✨ [channel, backend/eth] Add state and sigs to RegisteredEvent

Preparation for virtual channel watching.

Signed-off-by: Matthias Geihs <[email protected]>

backend/ethereum/channel/backend.go

@@ -49,6 +49,7 @@ var (
 	abiParams     abi.Type
 	abiState      abi.Type
 	abiProgress   abi.Method
+	abiRegister   abi.Method
 )
 
 func init() {
@@ -74,6 +75,10 @@ func init() {
 	if abiProgress, ok = adj.Methods["progress"]; !ok {
 		panic("Could not find method progress in adjudicator contract.")
 	}
+
+	if abiRegister, ok = adj.Methods["register"]; !ok {
+		panic("Could not find method register in adjudicator contract.")
+	}
 }
 
 // Backend implements the interface defined in channel/Backend.go.

backend/ethereum/channel/subscription.go

@@ -16,6 +16,7 @@ package channel
 
 import (
 	"context"
+	"fmt"
 	"math/big"
 
 	"github.com/ethereum/go-ethereum"
@@ -179,7 +180,33 @@ func (a *Adjudicator) convertEvent(ctx context.Context, e *adjudicator.Adjudicat
 	base := channel.NewAdjudicatorEventBase(e.ChannelID, NewBlockTimeout(a.ContractInterface, e.Timeout), e.Version)
 	switch e.Phase {
 	case phaseDispute:
-		return &channel.RegisteredEvent{AdjudicatorEventBase: *base}, nil
+		args, err := a.fetchRegisterCallData(ctx, e.Raw.TxHash)
+		if err != nil {
+			return nil, errors.WithMessage(err, "fetching call data")
+		}
+
+		ch, ok := args.get(e.ChannelID)
+		if !ok {
+			return nil, fmt.Errorf("channel not found in calldata: %v", e.ChannelID)
+		}
+
+		var app channel.App
+		var zeroAddress common.Address
+		if ch.Params.App == zeroAddress {
+			app = channel.NoApp()
+		} else {
+			app, err = channel.Resolve(wallet.AsWalletAddr(ch.Params.App))
+			if err != nil {
+				return nil, err
+			}
+		}
+		state := FromEthState(app, &ch.State)
+
+		return &channel.RegisteredEvent{
+			AdjudicatorEventBase: *base,
+			State:                &state,
+			Sigs:                 ch.Sigs,
+		}, nil
 
 	case phaseForceExec:
 		args, err := a.fetchProgressCallData(ctx, e.Raw.TxHash)
@@ -235,3 +262,44 @@ func (a *Adjudicator) fetchProgressCallData(ctx context.Context, txHash common.H
 
 	return &args, nil
 }
+
+type registerCallData struct {
+	Channel     adjudicator.AdjudicatorSignedState
+	SubChannels []adjudicator.AdjudicatorSignedState
+}
+
+func (args *registerCallData) get(id channel.ID) (*adjudicator.AdjudicatorSignedState, bool) {
+	ch := &args.Channel
+	if ch.State.ChannelID == id {
+		return ch, true
+	}
+	for _, ch := range args.SubChannels {
+		if ch.State.ChannelID == id {
+			return &ch, true
+		}
+	}
+	return nil, false
+}
+
+func (a *Adjudicator) fetchRegisterCallData(ctx context.Context, txHash common.Hash) (*registerCallData, error) {
+	tx, _, err := a.ContractBackend.TransactionByHash(ctx, txHash)
+	if err != nil {
+		err = cherrors.CheckIsChainNotReachableError(err)
+		return nil, errors.WithMessage(err, "getting transaction")
+	}
+
+	argsData := tx.Data()[len(abiRegister.ID):]
+
+	argsI, err := abiRegister.Inputs.UnpackValues(argsData)
+	if err != nil {
+		return nil, errors.WithMessage(err, "unpacking")
+	}
+
+	var args registerCallData
+	err = abiRegister.Inputs.Copy(&args, argsI)
+	if err != nil {
+		return nil, errors.WithMessage(err, "copying into struct")
+	}
+
+	return &args, nil
+}

channel/adjudicator.go

@@ -144,6 +144,8 @@ type (
 	// registration on the blockchain.
 	RegisteredEvent struct {
 		AdjudicatorEventBase // Channel ID and Refutation phase timeout
+		State                *State
+		Sigs                 []wallet.Sig
 	}
 
 	// ConcludedEvent signals channel conclusion.