package main

import (
	"bytes"
	"context"
	"net"

	containerGRPC "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/container/grpc"
	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
	containerCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/container"
	cntClient "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client/container"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/client/frostfsid"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/event"
	containerEvent "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/morph/event/container"
	containerTransportGRPC "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/network/transport/container/grpc"
	containerService "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/container"
	containerMorph "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/container/morph"
	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
	"go.uber.org/zap"
	"google.golang.org/grpc"
)

func initContainerService(_ context.Context, c *cfg) {
	// container wrapper that tries to invoke notary
	// requests if chain is configured so
	wrap, err := cntClient.NewFromMorph(c.cfgMorph.client, c.cfgContainer.scriptHash, 0, cntClient.TryNotary())
	fatalOnErr(err)

	c.shared.cnrClient = wrap

	cnrSrc := cntClient.AsContainerSource(wrap)

	cnrRdr, cnrWrt := configureEACLAndContainerSources(c, wrap, cnrSrc)

	frostFSIDClient, err := frostfsid.NewFromMorph(c.cfgMorph.client, c.cfgFrostfsID.scriptHash, 0)
	fatalOnErr(err)

	server := containerTransportGRPC.New(
		containerService.NewSignService(
			&c.key.PrivateKey,
			containerService.NewAPEServer(c.cfgObject.cfgAccessPolicyEngine.accessPolicyEngine, cnrRdr,
				newCachedIRFetcher(createInnerRingFetcher(c)), c.netMapSource, frostFSIDClient,
				containerService.NewExecutionService(containerMorph.NewExecutor(cnrRdr, cnrWrt), c.respSvc),
			),
		),
	)

	c.cfgGRPC.performAndSave(func(_ string, _ net.Listener, s *grpc.Server) {
		containerGRPC.RegisterContainerServiceServer(s, server)
	})

	c.cfgObject.cfgLocalStorage.localStorage.SetContainerSource(cnrRdr)
}

func configureEACLAndContainerSources(c *cfg, client *cntClient.Client, cnrSrc containerCore.Source) (*morphContainerReader, *morphContainerWriter) {
	eACLFetcher := &morphEACLFetcher{
		w: client,
	}

	cnrRdr := new(morphContainerReader)

	cnrWrt := &morphContainerWriter{
		neoClient: client,
	}

	if c.cfgMorph.cacheTTL <= 0 {
		c.cfgObject.eaclSource = eACLFetcher
		cnrRdr.eacl = eACLFetcher
		c.cfgObject.cnrSource = cnrSrc
		cnrRdr.src = cnrSrc
		cnrRdr.lister = client
	} else {
		// use RPC node as source of Container contract items (with caching)
		cachedContainerStorage := newCachedContainerStorage(cnrSrc, c.cfgMorph.cacheTTL)
		cachedEACLStorage := newCachedEACLStorage(eACLFetcher, c.cfgMorph.cacheTTL)

		subscribeToContainerCreation(c, func(e event.Event) {
			ev := e.(containerEvent.PutSuccess)

			// read owner of the created container in order to update the reading cache.
			// TODO: use owner directly from the event after neofs-contract#256 will become resolved
			//  but don't forget about the profit of reading the new container and caching it:
			//  creation success are most commonly tracked by polling GET op.
			cnr, err := cnrSrc.Get(ev.ID)
			if err == nil {
				cachedContainerStorage.containerCache.set(ev.ID, cnr, nil)
			} else {
				// unlike removal, we expect successful receive of the container
				// after successful creation, so logging can be useful
				c.log.Error(logs.FrostFSNodeReadNewlyCreatedContainerAfterTheNotification,
					zap.Stringer("id", ev.ID),
					zap.Error(err),
				)
			}

			c.log.Debug(logs.FrostFSNodeContainerCreationEventsReceipt,
				zap.Stringer("id", ev.ID),
			)
		})

		subscribeToContainerRemoval(c, func(e event.Event) {
			ev := e.(containerEvent.DeleteSuccess)
			cachedContainerStorage.handleRemoval(ev.ID)
			c.log.Debug(logs.FrostFSNodeContainerRemovalEventsReceipt,
				zap.Stringer("id", ev.ID),
			)
		})

		c.cfgObject.eaclSource = cachedEACLStorage
		c.cfgObject.cnrSource = cachedContainerStorage

		cnrRdr.lister = client
		cnrRdr.eacl = c.cfgObject.eaclSource
		cnrRdr.src = c.cfgObject.cnrSource

		cnrWrt.cacheEnabled = true
		cnrWrt.eacls = cachedEACLStorage
	}

	return cnrRdr, cnrWrt
}

// addContainerNotificationHandler adds handler that will be executed synchronously.
func addContainerNotificationHandler(c *cfg, sTyp string, h event.Handler) {
	typ := event.TypeFromString(sTyp)

	if c.cfgContainer.subscribers == nil {
		c.cfgContainer.subscribers = make(map[event.Type][]event.Handler, 1)
	}

	c.cfgContainer.subscribers[typ] = append(c.cfgContainer.subscribers[typ], h)
}

// addContainerAsyncNotificationHandler adds handler that will be executed asynchronously via container workerPool.
func addContainerAsyncNotificationHandler(c *cfg, sTyp string, h event.Handler) {
	addContainerNotificationHandler(
		c,
		sTyp,
		event.WorkerPoolHandler(
			c.cfgContainer.workerPool,
			h,
			c.log,
		),
	)
}

// stores already registered parsers of the notification events thrown by Container contract.
// MUST NOT be used concurrently.
var mRegisteredParsersContainer = make(map[string]struct{})

// registers event parser by name once. MUST NOT be called concurrently.
func registerEventParserOnceContainer(c *cfg, name string, p event.NotificationParser) {
	if _, ok := mRegisteredParsersContainer[name]; !ok {
		setContainerNotificationParser(c, name, p)
		mRegisteredParsersContainer[name] = struct{}{}
	}
}

// subscribes to successful container creation. Provided handler is called asynchronously
// on corresponding routine pool. MUST NOT be called concurrently with itself and other
// similar functions.
func subscribeToContainerCreation(c *cfg, h event.Handler) {
	const eventNameContainerCreated = "PutSuccess"
	registerEventParserOnceContainer(c, eventNameContainerCreated, containerEvent.ParsePutSuccess)
	addContainerAsyncNotificationHandler(c, eventNameContainerCreated, h)
}

// like subscribeToContainerCreation but for removal.
func subscribeToContainerRemoval(c *cfg, h event.Handler) {
	const eventNameContainerRemoved = "DeleteSuccess"
	registerEventParserOnceContainer(c, eventNameContainerRemoved, containerEvent.ParseDeleteSuccess)
	addContainerAsyncNotificationHandler(c, eventNameContainerRemoved, h)
}

func setContainerNotificationParser(c *cfg, sTyp string, p event.NotificationParser) {
	typ := event.TypeFromString(sTyp)

	if c.cfgContainer.parsers == nil {
		c.cfgContainer.parsers = make(map[event.Type]event.NotificationParser, 1)
	}

	c.cfgContainer.parsers[typ] = p
}

func (c *cfg) PublicKey() []byte {
	return nodeKeyFromNetmap(c)
}

func (c *cfg) IsLocalKey(key []byte) bool {
	return bytes.Equal(key, c.PublicKey())
}

func (c *cfg) IterateAddresses(f func(string) bool) {
	c.iterateNetworkAddresses(f)
}

func (c *cfg) NumberOfAddresses() int {
	return c.addressNum()
}

func (c *cfg) ExternalAddresses() []string {
	return c.cfgNodeInfo.localInfo.ExternalAddresses()
}

// implements interface required by container service provided by morph executor.
type morphContainerReader struct {
	eacl containerCore.EACLSource

	src containerCore.Source

	lister interface {
		ContainersOf(*user.ID) ([]cid.ID, error)
	}
}

func (x *morphContainerReader) Get(id cid.ID) (*containerCore.Container, error) {
	return x.src.Get(id)
}

func (x *morphContainerReader) DeletionInfo(id cid.ID) (*containerCore.DelInfo, error) {
	return x.src.DeletionInfo(id)
}

func (x *morphContainerReader) GetEACL(id cid.ID) (*containerCore.EACL, error) {
	return x.eacl.GetEACL(id)
}

func (x *morphContainerReader) ContainersOf(id *user.ID) ([]cid.ID, error) {
	return x.lister.ContainersOf(id)
}

type morphContainerWriter struct {
	neoClient *cntClient.Client

	cacheEnabled bool
	eacls        ttlEACLStorage
}

func (m morphContainerWriter) Put(cnr containerCore.Container) (*cid.ID, error) {
	return cntClient.Put(m.neoClient, cnr)
}

func (m morphContainerWriter) Delete(witness containerCore.RemovalWitness) error {
	return cntClient.Delete(m.neoClient, witness)
}

func (m morphContainerWriter) PutEACL(eaclInfo containerCore.EACL) error {
	err := cntClient.PutEACL(m.neoClient, eaclInfo)
	if err != nil {
		return err
	}

	if m.cacheEnabled {
		id, _ := eaclInfo.Value.CID()
		m.eacls.InvalidateEACL(id)
	}

	return nil
}