package libp2p

import (
	"context"
	"fmt"

	"github.com/ipfs/go-datastore"
	nilrouting "github.com/ipfs/go-ipfs-routing/none"
	"github.com/libp2p/go-libp2p"
	host "github.com/libp2p/go-libp2p-core/host"
	peer "github.com/libp2p/go-libp2p-core/peer"
	peerstore "github.com/libp2p/go-libp2p-core/peerstore"
	dht "github.com/libp2p/go-libp2p-kad-dht"
	dhtopts "github.com/libp2p/go-libp2p-kad-dht/opts"
	record "github.com/libp2p/go-libp2p-record"
	routedhost "github.com/libp2p/go-libp2p/p2p/host/routed"
	mocknet "github.com/libp2p/go-libp2p/p2p/net/mock"
	"go.uber.org/fx"

	"github.com/filecoin-project/go-lotus/node/modules/helpers"
)

type P2PHostIn struct {
	fx.In

	ID        peer.ID
	Peerstore peerstore.Peerstore

	Opts [][]libp2p.Option `group:"libp2p"`
}

// ////////////////////////

type RawHost host.Host

func Host(mctx helpers.MetricsCtx, lc fx.Lifecycle, params P2PHostIn) (RawHost, error) {
	ctx := helpers.LifecycleCtx(mctx, lc)

	pkey := params.Peerstore.PrivKey(params.ID)
	if pkey == nil {
		return nil, fmt.Errorf("missing private key for node ID: %s", params.ID.Pretty())
	}

	opts := []libp2p.Option{libp2p.Identity(pkey), libp2p.Peerstore(params.Peerstore), libp2p.NoListenAddrs}
	for _, o := range params.Opts {
		opts = append(opts, o...)
	}

	h, err := libp2p.New(ctx, opts...)
	if err != nil {
		return nil, err
	}

	lc.Append(fx.Hook{
		OnStop: func(ctx context.Context) error {
			return h.Close()
		},
	})

	return h, nil
}

func MockHost(mn mocknet.Mocknet, id peer.ID, ps peerstore.Peerstore) (RawHost, error) {
	return mn.AddPeerWithPeerstore(id, ps)
}

func DHTRouting(client bool) interface{} {
	return func(mctx helpers.MetricsCtx, lc fx.Lifecycle, host RawHost, dstore datastore.Batching, validator record.Validator) (BaseIpfsRouting, error) {
		ctx := helpers.LifecycleCtx(mctx, lc)

		d, err := dht.New(
			ctx, host,
			dhtopts.Client(client),
			dhtopts.Datastore(dstore),
			dhtopts.Validator(validator),
		)

		if err != nil {
			return nil, err
		}

		lc.Append(fx.Hook{
			OnStop: func(ctx context.Context) error {
				return d.Close()
			},
		})

		return d, nil
	}
}

func NilRouting(mctx helpers.MetricsCtx) (BaseIpfsRouting, error) {
	return nilrouting.ConstructNilRouting(mctx, nil, nil, nil)
}

func RoutedHost(rh RawHost, r BaseIpfsRouting) host.Host {
	return routedhost.Wrap(rh, r)
}