package lifecycle

import (
	"bytes"
	"context"
	"encoding/xml"
	"errors"
	"io"
	"sync"
	"testing"
	"time"

	"git.frostfs.info/TrueCloudLab/frostfs-s3-gw/api/data"
	apistatus "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/client/status"
	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/netmap"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object"
	oid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id"
	oidtest "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/object/id/test"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/pool"
	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/user"
	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/stretchr/testify/require"
	"go.uber.org/zap"
	"go.uber.org/zap/zaptest"
)

var _ UserFetcher = (*userFetcherMock)(nil)

type userFetcherMock struct {
	users map[util.Uint160]*keys.PrivateKey
}

func newUserFetcherMock(users map[util.Uint160]*keys.PrivateKey) *userFetcherMock {
	if users == nil {
		users = map[util.Uint160]*keys.PrivateKey{}
	}
	return &userFetcherMock{
		users: users,
	}
}

func (u *userFetcherMock) Users() ([]util.Uint160, error) {
	res := make([]util.Uint160, 0, len(u.users))

	for hash := range u.users {
		res = append(res, hash)
	}

	return res, nil
}

func (u *userFetcherMock) UserKey(hash util.Uint160) (*keys.PublicKey, error) {
	key, ok := u.users[hash]
	if !ok {
		return nil, errors.New("userFetcherMock: hash not found")
	}

	return key.PublicKey(), nil
}

var _ ContainerFetcher = (*containerFetcherMock)(nil)

type containerFetcherMock struct {
	containers map[util.Uint160][]cid.ID
}

func newContainerFetcherMock(containers map[util.Uint160][]cid.ID) *containerFetcherMock {
	if containers == nil {
		containers = map[util.Uint160][]cid.ID{}
	}
	return &containerFetcherMock{
		containers: containers,
	}
}

func (c *containerFetcherMock) Containers(owner user.ID) ([]cid.ID, error) {
	hash, err := owner.ScriptHash()
	if err != nil {
		return nil, err
	}

	containers, ok := c.containers[hash]
	if !ok {
		return nil, errors.New("containerFetcherMock: hash not found")
	}

	return containers, nil
}

var _ FrostFSFetcher = (*frostfsFetcherMock)(nil)

type frostfsFetcherMock struct {
	mu            sync.RWMutex
	objects       map[oid.Address]*object.Object
	epoch         uint64
	epochDuration uint64
	msPerBlock    int64
}

func newFrostFSFetcherMock() *frostfsFetcherMock {
	return &frostfsFetcherMock{
		objects:       map[oid.Address]*object.Object{},
		epoch:         1,
		epochDuration: 3600,
		msPerBlock:    1000,
	}
}

func (c *frostfsFetcherMock) setObject(addr oid.Address, obj *object.Object) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.objects[addr] = obj
}

func (c *frostfsFetcherMock) setEpoch(epoch uint64) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.epoch = epoch
}

func (c *frostfsFetcherMock) setEpochDuration(blocks uint64) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.epochDuration = blocks
}

func (c *frostfsFetcherMock) setMsPerBlock(msPerBlock int64) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.msPerBlock = msPerBlock
}

func (c *frostfsFetcherMock) GetObject(_ context.Context, addr oid.Address) (pool.ResGetObject, error) {
	c.mu.RLock()
	defer c.mu.RUnlock()

	val, ok := c.objects[addr]
	if !ok {
		return pool.ResGetObject{}, &apistatus.ObjectNotFound{}
	}

	return pool.ResGetObject{
		Header:  *val,
		Payload: &payloadReader{bytes.NewReader(val.Payload())},
	}, nil
}

type payloadReader struct {
	io.Reader
}

func (p *payloadReader) Close() error { return nil }

func (c *frostfsFetcherMock) NetworkInfo(context.Context) (*netmap.NetworkInfo, error) {
	c.mu.RLock()
	defer c.mu.RUnlock()

	var ni netmap.NetworkInfo
	ni.SetCurrentEpoch(c.epoch)
	ni.SetEpochDuration(c.epochDuration)
	ni.SetMsPerBlock(c.msPerBlock)
	return &ni, nil
}

func (c *frostfsFetcherMock) DeleteObject(_ context.Context, addr oid.Address) error {
	c.mu.Lock()
	defer c.mu.Unlock()

	if _, ok := c.objects[addr]; !ok {
		return &apistatus.ObjectNotFound{}
	}

	delete(c.objects, addr)
	return nil
}

var _ CredentialSource = (*credentialSourceMock)(nil)

type credentialSourceMock struct {
	users map[util.Uint160]*keys.PrivateKey
}

func newCredentialSourceMock(users map[util.Uint160]*keys.PrivateKey) *credentialSourceMock {
	if users == nil {
		users = map[util.Uint160]*keys.PrivateKey{}
	}
	return &credentialSourceMock{
		users: users,
	}
}

func (c *credentialSourceMock) Credentials(_ context.Context, pk *keys.PublicKey) (*keys.PrivateKey, error) {
	key, ok := c.users[pk.GetScriptHash()]
	if !ok {
		return nil, errors.New("credentialSourceMock: hash not found")
	}

	return key, nil
}

var _ TreeFetcher = (*treeFetcherMock)(nil)

type treeFetcherMock struct {
	configurations map[cid.ID]oid.ID
}

func newTreeFetcherMock(configs map[cid.ID]oid.ID) *treeFetcherMock {
	if configs == nil {
		configs = map[cid.ID]oid.ID{}
	}
	return &treeFetcherMock{
		configurations: configs,
	}
}

func (t *treeFetcherMock) GetBucketLifecycleConfiguration(_ context.Context, bktInfo *data.BucketInfo) (oid.ID, error) {
	val, ok := t.configurations[bktInfo.CID]
	if !ok {
		return oid.ID{}, errors.New("treeFetcherMock: hash not found")
	}

	return val, nil
}

var _ Settings = (*settingsMock)(nil)

type settingsMock struct{}

func (s *settingsMock) ServicesKeys() keys.PublicKeys {
	return nil
}

func TestFetcherBase(t *testing.T) {
	ctx := context.Background()
	log := zaptest.NewLogger(t)

	key, err := keys.NewPrivateKey()
	require.NoError(t, err)

	mocks, err := initFetcherMocks(2, 1)
	require.NoError(t, err)

	epochCh := make(chan uint64)
	go func() {
		epochCh <- 1
		close(epochCh)
	}()

	cfg := Config{
		UserFetcher:       mocks.userFetcher,
		ContainerFetcher:  mocks.containerFetcher,
		FrostFSFetcher:    mocks.configurationFetcher,
		CredentialSource:  mocks.credentialSource,
		TreeFetcher:       mocks.treeFetcher,
		Settings:          &settingsMock{},
		CurrentLifecycler: key,
		Logger:            log,
		EpochChannel:      epochCh,
	}

	f := NewJobProvider(ctx, cfg)

	var res []Job
	for job := range f.Jobs() {
		res = append(res, job)
	}

	require.Len(t, res, 2)
}

func TestFetcherCancel(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	log := zaptest.NewLogger(t)

	key, err := keys.NewPrivateKey()
	require.NoError(t, err)

	mocks, err := initFetcherMocks(1, 1)
	require.NoError(t, err)

	epochCh := make(chan uint64)
	go func() {
		epochCh <- 1
		epochCh <- 2
		close(epochCh)
	}()

	cfg := Config{
		UserFetcher:       mocks.userFetcher,
		ContainerFetcher:  mocks.containerFetcher,
		FrostFSFetcher:    mocks.configurationFetcher,
		CredentialSource:  mocks.credentialSource,
		TreeFetcher:       mocks.treeFetcher,
		Settings:          &settingsMock{},
		CurrentLifecycler: key,
		Logger:            log,
		EpochChannel:      epochCh,
	}

	f := NewJobProvider(ctx, cfg)

	var res []Job
	for job := range f.Jobs() {
		res = append(res, job)
	}

	require.Len(t, res, 1)
}

func TestFetcherCleanBuffer(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	log := zaptest.NewLogger(t)

	key, err := keys.NewPrivateKey()
	require.NoError(t, err)

	mocks, err := initFetcherMocks(1, 10)
	require.NoError(t, err)

	epochCh := make(chan uint64)
	f := newJobProvider(ctx, mocks, epochCh, key, log, 11)

	epochCh <- 1

	for len(f.Jobs()) != 10 { // wait jobs buffer be filled by first epoch works
		time.Sleep(100 * time.Millisecond)
	}

	mocks, err = initFetcherMocks(1, 11)
	require.NoError(t, err)
	updateFetcherMocks(f, mocks)

	epochCh <- 2
	close(epochCh)

	for len(f.Jobs()) != 11 { // wait jobs buffer be filled by second epoch works
		time.Sleep(100 * time.Millisecond)
	}

	for job := range f.Jobs() {
		require.Equal(t, uint64(2), job.Epoch, "not all old epoch job is cleaned from buffer")
	}
}

func newJobProvider(ctx context.Context, mocks *fetchersMock, epochCh <-chan uint64, key *keys.PrivateKey, log *zap.Logger, bufferSize int) *JobProvider {
	cfg := Config{
		UserFetcher:       mocks.userFetcher,
		ContainerFetcher:  mocks.containerFetcher,
		FrostFSFetcher:    mocks.configurationFetcher,
		CredentialSource:  mocks.credentialSource,
		TreeFetcher:       mocks.treeFetcher,
		Settings:          &settingsMock{},
		CurrentLifecycler: key,
		Logger:            log,
		EpochChannel:      epochCh,
		BufferSize:        bufferSize,
	}

	return NewJobProvider(ctx, cfg)
}

func updateFetcherMocks(f *JobProvider, mocks *fetchersMock) {
	f.userFetcher = mocks.userFetcher
	f.containerFetcher = mocks.containerFetcher
	f.frostfsFetcher = mocks.configurationFetcher
	f.credentialSource = mocks.credentialSource
	f.treeFetcher = mocks.treeFetcher
}

type fetchersMock struct {
	userFetcher          *userFetcherMock
	containerFetcher     *containerFetcherMock
	configurationFetcher *frostfsFetcherMock
	credentialSource     *credentialSourceMock
	treeFetcher          *treeFetcherMock
}

func initFetcherMocks(users, containers int) (*fetchersMock, error) {
	usersMap, err := generateUsersMap(users)
	if err != nil {
		return nil, err
	}

	ffsFetcher := newFrostFSFetcherMock()
	cnrsMap := make(map[util.Uint160][]cid.ID)
	treeMap := make(map[cid.ID]oid.ID)
	for hash := range usersMap {
		for i := 0; i < containers; i++ {
			addr := oidtest.Address()
			cnrsMap[hash] = append(cnrsMap[hash], addr.Container())
			treeMap[addr.Container()] = addr.Object()

			lc := &data.LifecycleConfiguration{Rules: []data.LifecycleRule{{ID: addr.EncodeToString()}}}
			raw, err := xml.Marshal(lc)
			if err != nil {
				return nil, err
			}

			obj := object.New()
			obj.SetPayload(raw)
			obj.SetContainerID(addr.Container())
			obj.SetID(addr.Object())
			ffsFetcher.objects[addr] = obj
		}
	}

	return &fetchersMock{
		userFetcher:          newUserFetcherMock(usersMap),
		containerFetcher:     newContainerFetcherMock(cnrsMap),
		configurationFetcher: ffsFetcher,
		credentialSource:     newCredentialSourceMock(usersMap),
		treeFetcher:          newTreeFetcherMock(treeMap),
	}, nil
}

func generateKeys(n int) ([]*keys.PrivateKey, error) {
	var err error
	res := make([]*keys.PrivateKey, n)

	for i := 0; i < n; i++ {
		if res[i], err = keys.NewPrivateKey(); err != nil {
			return nil, err
		}
	}

	return res, nil
}

func generateUsersMap(n int) (map[util.Uint160]*keys.PrivateKey, error) {
	res := make(map[util.Uint160]*keys.PrivateKey, n)

	userKeys, err := generateKeys(n)
	if err != nil {
		return nil, err
	}

	for _, key := range userKeys {
		res[key.GetScriptHash()] = key
	}

	return res, nil
}