package wasm_test

import (
	"encoding/json"
	"fmt"
	"testing"

	app2 "github.com/CosmWasm/wasmd/app"

	ibctransfertypes "github.com/cosmos/ibc-go/v7/modules/apps/transfer/types"
	ibctesting "github.com/cosmos/ibc-go/v7/testing"

	wasmvm "github.com/CosmWasm/wasmvm"
	wasmvmtypes "github.com/CosmWasm/wasmvm/types"
	sdk "github.com/cosmos/cosmos-sdk/types"
	clienttypes "github.com/cosmos/ibc-go/v7/modules/core/02-client/types"
	channeltypes "github.com/cosmos/ibc-go/v7/modules/core/04-channel/types"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	wasmibctesting "github.com/CosmWasm/wasmd/x/wasm/ibctesting"
	wasmkeeper "github.com/CosmWasm/wasmd/x/wasm/keeper"
	"github.com/CosmWasm/wasmd/x/wasm/keeper/wasmtesting"
	wasmtypes "github.com/CosmWasm/wasmd/x/wasm/types"
)

const (
	ping = "ping"
	pong = "pong"
)

var doNotTimeout = clienttypes.NewHeight(1, 1111111)

func TestPinPong(t *testing.T) {
	// custom IBC protocol example
	// scenario: given two chains,
	//           with a contract on chain A and chain B
	//           when a ibc packet comes in, the contract responds with a new packet containing
	//	         either ping or pong

	pingContract := &player{t: t, actor: ping}
	pongContract := &player{t: t, actor: pong}

	var (
		chainAOpts = []wasmkeeper.Option{
			wasmkeeper.WithWasmEngine(
				wasmtesting.NewIBCContractMockWasmer(pingContract)),
		}
		chainBOpts = []wasmkeeper.Option{wasmkeeper.WithWasmEngine(
			wasmtesting.NewIBCContractMockWasmer(pongContract),
		)}
		coordinator = wasmibctesting.NewCoordinator(t, 2, chainAOpts, chainBOpts)
		chainA      = coordinator.GetChain(wasmibctesting.GetChainID(1))
		chainB      = coordinator.GetChain(wasmibctesting.GetChainID(2))
	)
	_ = chainB.SeedNewContractInstance() // skip 1 instance so that addresses are not the same
	var (
		pingContractAddr = chainA.SeedNewContractInstance()
		pongContractAddr = chainB.SeedNewContractInstance()
	)
	require.NotEqual(t, pingContractAddr, pongContractAddr)
	coordinator.CommitBlock(chainA, chainB)

	pingContract.chain = chainA
	pingContract.contractAddr = pingContractAddr

	pongContract.chain = chainB
	pongContract.contractAddr = pongContractAddr

	var (
		sourcePortID       = wasmkeeper.PortIDForContract(pingContractAddr)
		counterpartyPortID = wasmkeeper.PortIDForContract(pongContractAddr)
	)

	path := wasmibctesting.NewPath(chainA, chainB)
	path.EndpointA.ChannelConfig = &ibctesting.ChannelConfig{
		PortID:  sourcePortID,
		Version: ibctransfertypes.Version,
		Order:   channeltypes.ORDERED,
	}
	path.EndpointB.ChannelConfig = &ibctesting.ChannelConfig{
		PortID:  counterpartyPortID,
		Version: ibctransfertypes.Version,
		Order:   channeltypes.ORDERED,
	}
	coordinator.SetupConnections(path)
	coordinator.CreateChannels(path)

	// trigger start game via execute
	const startValue uint64 = 100
	const rounds = 3
	s := startGame{
		ChannelID: path.EndpointA.ChannelID,
		Value:     startValue,
	}
	startMsg := &wasmtypes.MsgExecuteContract{
		Sender:   chainA.SenderAccount.GetAddress().String(),
		Contract: pingContractAddr.String(),
		Msg:      s.GetBytes(),
	}
	// on chain A
	_, err := path.EndpointA.Chain.SendMsgs(startMsg)
	require.NoError(t, err)

	// when some rounds are played
	for i := 1; i <= rounds; i++ {
		t.Logf("++ round: %d\n", i)

		require.Len(t, chainA.PendingSendPackets, 1)
		err := coordinator.RelayAndAckPendingPackets(path)
		require.NoError(t, err)
	}

	// then receive/response state is as expected
	assert.Equal(t, startValue+rounds, pingContract.QueryState(lastBallSentKey))
	assert.Equal(t, uint64(rounds), pingContract.QueryState(lastBallReceivedKey))
	assert.Equal(t, uint64(rounds+1), pingContract.QueryState(sentBallsCountKey))
	assert.Equal(t, uint64(rounds), pingContract.QueryState(receivedBallsCountKey))
	assert.Equal(t, uint64(rounds), pingContract.QueryState(confirmedBallsCountKey))

	assert.Equal(t, uint64(rounds), pongContract.QueryState(lastBallSentKey))
	assert.Equal(t, startValue+rounds-1, pongContract.QueryState(lastBallReceivedKey))
	assert.Equal(t, uint64(rounds), pongContract.QueryState(sentBallsCountKey))
	assert.Equal(t, uint64(rounds), pongContract.QueryState(receivedBallsCountKey))
	assert.Equal(t, uint64(rounds), pongContract.QueryState(confirmedBallsCountKey))
}

var _ wasmtesting.IBCContractCallbacks = &player{}

// player is a (mock) contract that sends and receives ibc packages
type player struct {
	t            *testing.T
	chain        *wasmibctesting.TestChain
	contractAddr sdk.AccAddress
	actor        string // either ping or pong
	execCalls    int    // number of calls to Execute method (checkTx + deliverTx)
}

// Execute starts the ping pong game
// Contracts finds all connected channels and broadcasts a ping message
func (p *player) Execute(_ wasmvm.Checksum, _ wasmvmtypes.Env, _ wasmvmtypes.MessageInfo, executeMsg []byte, store wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.Response, uint64, error) {
	p.execCalls++
	// start game
	var start startGame
	if err := json.Unmarshal(executeMsg, &start); err != nil {
		return nil, 0, err
	}

	if start.MaxValue != 0 {
		store.Set(maxValueKey, sdk.Uint64ToBigEndian(start.MaxValue))
	}
	service := NewHit(p.actor, start.Value)
	p.t.Logf("[%s] starting game with: %d: %v\n", p.actor, start.Value, service)

	p.incrementCounter(sentBallsCountKey, store)
	store.Set(lastBallSentKey, sdk.Uint64ToBigEndian(start.Value))
	return &wasmvmtypes.Response{
		Messages: []wasmvmtypes.SubMsg{
			{
				Msg: wasmvmtypes.CosmosMsg{
					IBC: &wasmvmtypes.IBCMsg{
						SendPacket: &wasmvmtypes.SendPacketMsg{
							ChannelID: start.ChannelID,
							Data:      service.GetBytes(),
							Timeout: wasmvmtypes.IBCTimeout{Block: &wasmvmtypes.IBCTimeoutBlock{
								Revision: doNotTimeout.RevisionNumber,
								Height:   doNotTimeout.RevisionHeight,
							}},
						},
					},
				},
				ReplyOn: wasmvmtypes.ReplyNever,
			},
		},
	}, 0, nil
}

// OnIBCChannelOpen ensures to accept only configured version
func (p player) IBCChannelOpen(_ wasmvm.Checksum, _ wasmvmtypes.Env, msg wasmvmtypes.IBCChannelOpenMsg, _ wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.IBC3ChannelOpenResponse, uint64, error) {
	if msg.GetChannel().Version != p.actor {
		return &wasmvmtypes.IBC3ChannelOpenResponse{}, 0, nil
	}
	return &wasmvmtypes.IBC3ChannelOpenResponse{}, 0, nil
}

// OnIBCChannelConnect persists connection endpoints
func (p player) IBCChannelConnect(_ wasmvm.Checksum, _ wasmvmtypes.Env, msg wasmvmtypes.IBCChannelConnectMsg, store wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.IBCBasicResponse, uint64, error) {
	p.storeEndpoint(store, msg.GetChannel())
	return &wasmvmtypes.IBCBasicResponse{}, 0, nil
}

// connectedChannelsModel is a simple persistence model to store endpoint addresses within the contract's store
type connectedChannelsModel struct {
	Our   wasmvmtypes.IBCEndpoint
	Their wasmvmtypes.IBCEndpoint
}

var ( // store keys
	ibcEndpointsKey = []byte("ibc-endpoints")
	maxValueKey     = []byte("max-value")
)

func (p player) storeEndpoint(store wasmvm.KVStore, channel wasmvmtypes.IBCChannel) {
	var counterparties []connectedChannelsModel
	if b := store.Get(ibcEndpointsKey); b != nil {
		require.NoError(p.t, json.Unmarshal(b, &counterparties))
	}
	counterparties = append(counterparties, connectedChannelsModel{Our: channel.Endpoint, Their: channel.CounterpartyEndpoint})
	bz, err := json.Marshal(&counterparties)
	require.NoError(p.t, err)
	store.Set(ibcEndpointsKey, bz)
}

func (p player) IBCChannelClose(_ wasmvm.Checksum, _ wasmvmtypes.Env, _ wasmvmtypes.IBCChannelCloseMsg, _ wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.IBCBasicResponse, uint64, error) {
	panic("implement me")
}

var ( // store keys
	lastBallSentKey        = []byte("lastBallSent")
	lastBallReceivedKey    = []byte("lastBallReceived")
	sentBallsCountKey      = []byte("sentBalls")
	receivedBallsCountKey  = []byte("recvBalls")
	confirmedBallsCountKey = []byte("confBalls")
)

// IBCPacketReceive receives the hit and serves a response hit via `wasmvmtypes.IBCPacket`
func (p player) IBCPacketReceive(_ wasmvm.Checksum, _ wasmvmtypes.Env, msg wasmvmtypes.IBCPacketReceiveMsg, store wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.IBCReceiveResult, uint64, error) {
	// parse received data and store
	packet := msg.Packet
	var receivedBall hit
	if err := json.Unmarshal(packet.Data, &receivedBall); err != nil {
		return &wasmvmtypes.IBCReceiveResult{
			Ok: &wasmvmtypes.IBCReceiveResponse{
				Acknowledgement: hitAcknowledgement{Error: err.Error()}.GetBytes(),
			},
			// no hit msg, we stop the game
		}, 0, nil
	}
	p.incrementCounter(receivedBallsCountKey, store)

	otherCount := receivedBall[counterParty(p.actor)]
	store.Set(lastBallReceivedKey, sdk.Uint64ToBigEndian(otherCount))

	if maxVal := store.Get(maxValueKey); maxVal != nil && otherCount > sdk.BigEndianToUint64(maxVal) {
		errMsg := fmt.Sprintf("max value exceeded: %d got %d", sdk.BigEndianToUint64(maxVal), otherCount)
		return &wasmvmtypes.IBCReceiveResult{Ok: &wasmvmtypes.IBCReceiveResponse{
			Acknowledgement: receivedBall.BuildError(errMsg).GetBytes(),
		}}, 0, nil
	}

	nextValue := p.incrementCounter(lastBallSentKey, store)
	newHit := NewHit(p.actor, nextValue)
	respHit := &wasmvmtypes.IBCMsg{SendPacket: &wasmvmtypes.SendPacketMsg{
		ChannelID: packet.Src.ChannelID,
		Data:      newHit.GetBytes(),
		Timeout: wasmvmtypes.IBCTimeout{Block: &wasmvmtypes.IBCTimeoutBlock{
			Revision: doNotTimeout.RevisionNumber,
			Height:   doNotTimeout.RevisionHeight,
		}},
	}}
	p.incrementCounter(sentBallsCountKey, store)
	p.t.Logf("[%s] received %d, returning %d: %v\n", p.actor, otherCount, nextValue, newHit)

	return &wasmvmtypes.IBCReceiveResult{
		Ok: &wasmvmtypes.IBCReceiveResponse{
			Acknowledgement: receivedBall.BuildAck().GetBytes(),
			Messages:        []wasmvmtypes.SubMsg{{Msg: wasmvmtypes.CosmosMsg{IBC: respHit}, ReplyOn: wasmvmtypes.ReplyNever}},
		},
	}, 0, nil
}

// OnIBCPacketAcknowledgement handles the packet acknowledgment frame. Stops the game on an any error
func (p player) IBCPacketAck(_ wasmvm.Checksum, _ wasmvmtypes.Env, msg wasmvmtypes.IBCPacketAckMsg, store wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.IBCBasicResponse, uint64, error) {
	// parse received data and store
	var sentBall hit
	if err := json.Unmarshal(msg.OriginalPacket.Data, &sentBall); err != nil {
		return nil, 0, err
	}

	var ack hitAcknowledgement
	if err := json.Unmarshal(msg.Acknowledgement.Data, &ack); err != nil {
		return nil, 0, err
	}
	if ack.Success != nil {
		confirmedCount := sentBall[p.actor]
		p.t.Logf("[%s] acknowledged %d: %v\n", p.actor, confirmedCount, sentBall)
	} else {
		p.t.Logf("[%s] received app layer error: %s\n", p.actor, ack.Error)
	}

	p.incrementCounter(confirmedBallsCountKey, store)
	return &wasmvmtypes.IBCBasicResponse{}, 0, nil
}

func (p player) IBCPacketTimeout(_ wasmvm.Checksum, _ wasmvmtypes.Env, _ wasmvmtypes.IBCPacketTimeoutMsg, _ wasmvm.KVStore, _ wasmvm.GoAPI, _ wasmvm.Querier, _ wasmvm.GasMeter, _ uint64, _ wasmvmtypes.UFraction) (*wasmvmtypes.IBCBasicResponse, uint64, error) {
	panic("implement me")
}

func (p player) incrementCounter(key []byte, store wasmvm.KVStore) uint64 {
	var count uint64
	bz := store.Get(key)
	if bz != nil {
		count = sdk.BigEndianToUint64(bz)
	}
	count++
	store.Set(key, sdk.Uint64ToBigEndian(count))
	return count
}

func (p player) QueryState(key []byte) uint64 {
	app := p.chain.App.(*app2.WasmApp)
	raw := app.WasmKeeper.QueryRaw(p.chain.GetContext(), p.contractAddr, key)
	return sdk.BigEndianToUint64(raw)
}

func counterParty(s string) string {
	switch s {
	case ping:
		return pong
	case pong:
		return ping
	default:
		panic(fmt.Sprintf("unsupported: %q", s))
	}
}

// hit is ibc packet payload
type hit map[string]uint64

func NewHit(player string, count uint64) hit {
	return map[string]uint64{
		player: count,
	}
}

func (h hit) GetBytes() []byte {
	b, err := json.Marshal(h)
	if err != nil {
		panic(err)
	}
	return b
}

func (h hit) String() string {
	return fmt.Sprintf("Ball %s", string(h.GetBytes()))
}

func (h hit) BuildAck() hitAcknowledgement {
	return hitAcknowledgement{Success: &h}
}

func (h hit) BuildError(errMsg string) hitAcknowledgement {
	return hitAcknowledgement{Error: errMsg}
}

// hitAcknowledgement is ibc acknowledgment payload
type hitAcknowledgement struct {
	Error   string `json:"error,omitempty"`
	Success *hit   `json:"success,omitempty"`
}

func (a hitAcknowledgement) GetBytes() []byte {
	b, err := json.Marshal(a)
	if err != nil {
		panic(err)
	}
	return b
}

// startGame is an execute message payload
type startGame struct {
	ChannelID string
	Value     uint64
	// limit above the game is aborted
	MaxValue uint64 `json:"max_value,omitempty"`
}

func (g startGame) GetBytes() wasmtypes.RawContractMessage {
	b, err := json.Marshal(g)
	if err != nil {
		panic(err)
	}
	return b
}