package container

import (
	"crypto/elliptic"
	"crypto/sha256"
	"errors"
	"fmt"

	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
	containerSDK "github.com/nspcc-dev/neofs-api-go/pkg/container"
	"github.com/nspcc-dev/neofs-node/pkg/core/container"
	containerEvent "github.com/nspcc-dev/neofs-node/pkg/morph/event/container"
	"go.uber.org/zap"
)

// Process new container from the user by checking container sanity
// and sending approve tx back to morph.
func (cp *Processor) processContainerPut(put *containerEvent.Put) {
	if !cp.alphabetState.IsAlphabet() {
		cp.log.Info("non alphabet mode, ignore container put")
		return
	}

	err := cp.checkPutContainer(put)
	if err != nil {
		cp.log.Error("put container check failed",
			zap.String("error", err.Error()),
		)

		return
	}

	cp.approvePutContainer(put)
}

func (cp *Processor) checkPutContainer(e *containerEvent.Put) error {
	// verify signature
	key, err := keys.NewPublicKeyFromBytes(e.PublicKey(), elliptic.P256())
	if err != nil {
		return fmt.Errorf("invalid key: %w", err)
	}

	binCnr := e.Container()
	tableHash := sha256.Sum256(binCnr)

	if !key.Verify(e.Signature(), tableHash[:]) {
		return errors.New("invalid signature")
	}

	// unmarshal container structure
	cnr := containerSDK.New()

	err = cnr.Unmarshal(binCnr)
	if err != nil {
		return fmt.Errorf("invalid binary container: %w", err)
	}

	// perform format check
	err = container.CheckFormat(cnr)
	if err != nil {
		return fmt.Errorf("incorrect container format: %w", err)
	}

	return cp.checkKeyOwnership(cnr, key)
}

func (cp *Processor) approvePutContainer(e *containerEvent.Put) {
	// FIXME: here we should try notary invoke
	// FIXME: here we should bind key to owner if needed
	err := cp.cnrClient.Put(e.Container(), e.PublicKey(), e.Signature())
	if err != nil {
		cp.log.Error("could not approve put container",
			zap.String("error", err.Error()),
		)
	}
}

// Process delete container operation from the user by checking container sanity
// and sending approve tx back to morph.
func (cp *Processor) processContainerDelete(delete *containerEvent.Delete) {
	if !cp.alphabetState.IsAlphabet() {
		cp.log.Info("non alphabet mode, ignore container delete")
		return
	}

	err := cp.checkDeleteContainer(delete)
	if err != nil {
		cp.log.Error("delete container check failed",
			zap.String("error", err.Error()),
		)

		return
	}

	cp.approveDeleteContainer(delete)
}

func (cp *Processor) checkDeleteContainer(e *containerEvent.Delete) error {
	cid := e.ContainerID()

	// receive owner of the related container
	cnr, err := cp.cnrClient.Get(cid)
	if err != nil {
		return fmt.Errorf("could not receive the container: %w", err)
	}

	// receive all owner keys
	ownerKeys, err := cp.idClient.AccountKeys(cnr.OwnerID())
	if err != nil {
		return fmt.Errorf("could not received owner keys %s: %w", cnr.OwnerID(), err)
	}

	// verify signature
	cidHash := sha256.Sum256(cid)
	sig := e.Signature()

	for _, ownerKey := range ownerKeys {
		if ownerKey.Verify(sig, cidHash[:]) {
			return nil
		}
	}

	return errors.New("signature verification failed on all owner keys ")
}

func (cp *Processor) approveDeleteContainer(e *containerEvent.Delete) {
	// FIXME: here we should try notary invoke
	err := cp.cnrClient.Delete(e.ContainerID(), e.Signature())
	if err != nil {
		cp.log.Error("could not approve delete container",
			zap.String("error", err.Error()),
		)
	}
}