package core

import (
	"crypto/rand"
	"errors"
	"fmt"
	"net/http/httptest"
	"path"
	"testing"
	"time"

	context "context"

	"github.com/ipfs/go-cid"
	"github.com/ipfs/go-delegated-routing/client"
	"github.com/ipfs/go-ipns"
	"github.com/ipfs/kubo/core/node/libp2p"
	"github.com/ipfs/kubo/repo"
	"github.com/libp2p/go-libp2p/core/crypto"
	peer "github.com/libp2p/go-libp2p/core/peer"
	"github.com/stretchr/testify/require"

	datastore "github.com/ipfs/go-datastore"
	syncds "github.com/ipfs/go-datastore/sync"
	drs "github.com/ipfs/go-delegated-routing/server"
	config "github.com/ipfs/kubo/config"
)

func TestInitialization(t *testing.T) {
	ctx := context.Background()
	id := testIdentity

	good := []*config.Config{
		{
			Identity: id,
			Addresses: config.Addresses{
				Swarm: []string{"/ip4/0.0.0.0/tcp/4001", "/ip4/0.0.0.0/udp/4001/quic"},
				API:   []string{"/ip4/127.0.0.1/tcp/8000"},
			},
		},

		{
			Identity: id,
			Addresses: config.Addresses{
				Swarm: []string{"/ip4/0.0.0.0/tcp/4001", "/ip4/0.0.0.0/udp/4001/quic"},
				API:   []string{"/ip4/127.0.0.1/tcp/8000"},
			},
		},
	}

	bad := []*config.Config{
		{},
	}

	for i, c := range good {
		r := &repo.Mock{
			C: *c,
			D: syncds.MutexWrap(datastore.NewMapDatastore()),
		}
		n, err := NewNode(ctx, &BuildCfg{Repo: r})
		if n == nil || err != nil {
			t.Error("Should have constructed.", i, err)
		}
	}

	for i, c := range bad {
		r := &repo.Mock{
			C: *c,
			D: syncds.MutexWrap(datastore.NewMapDatastore()),
		}
		n, err := NewNode(ctx, &BuildCfg{Repo: r})
		if n != nil || err == nil {
			t.Error("Should have failed to construct.", i)
		}
	}
}

var testIdentity = config.Identity{
	PeerID:  "QmNgdzLieYi8tgfo2WfTUzNVH5hQK9oAYGVf6dxN12NrHt",
	PrivKey: "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",
}

var errNotSupported = errors.New("method not supported")

func TestDelegatedRoutingSingle(t *testing.T) {
	require := require.New(t)

	pID1, priv1, err := GeneratePeerID()
	require.NoError(err)

	pID2, _, err := GeneratePeerID()
	require.NoError(err)

	theID := path.Join("/ipns", string(pID1))
	theErrorID := path.Join("/ipns", string(pID2))

	d := &delegatedRoutingService{
		goodPeerID: pID1,
		badPeerID:  pID2,
		pk1:        priv1,
	}

	url := StartRoutingServer(t, d)
	n := GetNode(t, url)

	ctx := context.Background()

	v, err := n.Routing.GetValue(ctx, theID)
	require.NoError(err)
	require.NotNil(v)
	require.Contains(string(v), "RECORD FROM SERVICE 0")

	v, err = n.Routing.GetValue(ctx, theErrorID)
	require.Nil(v)
	require.Error(err)

	err = n.Routing.PutValue(ctx, theID, v)
	require.NoError(err)

}

func TestDelegatedRoutingMulti(t *testing.T) {
	require := require.New(t)

	pID1, priv1, err := GeneratePeerID()
	require.NoError(err)

	pID2, priv2, err := GeneratePeerID()
	require.NoError(err)

	theID1 := path.Join("/ipns", string(pID1))
	theID2 := path.Join("/ipns", string(pID2))

	d1 := &delegatedRoutingService{
		goodPeerID: pID1,
		badPeerID:  pID2,
		pk1:        priv1,
		serviceID:  1,
	}

	url1 := StartRoutingServer(t, d1)

	d2 := &delegatedRoutingService{
		goodPeerID: pID2,
		badPeerID:  pID1,
		pk1:        priv2,
		serviceID:  2,
	}

	url2 := StartRoutingServer(t, d2)

	n := GetNode(t, url1, url2)

	ctx := context.Background()

	v, err := n.Routing.GetValue(ctx, theID1)
	require.NoError(err)
	require.NotNil(v)
	require.Contains(string(v), "RECORD FROM SERVICE 1")

	v, err = n.Routing.GetValue(ctx, theID2)
	require.NoError(err)
	require.NotNil(v)
	require.Contains(string(v), "RECORD FROM SERVICE 2")
}

func StartRoutingServer(t *testing.T, d drs.DelegatedRoutingService) string {
	t.Helper()

	f := drs.DelegatedRoutingAsyncHandler(d)
	svr := httptest.NewServer(f)
	t.Cleanup(func() {
		svr.Close()
	})

	return svr.URL
}

func GetNode(t *testing.T, reframeURLs ...string) *IpfsNode {
	t.Helper()

	routers := make(config.Routers)
	var routerNames []string
	for i, ru := range reframeURLs {
		rn := fmt.Sprintf("reframe-%d", i)
		routerNames = append(routerNames, rn)
		routers[rn] =
			config.RouterParser{
				Router: config.Router{
					Type: config.RouterTypeReframe,
					Parameters: &config.ReframeRouterParams{
						Endpoint: ru,
					},
				},
			}
	}

	var crs []config.ConfigRouter
	for _, rn := range routerNames {
		crs = append(crs, config.ConfigRouter{
			RouterName:   rn,
			IgnoreErrors: true,
			Timeout:      config.Duration{Duration: time.Minute},
		})
	}

	const parallelRouterName = "parallel-router"

	routers[parallelRouterName] = config.RouterParser{
		Router: config.Router{
			Type: config.RouterTypeParallel,
			Parameters: &config.ComposableRouterParams{
				Routers: crs,
			},
		},
	}
	cfg := config.Config{
		Identity: testIdentity,
		Addresses: config.Addresses{
			Swarm: []string{"/ip4/0.0.0.0/tcp/0", "/ip4/0.0.0.0/udp/0/quic"},
			API:   []string{"/ip4/127.0.0.1/tcp/0"},
		},
		Routing: config.Routing{
			Type:    "custom",
			Routers: routers,
			Methods: config.Methods{
				config.MethodNameFindPeers: config.Method{
					RouterName: parallelRouterName,
				},
				config.MethodNameFindProviders: config.Method{
					RouterName: parallelRouterName,
				},
				config.MethodNameGetIPNS: config.Method{
					RouterName: parallelRouterName,
				},
				config.MethodNameProvide: config.Method{
					RouterName: parallelRouterName,
				},
				config.MethodNamePutIPNS: config.Method{
					RouterName: parallelRouterName,
				},
			},
		},
	}

	r := &repo.Mock{
		C: cfg,
		D: syncds.MutexWrap(datastore.NewMapDatastore()),
	}

	n, err := NewNode(context.Background(),
		&BuildCfg{
			Repo:   r,
			Online: true,
			Routing: libp2p.ConstructDelegatedRouting(
				cfg.Routing.Routers,
				cfg.Routing.Methods,
				cfg.Identity.PeerID,
				cfg.Addresses.Swarm,
				cfg.Identity.PrivKey,
			),
		},
	)
	require.NoError(t, err)

	return n
}

func GeneratePeerID() (peer.ID, crypto.PrivKey, error) {
	priv, pk, err := crypto.GenerateEd25519Key(rand.Reader)
	if err != nil {
		return peer.ID(""), nil, err
	}

	pid, err := peer.IDFromPublicKey(pk)
	return pid, priv, err
}

type delegatedRoutingService struct {
	goodPeerID, badPeerID peer.ID
	pk1                   crypto.PrivKey
	serviceID             int
}

func (drs *delegatedRoutingService) FindProviders(ctx context.Context, key cid.Cid) (<-chan client.FindProvidersAsyncResult, error) {
	return nil, errNotSupported
}

func (drs *delegatedRoutingService) Provide(ctx context.Context, req *client.ProvideRequest) (<-chan client.ProvideAsyncResult, error) {
	return nil, errNotSupported
}

func (drs *delegatedRoutingService) GetIPNS(ctx context.Context, id []byte) (<-chan client.GetIPNSAsyncResult, error) {
	ctx, cancel := context.WithCancel(ctx)
	ch := make(chan client.GetIPNSAsyncResult)
	go func() {
		defer close(ch)
		defer cancel()

		var out client.GetIPNSAsyncResult
		switch peer.ID(id) {
		case drs.goodPeerID:
			ie, err := ipns.Create(drs.pk1, []byte(fmt.Sprintf("RECORD FROM SERVICE %d", drs.serviceID)), 0, time.Now().Add(10*time.Hour), 100*time.Hour)
			if err != nil {
				log.Fatal(err)
			}
			ieb, err := ie.Marshal()
			if err != nil {
				log.Fatal(err)
			}

			out = client.GetIPNSAsyncResult{
				Record: ieb,
				Err:    nil,
			}
		case drs.badPeerID:
			out = client.GetIPNSAsyncResult{
				Record: nil,
				Err:    errors.New("THE ERROR"),
			}
		default:
			return
		}

		select {
		case <-ctx.Done():
			return
		case ch <- out:
		}
	}()

	return ch, nil

}

func (drs *delegatedRoutingService) PutIPNS(ctx context.Context, id []byte, record []byte) (<-chan client.PutIPNSAsyncResult, error) {
	ctx, cancel := context.WithCancel(ctx)
	ch := make(chan client.PutIPNSAsyncResult)
	go func() {
		defer close(ch)
		defer cancel()

		var out client.PutIPNSAsyncResult
		switch peer.ID(id) {
		case drs.goodPeerID:
			out = client.PutIPNSAsyncResult{}
		case drs.badPeerID:
			out = client.PutIPNSAsyncResult{
				Err: fmt.Errorf("THE ERROR %d", drs.serviceID),
			}
		default:
			return
		}

		select {
		case <-ctx.Done():
			return
		case ch <- out:
		}
	}()

	return ch, nil
}