
			np.log.Info(logs.NetmapVoteToRemoveNodeFromNetmap, zap.String("key", hex.EncodeToString(ev.Node())))

			prm := netmapclient.UpdatePeerPrm{}
			prm.SetKey(ev.Node())
			prm.SetHash(ev.TxHash())

			err = np.netmapClient.UpdatePeerState(prm)
			if err != nil {
				np.log.Error(logs.NetmapCouldNotInvokeNetmapUpdateState, zap.Error(err))
				return
			}
		} else {
			prm := netmapclient.AddPeerPrm{}
			prm.SetNodeInfo(candidates[i])
			prm.SetHash(ev.TxHash())

			err = np.netmapClient.AddPeer(prm)
			if err != nil {
				np.log.Error(logs.NetmapCouldNotInvokeNetmapAddPeer, zap.Error(err))
				return
			}
		}

		break
	}
}