package indexer

import (
	"context"
	"oc-discovery/conf"
	"oc-discovery/daemons/node/common"
	"sync"

	oclib "cloud.o-forge.io/core/oc-lib"
	dht "github.com/libp2p/go-libp2p-kad-dht"
	pubsub "github.com/libp2p/go-libp2p-pubsub"
	record "github.com/libp2p/go-libp2p-record"
	"github.com/libp2p/go-libp2p/core/host"
)

// IndexerService manages the indexer node's state: stream records, DHT, pubsub.
type IndexerService struct {
	*common.LongLivedStreamRecordedService[PeerRecord]
	PS              *pubsub.PubSub
	DHT             *dht.IpfsDHT
	isStrictIndexer bool
	mu              sync.RWMutex
	IsNative        bool
	Native          *NativeState // non-nil when IsNative == true
}

// NewIndexerService creates an IndexerService.
// If ps is nil, this is a strict indexer (no pre-existing gossip sub from a node).
func NewIndexerService(h host.Host, ps *pubsub.PubSub, maxNode int, isNative bool) *IndexerService {
	logger := oclib.GetLogger()
	logger.Info().Msg("open indexer mode...")
	var err error
	ix := &IndexerService{
		LongLivedStreamRecordedService: common.NewStreamRecordedService[PeerRecord](h, maxNode),
		isStrictIndexer:                ps == nil,
		IsNative:                       isNative,
	}
	if ps == nil {
		ps, err = pubsub.NewGossipSub(context.Background(), ix.Host)
		if err != nil {
			panic(err) // can't run your indexer without a propagation pubsub
		}
	}
	ix.PS = ps

	if ix.isStrictIndexer {
		logger.Info().Msg("connect to indexers as strict indexer...")
		common.ConnectToIndexers(h, 0, 5, ix.Host.ID())
		logger.Info().Msg("subscribe to decentralized search flow as strict indexer...")
		ix.SubscribeToSearch(ix.PS, nil)
	}

	if ix.DHT, err = dht.New(
		context.Background(),
		ix.Host,
		dht.Mode(dht.ModeServer),
		dht.Validator(record.NamespacedValidator{
			"node":    PeerRecordValidator{},
			"indexer": IndexerRecordValidator{}, // for native indexer registry
		}),
	); err != nil {
		return nil
	}

	// InitNative must happen after DHT is ready
	if isNative {
		ix.InitNative()
	} else {
		ix.initNodeHandler()
	}

	// Register with configured natives so this indexer appears in their cache
	if nativeAddrs := conf.GetConfig().NativeIndexerAddresses; nativeAddrs != "" {
		StartNativeRegistration(ix.Host, nativeAddrs)
	}
	return ix
}

func (ix *IndexerService) Close() {
	ix.DHT.Close()
	ix.PS.UnregisterTopicValidator(common.TopicPubSubSearch)
	for _, s := range ix.StreamRecords {
		for _, ss := range s {
			ss.HeartbeatStream.Stream.Close()
		}
	}
}