package powchain

import (
	"context"
	"errors"
	"math/big"
	"strings"
	"testing"

	ethereum "github.com/ethereum/go-ethereum"
	"github.com/ethereum/go-ethereum/common"
	gethTypes "github.com/ethereum/go-ethereum/core/types"
	"github.com/prysmaticlabs/prysm/shared/event"
	"github.com/prysmaticlabs/prysm/shared/testutil"
	logTest "github.com/sirupsen/logrus/hooks/test"
)

type badReader struct{}

func (b *badReader) SubscribeNewHead(ctx context.Context, ch chan<- *gethTypes.Header) (ethereum.Subscription, error) {
	return nil, errors.New("subscription has failed")
}

type goodReader struct{}

func (g *goodReader) SubscribeNewHead(ctx context.Context, ch chan<- *gethTypes.Header) (ethereum.Subscription, error) {
	return new(event.Feed).Subscribe(ch), nil
}

type badLogger struct{}

func (b *badLogger) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- gethTypes.Log) (ethereum.Subscription, error) {
	return nil, errors.New("subscription has failed")
}

type goodLogger struct{}

func (g *goodLogger) SubscribeFilterLogs(ctx context.Context, q ethereum.FilterQuery, ch chan<- gethTypes.Log) (ethereum.Subscription, error) {
	return new(event.Feed).Subscribe(ch), nil
}

func TestNewWeb3Service(t *testing.T) {
	endpoint := "http://127.0.0.1"
	ctx := context.Background()
	var err error
	if _, err = NewWeb3Service(ctx, &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	}); err == nil {
		t.Errorf("passing in an HTTP endpoint should throw an error, received nil")
	}
	endpoint = "ftp://127.0.0.1"
	if _, err = NewWeb3Service(ctx, &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	}); err == nil {
		t.Errorf("passing in a non-ws, wss, or ipc endpoint should throw an error, received nil")
	}
	endpoint = "ws://127.0.0.1"
	if _, err = NewWeb3Service(ctx, &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	}); err != nil {
		t.Errorf("passing in as ws endpoint should not throw error, received %v", err)
	}
	endpoint = "ipc://geth.ipc"
	if _, err = NewWeb3Service(ctx, &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	}); err != nil {
		t.Errorf("passing in an ipc endpoint should not throw error, received %v", err)
	}
}

func TestStart(t *testing.T) {
	hook := logTest.NewGlobal()

	endpoint := "ws://127.0.0.1"
	web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	})
	if err != nil {
		t.Fatalf("unable to setup web3 PoW chain service: %v", err)
	}

	web3Service.Start()

	msg := hook.LastEntry().Message
	want := "Could not connect to PoW chain RPC client"
	if strings.Contains(want, msg) {
		t.Errorf("incorrect log, expected %s, got %s", want, msg)
	}
	hook.Reset()
}

func TestStop(t *testing.T) {
	hook := logTest.NewGlobal()

	endpoint := "ws://127.0.0.1"
	web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	})
	if err != nil {
		t.Fatalf("unable to setup web3 PoW chain service: %v", err)
	}

	if err := web3Service.Stop(); err != nil {
		t.Fatalf("Unable to stop web3 PoW chain service: %v", err)
	}

	msg := hook.LastEntry().Message
	want := "Stopping service"
	if msg != want {
		t.Errorf("incorrect log, expected %s, got %s", want, msg)
	}

	// The context should have been canceled.
	if web3Service.ctx.Err() == nil {
		t.Error("context was not canceled")
	}
	hook.Reset()
}

func TestBadReader(t *testing.T) {
	hook := logTest.NewGlobal()
	endpoint := "ws://127.0.0.1"
	web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &badReader{},
		Logger:   &goodLogger{},
	})
	if err != nil {
		t.Fatalf("unable to setup web3 PoW chain service: %v", err)
	}
	web3Service.reader = &badReader{}
	web3Service.logger = &goodLogger{}
	web3Service.run(web3Service.ctx.Done())
	msg := hook.LastEntry().Message
	want := "Unable to subscribe to incoming PoW chain headers: subscription has failed"
	if msg != want {
		t.Errorf("incorrect log, expected %s, got %s", want, msg)
	}
	hook.Reset()
}

func TestLatestMainchainInfo(t *testing.T) {
	endpoint := "ws://127.0.0.1"
	web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	})
	if err != nil {
		t.Fatalf("unable to setup web3 PoW chain service: %v", err)
	}
	web3Service.reader = &goodReader{}
	web3Service.logger = &goodLogger{}

	exitRoutine := make(chan bool)

	go func() {
		web3Service.run(web3Service.ctx.Done())
		<-exitRoutine
	}()

	header := &gethTypes.Header{Number: big.NewInt(42)}

	web3Service.headerChan <- header
	web3Service.cancel()
	exitRoutine <- true

	if web3Service.blockNumber.Cmp(header.Number) != 0 {
		t.Errorf("block number not set, expected %v, got %v", header.Number, web3Service.blockNumber)
	}

	if web3Service.blockHash.Hex() != header.Hash().Hex() {
		t.Errorf("block hash not set, expected %v, got %v", header.Hash().Hex(), web3Service.blockHash.Hex())
	}
}

func TestBadLogger(t *testing.T) {
	hook := logTest.NewGlobal()
	endpoint := "ws://127.0.0.1"
	web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	})
	if err != nil {
		t.Fatalf("unable to setup web3 PoW chain service: %v", err)
	}
	web3Service.reader = &goodReader{}
	web3Service.logger = &badLogger{}

	web3Service.run(web3Service.ctx.Done())
	msg := hook.LastEntry().Message
	want := "Unable to query logs from VRC: subscription has failed"
	if msg != want {
		t.Errorf("incorrect log, expected %s, got %s", want, msg)
	}
	hook.Reset()
}

func TestGoodLogger(t *testing.T) {
	hook := logTest.NewGlobal()
	endpoint := "ws://127.0.0.1"
	web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
		Endpoint: endpoint,
		Pubkey:   "",
		VrcAddr:  common.Address{},
		Reader:   &goodReader{},
		Logger:   &goodLogger{},
	})
	if err != nil {
		t.Fatalf("unable to setup web3 PoW chain service: %v", err)
	}

	web3Service.pubKey = "0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
	pubkey := common.HexToHash(web3Service.pubKey)

	web3Service.reader = &goodReader{}
	web3Service.logger = &goodLogger{}

	exitRoutine := make(chan bool)

	go func() {
		web3Service.run(web3Service.ctx.Done())
		<-exitRoutine
	}()

	log := gethTypes.Log{Topics: []common.Hash{[32]byte{}, pubkey}}
	web3Service.logChan <- log
	web3Service.cancel()
	exitRoutine <- true

	lastEntry := hook.LastEntry()
	want := "Validator registered in VRC with public key"
	if lastEntry.Message != want {
		t.Errorf("incorrect log, expected %s, got %s", want, lastEntry.Message)
	}

	if lastEntry.Data["publicKey"] != web3Service.pubKey {
		t.Errorf("incorrect pubKey, expected %s, got %s", lastEntry.Data["publicKey"], web3Service.pubKey)
	}

	if !web3Service.validatorRegistered {
		t.Errorf("validatorRegistered status expected true, got %v", web3Service.validatorRegistered)
	}

	hook.Reset()
}

func TestHeaderAfterValidation(t *testing.T) {
	// User pubkeys with or without 0x should be OK.
	testPubKeys := []string{
		"0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
		"0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef",
	}

	for _, tt := range testPubKeys {
		func(pubKey string) {
			hook := logTest.NewGlobal()
			endpoint := "ws://127.0.0.1"
			web3Service, err := NewWeb3Service(context.Background(), &Web3ServiceConfig{
				Endpoint: endpoint,
				Pubkey:   "",
				VrcAddr:  common.Address{},
				Reader:   &goodReader{},
				Logger:   &goodLogger{},
			})
			if err != nil {
				t.Fatalf("unable to setup web3 PoW chain service: %v", err)
			}

			web3Service.pubKey = pubKey
			p := common.HexToHash(web3Service.pubKey)

			web3Service.reader = &goodReader{}
			web3Service.logger = &goodLogger{}

			exitRoutine := make(chan bool)

			go func() {
				web3Service.run(web3Service.ctx.Done())
				<-exitRoutine
			}()

			log := gethTypes.Log{Topics: []common.Hash{[32]byte{}, p}}
			web3Service.logChan <- log

			header := &gethTypes.Header{Number: big.NewInt(42)}
			web3Service.headerChan <- header

			web3Service.cancel()
			exitRoutine <- true

			testutil.AssertLogsContain(t, hook, "Validator registered in VRC with public key")

			if !web3Service.validatorRegistered {
				t.Errorf("validatorRegistered status expected true, got %v", web3Service.validatorRegistered)
			}

			if web3Service.blockNumber.Cmp(header.Number) != 0 {
				t.Errorf("block number not set, expected %v, got %v", header.Number, web3Service.blockNumber)
			}

			if web3Service.blockHash.Hex() != header.Hash().Hex() {
				t.Errorf("block hash not set, expected %v, got %v", header.Hash().Hex(), web3Service.blockHash.Hex())
			}
		}(tt)
	}
}