[#15] Refactor contract body for neo-go v0.91

In neo-go v0.91.0 manifest file should contain info
about all contract methods. To do that neo-go compiler
uses public function defined in contract file. This
commit splits entire Main function into smaller
independent contract methods.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

neofs_contract.go

@@ -77,7 +77,7 @@ const (
 	defaultCandidateFee   = 100 * 1_0000_0000 // 100 Fixed8 Gas
 	candidateFeeConfigKey = "InnerRingCandidateFee"
 
-	version = 2
+	version = 3
 
 	innerRingKey     = "innerring"
 	voteKey          = "ballots"
@@ -91,19 +91,22 @@ const (
 
 var (
 	configPrefix = []byte("config")
+
+	ctx storage.Context
 )
 
-func Main(op string, args []interface{}) interface{} {
+func init() {
 	// The trigger determines whether this smart-contract is being
 	// run in 'verification' or 'application' mode.
 	if runtime.GetTrigger() != runtime.Application {
-		return false
+		panic("contract has not been called in application node")
 	}
 
-	ctx := storage.GetContext()
+	ctx = storage.GetContext()
 
-	switch op {
+}
-	case "Init":
+
+func Init(args []interface{}) bool {
 	if storage.Get(ctx, innerRingKey) != nil {
 		panic("neofs: contract already deployed")
 	}
@@ -124,16 +127,17 @@ func Main(op string, args []interface{}) interface{} {
 	runtime.Log("neofs: contract initialized")
 
 	return true
-	case "InnerRingList":
-		return getInnerRingNodes(ctx, innerRingKey)
-	case "InnerRingCandidates":
-		return getInnerRingNodes(ctx, candidatesKey)
-	case "InnerRingCandidateRemove":
-		if len(args) != 1 {
-			panic("irCandidateRemove: bad arguments")
 }
 
-		key := args[0].([]byte) // inner ring candidate public key
+func InnerRingList() []node {
+	return getInnerRingNodes(ctx, innerRingKey)
+}
+
+func InnerRingCandidates() []node {
+	return getInnerRingNodes(ctx, candidatesKey)
+}
+
+func InnerRingCandidateRemove(key []byte) bool {
 	if !runtime.CheckWitness(key) {
 		panic("irCandidateRemove: you should be the owner of the public key")
 	}
@@ -153,12 +157,9 @@ func Main(op string, args []interface{}) interface{} {
 	setSerialized(ctx, candidatesKey, nodes)
 
 	return true
-	case "InnerRingCandidateAdd":
-		if len(args) != 1 {
-			panic("irCandidateAdd: bad arguments")
 }
 
-		key := args[0].([]byte) // inner ring candidate public key
+func InnerRingCandidateAdd(key []byte) bool {
 	if !runtime.CheckWitness(key) {
 		panic("irCandidateAdd: you should be the owner of the public key")
 	}
@@ -185,17 +186,18 @@ func Main(op string, args []interface{}) interface{} {
 	setSerialized(ctx, candidatesKey, list)
 
 	return true
-	case "Deposit":
+}
-		if len(args) < 2 || len(args) > 3 {
+
+func Deposit(from []byte, args []interface{}) bool {
+	if len(args) < 1 || len(args) > 2 {
 		panic("deposit: bad arguments")
 	}
 
-		from := args[0].([]byte)
 	if !runtime.CheckWitness(from) {
 		panic("deposit: you should be the owner of the wallet")
 	}
 
-		amount := args[1].(int)
+	amount := args[0].(int)
 	if amount > 0 {
 		amount = amount * 100000000
 	}
@@ -211,25 +213,21 @@ func Main(op string, args []interface{}) interface{} {
 	runtime.Log("deposit: funds have been transferred")
 
 	var rcv = from
-		if len(args) == 3 {
+	if len(args) == 2 {
-			rcv = args[2].([]byte) // todo: check if rcv value is valid
+		rcv = args[1].([]byte) // todo: check if rcv value is valid
 	}
 
 	tx := runtime.GetScriptContainer()
 	runtime.Notify("Deposit", from, amount, rcv, tx.Hash)
 
 	return true
-	case "Withdraw":
-		if len(args) != 2 {
-			panic("withdraw: bad arguments")
 }
 
-		user := args[0].([]byte)
+func Withdraw(user []byte, amount int) bool {
 	if !runtime.CheckWitness(user) {
 		panic("withdraw: you should be the owner of the wallet")
 	}
 
-		amount := args[1].(int)
 	if amount > 0 {
 		amount = amount * 100000000
 	}
@@ -238,16 +236,9 @@ func Main(op string, args []interface{}) interface{} {
 	runtime.Notify("Withdraw", user, amount, tx.Hash)
 
 	return true
-	case "Cheque":
-		if len(args) != 4 {
-			panic("cheque: bad arguments")
 }
 
-		id := args[0].([]byte)      // unique cheque id
+func Cheque(id, user []byte, amount int, lockAcc []byte) bool {
-		user := args[1].([]byte)    // GAS receiver
-		amount := args[2].(int)     // amount of GAS
-		lockAcc := args[3].([]byte) // lock account from internal balance contract
-
 	irList := getInnerRingNodes(ctx, innerRingKey)
 	threshold := len(irList)/3*2 + 1
 
@@ -285,33 +276,44 @@ func Main(op string, args []interface{}) interface{} {
 	}
 
 	return true
-	case "Bind", "Unbind":
-		if len(args) < 2 {
-			panic("binding: bad arguments")
 }
 
-		user := args[0].([]byte)
+func Bind(user []byte, keys []interface{}) bool {
 	if !runtime.CheckWitness(user) {
 		panic("binding: you should be the owner of the wallet")
 	}
 
-		var keys [][]byte
+	for i := 0; i < len(keys); i++ {
-
+		pubKey := keys[i].([]byte)
-		for i := 1; i < len(args); i++ {
+		if len(pubKey) != publicKeySize {
-			pub := args[i].([]byte)
-			if len(pub) != publicKeySize {
 			panic("binding: incorrect public key size")
 		}
-
-			keys = append(keys, pub)
 	}
 
-		runtime.Notify(op, user, keys)
+	runtime.Notify("Bind", user, keys)
 
 	return true
-	case "InnerRingUpdate":
+}
-		if len(args) < 1+minInnerRingSize {
+
-			// cheque id + inner ring public keys
+func Unbind(user []byte, keys []interface{}) bool {
+	if !runtime.CheckWitness(user) {
+		panic("unbinding: you should be the owner of the wallet")
+	}
+
+	for i := 0; i < len(keys); i++ {
+		pubKey := keys[i].([]byte)
+		if len(pubKey) != publicKeySize {
+			panic("unbinding: incorrect public key size")
+		}
+	}
+
+	runtime.Notify("Unbind", user, keys)
+
+	return true
+}
+
+func InnerRingUpdate(chequeID []byte, args [][]byte) bool {
+	if len(args) < minInnerRingSize {
 		panic("irUpdate: bad arguments")
 	}
 
@@ -323,14 +325,13 @@ func Main(op string, args []interface{}) interface{} {
 		panic("innerRingUpdate: invoked by non inner ring node")
 	}
 
-		id := args[0].([]byte)
+	c := cheque{id: chequeID}
-		c := cheque{id: id}
 
 	cashedCheques := getCashedCheques(ctx)
 
 	chequesList, ok := addCheque(cashedCheques, c)
 	if !ok {
-			panic("irUpdate: non unique id")
+		panic("irUpdate: non unique chequeID")
 	}
 
 	oldNodes := 0
@@ -339,7 +340,7 @@ func Main(op string, args []interface{}) interface{} {
 
 loop:
 	for i := 1; i < len(args); i++ {
-			key := args[i].([]byte)
+		key := args[i]
 		if len(key) != publicKeySize {
 			panic("irUpdate: invalid public key in inner ring list")
 		}
@@ -366,7 +367,7 @@ func Main(op string, args []interface{}) interface{} {
 		panic("irUpdate: inner ring change rate must not be more than 1/3 ")
 	}
 
-		hashID := crypto.SHA256(id)
+	hashID := crypto.SHA256(chequeID)
 
 	n := vote(ctx, hashID, irKey)
 	if n >= threshold {
@@ -381,12 +382,9 @@ func Main(op string, args []interface{}) interface{} {
 	}
 
 	return true
-	case "IsInnerRing":
-		if len(args) != 1 {
-			panic("isInnerRing: wrong arguments")
 }
 
-		key := args[0].([]byte)
+func IsInnerRing(key []byte) bool {
 	if len(key) != publicKeySize {
 		panic("isInnerRing: incorrect public key")
 	}
@@ -401,19 +399,13 @@ func Main(op string, args []interface{}) interface{} {
 	}
 
 	return false
-	case "Config":
-		if len(args) != 1 {
-			panic("config: bad arguments")
 }
 
-		key := args[0].([]byte)
+func Config(key []byte) interface{} {
-
 	return getConfig(ctx, key)
-	case "SetConfig":
-		if len(args) != 3 {
-			panic("setConfig: bad arguments")
 }
 
+func SetConfig(id, key, val []byte) bool {
 	// check if it is inner ring invocation
 	irList := getInnerRingNodes(ctx, innerRingKey)
 	threshold := len(irList)/3*2 + 1
@@ -424,7 +416,6 @@ func Main(op string, args []interface{}) interface{} {
 	}
 
 	// check unique id of the operation
-		id := args[0].([]byte)
 	c := cheque{id: id}
 	cashedCheques := getCashedCheques(ctx)
 
@@ -440,9 +431,6 @@ func Main(op string, args []interface{}) interface{} {
 	if n >= threshold {
 		removeVotes(ctx, hashID)
 
-			key := args[1]
-			val := args[2]
-
 		setConfig(ctx, key, val)
 		setSerialized(ctx, cashedChequesKey, chequesList)
 
@@ -451,7 +439,9 @@ func Main(op string, args []interface{}) interface{} {
 	}
 
 	return true
-	case "ListConfig":
+}
+
+func ListConfig() []record {
 	var config []record
 
 	it := storage.Find(ctx, configPrefix)
@@ -464,7 +454,9 @@ func Main(op string, args []interface{}) interface{} {
 	}
 
 	return config
-	case "InitConfig":
+}
+
+func InitConfig(args []interface{}) bool {
 	if getConfig(ctx, candidateFeeConfigKey) != nil {
 		panic("neofs: configuration already installed")
 	}
@@ -486,11 +478,10 @@ func Main(op string, args []interface{}) interface{} {
 	runtime.Log("neofs: config has been installed")
 
 	return true
-	case "Version":
-		return version
 }
 
-	panic("unknown operation")
+func Version() int {
+	return version
 }
 
 // innerRingInvoker returns public key of inner ring node that invoked contract.
@@ -552,7 +543,7 @@ func vote(ctx storage.Context, id, from []byte) int {
 	return found
 }
 
-// removeVotes clears ballots of the decision that has benn aceepted by
+// removeVotes clears ballots of the decision that has been accepted by
 // inner ring nodes.
 func removeVotes(ctx storage.Context, id []byte) {
 	var (