package container

import (
	"context"
	"errors"
	"fmt"

	frostfsidclient "git.frostfs.info/TrueCloudLab/frostfs-contract/frostfsid/client"
	containercore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/container"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/innerring/metrics"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/event"
	containerEvent "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/event/container"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
	"github.com/nspcc-dev/neo-go/pkg/core/mempoolevent"
	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/panjf2000/ants/v2"
)

type (
	// AlphabetState is a callback interface for inner ring global state.
	AlphabetState interface {
		IsAlphabet(context.Context) bool
	}

	ContClient interface {
		ContractAddress() util.Uint160
		Get(cid []byte) (*containercore.Container, error)
	}

	MorphClient interface {
		NotarySignAndInvokeTX(mainTx *transaction.Transaction) error
	}

	FrostFSIDClient interface {
		GetSubject(addr util.Uint160) (*frostfsidclient.Subject, error)
	}

	// Processor of events produced by container contract in the sidechain.
	Processor struct {
		log             *logger.Logger
		metrics         metrics.Register
		pool            *ants.Pool
		alphabetState   AlphabetState
		cnrClient       ContClient // notary must be enabled
		morphClient     MorphClient
		netState        NetworkState
		frostFSIDClient FrostFSIDClient
	}

	// Params of the processor constructor.
	Params struct {
		Log             *logger.Logger
		Metrics         metrics.Register
		PoolSize        int
		AlphabetState   AlphabetState
		ContainerClient ContClient
		MorphClient     MorphClient
		NetworkState    NetworkState
		FrostFSIDClient FrostFSIDClient
	}
)

// NetworkState is an interface of a component
// that provides access to network state.
type NetworkState interface {
	// Epoch must return the number of the current epoch.
	//
	// Must return any error encountered
	// which did not allow reading the value.
	Epoch() (uint64, error)

	// HomomorphicHashDisabled must return boolean that
	// represents homomorphic network state:
	// 	* true if hashing is disabled;
	// 	* false if hashing is enabled.
	//
	// which did not allow reading the value.
	HomomorphicHashDisabled() (bool, error)
}

// New creates a container contract processor instance.
func New(p *Params) (*Processor, error) {
	switch {
	case p.Log == nil:
		return nil, errors.New("ir/container: logger is not set")
	case p.AlphabetState == nil:
		return nil, errors.New("ir/container: global state is not set")
	case p.ContainerClient == nil:
		return nil, errors.New("ir/container: Container client is not set")
	case p.MorphClient == nil:
		return nil, errors.New("ir/container: Morph client is not set")
	case p.NetworkState == nil:
		return nil, errors.New("ir/container: network state is not set")
	case p.FrostFSIDClient == nil:
		return nil, errors.New("ir/container: FrostFSID client is not set")
	}

	pool, err := ants.NewPool(p.PoolSize, ants.WithNonblocking(true))
	if err != nil {
		return nil, fmt.Errorf("ir/container: can't create worker pool: %w", err)
	}

	metricsRegister := p.Metrics
	if metricsRegister == nil {
		metricsRegister = metrics.DefaultRegister{}
	}

	return &Processor{
		log:             p.Log,
		metrics:         metricsRegister,
		pool:            pool,
		alphabetState:   p.AlphabetState,
		cnrClient:       p.ContainerClient,
		netState:        p.NetworkState,
		morphClient:     p.MorphClient,
		frostFSIDClient: p.FrostFSIDClient,
	}, nil
}

// ListenerNotificationHandlers for the 'event.Listener' event producer.
func (cp *Processor) ListenerNotificationHandlers() []event.NotificationHandlerInfo {
	return nil
}

// ListenerNotaryParsers for the 'event.Listener' notary event producer.
func (cp *Processor) ListenerNotaryParsers() []event.NotaryParserInfo {
	var (
		p event.NotaryParserInfo

		pp = make([]event.NotaryParserInfo, 0, 4)
	)

	p.SetMempoolType(mempoolevent.TransactionAdded)
	p.SetScriptHash(cp.cnrClient.ContractAddress())

	// container put
	p.SetRequestType(containerEvent.PutNotaryEvent)
	p.SetParser(containerEvent.ParsePutNotary)
	pp = append(pp, p)

	// container named put
	p.SetRequestType(containerEvent.PutNamedNotaryEvent)
	p.SetParser(containerEvent.ParsePutNamedNotary)
	pp = append(pp, p)

	// container delete
	p.SetRequestType(containerEvent.DeleteNotaryEvent)
	p.SetParser(containerEvent.ParseDeleteNotary)
	pp = append(pp, p)

	return pp
}

// ListenerNotaryHandlers for the 'event.Listener' notary event producer.
func (cp *Processor) ListenerNotaryHandlers() []event.NotaryHandlerInfo {
	var (
		h event.NotaryHandlerInfo

		hh = make([]event.NotaryHandlerInfo, 0, 4)
	)

	h.SetScriptHash(cp.cnrClient.ContractAddress())
	h.SetMempoolType(mempoolevent.TransactionAdded)

	// container put
	h.SetRequestType(containerEvent.PutNotaryEvent)
	h.SetHandler(cp.handlePut)
	hh = append(hh, h)

	// container named put (same handler)
	h.SetRequestType(containerEvent.PutNamedNotaryEvent)
	hh = append(hh, h)

	// container delete
	h.SetRequestType(containerEvent.DeleteNotaryEvent)
	h.SetHandler(cp.handleDelete)
	hh = append(hh, h)

	return hh
}