package searchsvc

import (
	"context"
	"crypto/rand"
	"crypto/sha256"
	"errors"
	"fmt"
	"strconv"
	"testing"

	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/session"
	clientcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/client"
	containerCore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/container"
	netmapcore "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/netmap"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/network"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object/util"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/object_manager/placement"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger/test"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
	cidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id/test"
	frostfsecdsa "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/crypto/ecdsa"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
	oidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id/test"
	sessionsdk "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/session"
	"github.com/google/uuid"
	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
	"github.com/stretchr/testify/require"
)

type idsErr struct {
	ids []oid.ID
	err error
}

type testStorage struct {
	items map[string]idsErr
}

type testTraverserGenerator struct {
	c container.Container
	b map[uint64]placement.Builder
}

type testPlacementBuilder struct {
	vectors map[string][][]netmap.NodeInfo
}

type testClientCache struct {
	clients map[string]*testStorage
}

type simpleIDWriter struct {
	ids []oid.ID
}

type testEpochReceiver uint64

func (e testEpochReceiver) Epoch() (uint64, error) {
	return uint64(e), nil
}

type errIDWriter struct {
	err error
}

func (e errIDWriter) WriteIDs(ids []oid.ID) error {
	return e.err
}

func (s *simpleIDWriter) WriteIDs(ids []oid.ID) error {
	s.ids = append(s.ids, ids...)
	return nil
}

func newTestStorage() *testStorage {
	return &testStorage{
		items: make(map[string]idsErr),
	}
}

func (g *testTraverserGenerator) GenerateTraverser(_ cid.ID, _ *oid.ID, epoch uint64) (*placement.Traverser, *containerCore.Container, error) {
	t, err := placement.NewTraverser(
		placement.ForContainer(g.c),
		placement.UseBuilder(g.b[epoch]),
		placement.WithoutSuccessTracking(),
	)
	return t, &containerCore.Container{Value: g.c}, err
}

func (p *testPlacementBuilder) BuildPlacement(cnr cid.ID, obj *oid.ID, _ netmap.PlacementPolicy) ([][]netmap.NodeInfo, error) {
	var addr oid.Address
	addr.SetContainer(cnr)

	if obj != nil {
		addr.SetObject(*obj)
	}

	vs, ok := p.vectors[addr.EncodeToString()]
	if !ok {
		return nil, errors.New("vectors for address not found")
	}

	res := make([][]netmap.NodeInfo, len(vs))
	copy(res, vs)

	return res, nil
}

func (c *testClientCache) get(info clientcore.NodeInfo) (searchClient, error) {
	v, ok := c.clients[network.StringifyGroup(info.AddressGroup())]
	if !ok {
		return nil, errors.New("could not construct client")
	}

	return v, nil
}

func (s *testStorage) search(_ context.Context, exec *execCtx) ([]oid.ID, error) {
	v, ok := s.items[exec.containerID().EncodeToString()]
	if !ok {
		return nil, nil
	}

	return v.ids, v.err
}

func (c *testStorage) searchObjects(_ context.Context, exec *execCtx, _ clientcore.NodeInfo) ([]oid.ID, error) {
	v, ok := c.items[exec.containerID().EncodeToString()]
	if !ok {
		return nil, nil
	}

	return v.ids, v.err
}

func (c *testStorage) addResult(addr cid.ID, ids []oid.ID, err error) {
	c.items[addr.EncodeToString()] = idsErr{
		ids: ids,
		err: err,
	}
}

func testSHA256() (cs [sha256.Size]byte) {
	rand.Read(cs[:])
	return cs
}

func generateIDs(num int) []oid.ID {
	res := make([]oid.ID, num)

	for i := range num {
		res[i].SetSHA256(testSHA256())
	}

	return res
}

func TestGetLocalOnly(t *testing.T) {
	ctx := context.Background()

	newSvc := func(storage *testStorage) *Service {
		svc := &Service{cfg: new(cfg)}
		svc.log = test.NewLogger(t)
		svc.localStorage = storage

		return svc
	}

	newPrm := func(cnr cid.ID, w IDListWriter) Prm {
		p := Prm{}
		p.WithContainerID(cnr)
		p.SetWriter(w)
		p.common = new(util.CommonPrm).WithLocalOnly(true)

		return p
	}

	t.Run("OK", func(t *testing.T) {
		storage := newTestStorage()
		svc := newSvc(storage)

		cnr := cidtest.ID()
		ids := generateIDs(10)
		storage.addResult(cnr, ids, nil)

		w := new(simpleIDWriter)
		p := newPrm(cnr, w)

		err := svc.Search(ctx, p)
		require.NoError(t, err)
		require.Equal(t, ids, w.ids)
	})

	t.Run("FAIL", func(t *testing.T) {
		storage := newTestStorage()
		svc := newSvc(storage)

		cnr := cidtest.ID()
		testErr := errors.New("any error")
		storage.addResult(cnr, nil, testErr)

		w := new(simpleIDWriter)
		p := newPrm(cnr, w)

		err := svc.Search(ctx, p)
		require.ErrorIs(t, err, testErr)
	})
	t.Run("FAIL while writing ID", func(t *testing.T) {
		storage := newTestStorage()
		svc := newSvc(storage)

		cnr := cidtest.ID()
		storage.addResult(cnr, []oid.ID{oidtest.ID()}, nil)

		testErr := errors.New("any error")
		w := errIDWriter{testErr}
		p := newPrm(cnr, w)

		err := svc.Search(ctx, p)
		require.ErrorIs(t, err, testErr)
	})
}

func testNodeMatrix(t testing.TB, dim []int) ([][]netmap.NodeInfo, [][]string) {
	mNodes := make([][]netmap.NodeInfo, len(dim))
	mAddr := make([][]string, len(dim))

	for i := range dim {
		ns := make([]netmap.NodeInfo, dim[i])
		as := make([]string, dim[i])

		for j := range dim[i] {
			a := fmt.Sprintf("/ip4/192.168.0.%s/tcp/%s",
				strconv.Itoa(i),
				strconv.Itoa(60000+j),
			)

			var ni netmap.NodeInfo
			ni.SetNetworkEndpoints(a)

			var na network.AddressGroup

			err := na.FromIterator(netmapcore.Node(ni))
			require.NoError(t, err)

			as[j] = network.StringifyGroup(na)

			ns[j] = ni
		}

		mNodes[i] = ns
		mAddr[i] = as
	}

	return mNodes, mAddr
}

func TestGetRemoteSmall(t *testing.T) {
	ctx := context.Background()

	placementDim := []int{2}

	rs := make([]netmap.ReplicaDescriptor, len(placementDim))
	for i := range placementDim {
		rs[i].SetNumberOfObjects(uint32(placementDim[i]))
	}

	var pp netmap.PlacementPolicy
	pp.AddReplicas(rs...)

	var cnr container.Container
	cnr.SetPlacementPolicy(pp)

	var id cid.ID
	container.CalculateID(&id, cnr)

	newSvc := func(b *testPlacementBuilder, c *testClientCache) *Service {
		svc := &Service{cfg: new(cfg)}
		svc.log = test.NewLogger(t)
		svc.localStorage = newTestStorage()

		const curEpoch = 13

		svc.traverserGenerator = &testTraverserGenerator{
			c: cnr,
			b: map[uint64]placement.Builder{
				curEpoch: b,
			},
		}
		svc.clientConstructor = c
		svc.currentEpochReceiver = testEpochReceiver(curEpoch)

		return svc
	}

	newPrm := func(id cid.ID, w IDListWriter) Prm {
		p := Prm{}
		p.WithContainerID(id)
		p.SetWriter(w)
		p.common = new(util.CommonPrm).WithLocalOnly(false)

		return p
	}

	var addr oid.Address
	addr.SetContainer(id)

	ns, as := testNodeMatrix(t, placementDim)

	builder := &testPlacementBuilder{
		vectors: map[string][][]netmap.NodeInfo{
			addr.EncodeToString(): ns,
		},
	}

	c1 := newTestStorage()
	ids1 := generateIDs(10)

	c2 := newTestStorage()
	ids2 := generateIDs(10)

	svc := newSvc(builder, &testClientCache{
		clients: map[string]*testStorage{
			as[0][0]: c1,
			as[0][1]: c2,
		},
	})

	t.Run("OK", func(t *testing.T) {
		c1.addResult(id, ids1, nil)
		c2.addResult(id, ids2, nil)

		w := new(simpleIDWriter)

		p := newPrm(id, w)

		err := svc.Search(ctx, p)
		require.NoError(t, err)
		require.Len(t, w.ids, len(ids1)+len(ids2))

		for _, id := range append(ids1, ids2...) {
			require.Contains(t, w.ids, id)
		}
	})
	t.Run("non-local fail is not a FAIL", func(t *testing.T) {
		testErr := errors.New("opaque")

		c1.addResult(id, ids1, nil)
		c2.addResult(id, nil, testErr)

		w := new(simpleIDWriter)
		p := newPrm(id, w)

		err := svc.Search(ctx, p)
		require.NoError(t, err)
		require.Equal(t, ids1, w.ids)
	})
	t.Run("client init fail is not a FAIL", func(t *testing.T) {
		svc := newSvc(builder, &testClientCache{
			clients: map[string]*testStorage{
				as[0][0]: c1,
			},
		})
		c1.addResult(id, ids1, nil)
		c2.addResult(id, ids2, nil)

		w := new(simpleIDWriter)
		p := newPrm(id, w)

		err := svc.Search(ctx, p)
		require.NoError(t, err)
		require.Equal(t, ids1, w.ids)
	})
	t.Run("context is respected", func(t *testing.T) {
		c1.addResult(id, ids1, nil)
		c2.addResult(id, ids2, nil)

		w := new(simpleIDWriter)
		p := newPrm(id, w)

		ctx, cancel := context.WithCancel(context.Background())
		cancel()

		err := svc.Search(ctx, p)
		require.NoError(t, err)
		require.Empty(t, w.ids)
	})
}

func TestGetFromPastEpoch(t *testing.T) {
	ctx := context.Background()

	placementDim := []int{2, 2}

	rs := make([]netmap.ReplicaDescriptor, len(placementDim))

	for i := range placementDim {
		rs[i].SetNumberOfObjects(uint32(placementDim[i]))
	}

	var pp netmap.PlacementPolicy
	pp.AddReplicas(rs...)

	var cnr container.Container
	cnr.SetPlacementPolicy(pp)

	var idCnr cid.ID
	container.CalculateID(&idCnr, cnr)

	var addr oid.Address
	addr.SetContainer(idCnr)

	ns, as := testNodeMatrix(t, placementDim)

	c11 := newTestStorage()
	ids11 := generateIDs(10)
	c11.addResult(idCnr, ids11, nil)

	c12 := newTestStorage()
	ids12 := generateIDs(10)
	c12.addResult(idCnr, ids12, nil)

	c21 := newTestStorage()
	ids21 := generateIDs(10)
	c21.addResult(idCnr, ids21, nil)

	c22 := newTestStorage()
	ids22 := generateIDs(10)
	c22.addResult(idCnr, ids22, nil)

	svc := &Service{cfg: new(cfg)}
	svc.log = test.NewLogger(t)
	svc.localStorage = newTestStorage()

	const curEpoch = 13

	svc.traverserGenerator = &testTraverserGenerator{
		c: cnr,
		b: map[uint64]placement.Builder{
			curEpoch: &testPlacementBuilder{
				vectors: map[string][][]netmap.NodeInfo{
					addr.EncodeToString(): ns[:1],
				},
			},
			curEpoch - 1: &testPlacementBuilder{
				vectors: map[string][][]netmap.NodeInfo{
					addr.EncodeToString(): ns[1:],
				},
			},
		},
	}

	svc.clientConstructor = &testClientCache{
		clients: map[string]*testStorage{
			as[0][0]: c11,
			as[0][1]: c12,
			as[1][0]: c21,
			as[1][1]: c22,
		},
	}

	svc.currentEpochReceiver = testEpochReceiver(curEpoch)

	w := new(simpleIDWriter)

	p := Prm{}
	p.WithContainerID(idCnr)
	p.SetWriter(w)

	commonPrm := new(util.CommonPrm)
	p.SetCommonParameters(commonPrm)

	assertContains := func(idsList ...[]oid.ID) {
		var sz int

		for _, ids := range idsList {
			sz += len(ids)

			for _, id := range ids {
				require.Contains(t, w.ids, id)
			}
		}

		require.Len(t, w.ids, sz)
	}

	err := svc.Search(ctx, p)
	require.NoError(t, err)
	assertContains(ids11, ids12)

	commonPrm.SetNetmapLookupDepth(1)
	w = new(simpleIDWriter)
	p.SetWriter(w)

	err = svc.Search(ctx, p)
	require.NoError(t, err)
	assertContains(ids11, ids12, ids21, ids22)
}

func TestGetWithSessionToken(t *testing.T) {
	ctx := context.Background()

	placementDim := []int{2}

	rs := make([]netmap.ReplicaDescriptor, len(placementDim))
	for i := range placementDim {
		rs[i].SetNumberOfObjects(uint32(placementDim[i]))
	}

	var pp netmap.PlacementPolicy
	pp.AddReplicas(rs...)

	var cnr container.Container
	cnr.SetPlacementPolicy(pp)

	var id cid.ID
	container.CalculateID(&id, cnr)

	var addr oid.Address
	addr.SetContainer(id)

	ns, as := testNodeMatrix(t, placementDim)

	builder := &testPlacementBuilder{
		vectors: map[string][][]netmap.NodeInfo{
			addr.EncodeToString(): ns,
		},
	}

	localStorage := newTestStorage()
	localIDs := generateIDs(10)
	localStorage.addResult(id, localIDs, nil)

	c1 := newTestStorage()
	ids1 := generateIDs(10)
	c1.addResult(id, ids1, nil)

	c2 := newTestStorage()
	ids2 := generateIDs(10)
	c2.addResult(id, ids2, nil)

	w := new(simpleIDWriter)

	svc := &Service{cfg: new(cfg)}
	svc.log = test.NewLogger(t)
	svc.localStorage = localStorage

	const curEpoch = 13

	svc.traverserGenerator = &testTraverserGenerator{
		c: cnr,
		b: map[uint64]placement.Builder{
			curEpoch: builder,
		},
	}
	svc.clientConstructor = &testClientCache{
		clients: map[string]*testStorage{
			as[0][0]: c1,
			as[0][1]: c2,
		},
	}

	svc.currentEpochReceiver = testEpochReceiver(curEpoch)

	metaStub := &metaStub{
		TTL:              5,
		LimitByObjectIDs: append(append(localIDs[:5], ids1[:5]...), ids2[:5]...),
		T:                t,
		Exp:              20,
		ContainerID:      id,
	}

	p := Prm{}
	p.WithContainerID(id)
	p.SetWriter(w)
	var err error
	p.common, err = util.CommonPrmFromV2(metaStub)
	require.NoError(t, err)

	err = svc.Search(ctx, p)
	require.NoError(t, err)
	require.Len(t, w.ids, 15)

	for _, id := range metaStub.LimitByObjectIDs {
		require.Contains(t, w.ids, id)
	}
}

type metaStub struct {
	TTL              uint32
	Exp              uint64
	LimitByObjectIDs []oid.ID
	T                *testing.T
	ContainerID      cid.ID
}

func (m *metaStub) GetMetaHeader() *session.RequestMetaHeader {
	var result session.RequestMetaHeader
	result.SetTTL(m.TTL)

	tokenObj := new(sessionsdk.Object)
	tokenObj.ForVerb(sessionsdk.VerbObjectSearch)
	tokenObj.LimitByObjects(m.LimitByObjectIDs...)
	tokenObj.SetID(uuid.New())
	tokenObj.SetExp(m.Exp)
	tokenObj.BindContainer(m.ContainerID)

	pubKey := &frostfsecdsa.PublicKey{}

	tokenObj.SetAuthKey(pubKey)

	priv, err := keys.NewPrivateKey()
	require.NoError(m.T, err)

	require.NoError(m.T, tokenObj.Sign(priv.PrivateKey))

	var token session.Token
	tokenObj.WriteToV2(&token)

	result.SetSessionToken(&token)

	return &result
}