Merge pull request #1975 from 0chain/1922_service_fee

Added ZCN Service Fee

code/go/0chain.net/smartcontract/zcnsc/context_helpers_test.go

@@ -87,6 +87,7 @@ func MakeMockStateContext() *mockStateContext {
 	// Transfers
 
 	var transfers []*state.Transfer
+	var mints []*state.Mint
 
 	// EventsDB
 	events = make(map[string]*AuthorizerNode, 100)
@@ -188,7 +189,13 @@ func MakeMockStateContext() *mockStateContext {
 			return nil
 		})
 
-	ctx.On("AddMint", mock.AnythingOfType("*state.Mint")).Return(nil)
+	ctx.On("AddMint", mock.AnythingOfType("*state.Mint")).Return(func(m *state.Mint) error {
+		mints = append(mints, m)
+		return nil
+	})
+	ctx.On("GetMints").Return(func() []*state.Mint {
+		return mints
+	})
 
 	// EventsDB
 

code/go/0chain.net/smartcontract/zcnsc/mint.go

@@ -8,6 +8,7 @@ import (
 	"0chain.net/chaincore/state"
 	"0chain.net/chaincore/transaction"
 	"0chain.net/core/common"
+	"github.com/0chain/common/core/currency"
 	"github.com/0chain/common/core/logging"
 	"github.com/pkg/errors"
 	"go.uber.org/zap"
@@ -19,13 +20,11 @@ func (zcn *ZCNSmartContract) Mint(trans *transaction.Transaction, inputData []by
 		code = "failed to mint"
 	)
 
-	var (
-		info = fmt.Sprintf(
-			"transaction hash %s, clientID: %s, payload: %s",
-			trans.Hash,
-			trans.ClientID,
-			string(inputData),
-		)
+	info := fmt.Sprintf(
+		"transaction hash %s, clientID: %s, payload: %s",
+		trans.Hash,
+		trans.ClientID,
+		string(inputData),
 	)
 
 	gn, err := GetGlobalNode(ctx)
@@ -114,14 +113,47 @@ func (zcn *ZCNSmartContract) Mint(trans *transaction.Transaction, inputData []by
 	// record the global nonce from solidity smart contract
 	gn.WZCNNonceMinted[payload.Nonce] = true
 
+	var (
+		amount currency.Coin
+		n      currency.Coin
+		share  currency.Coin
+	)
+	share, _, err = currency.DistributeCoin(gn.ZCNSConfig.MaxFee, int64(len(payload.Signatures)))
+	if err != nil {
+		err = errors.Wrap(err, fmt.Sprintf("%s, DistributeCoin operation, %s", code, info))
+		return
+	}
+	n, err = currency.Int64ToCoin(int64(len(payload.Signatures)))
+	if err != nil {
+		err = errors.Wrap(err, fmt.Sprintf("%s, convert len signatures to coin, %s", code, info))
+		return
+	}
+	amount, err = currency.MinusCoin(payload.Amount, share*n)
+	if err != nil {
+		err = errors.Wrap(err, fmt.Sprintf("%s, payload.Amount - share * len(signatures), %s", code, info))
+		return
+	}
+	payload.Amount = amount
+	for _, sig := range payload.Signatures {
+		err = ctx.AddMint(&state.Mint{
+			Minter:     gn.ID,
+			ToClientID: sig.ID,
+			Amount:     share,
+		})
+		if err != nil {
+			err = errors.Wrap(err, fmt.Sprintf("%s, AddMint for authorizers, %s", code, info))
+			return
+		}
+	}
+
 	// mint the tokens
 	err = ctx.AddMint(&state.Mint{
 		Minter:     gn.ID,
 		ToClientID: trans.ClientID,
 		Amount:     payload.Amount,
 	})
 	if err != nil {
-		err = errors.Wrap(err, fmt.Sprintf("%s, add mint operation, %s", code, info))
+		err = errors.Wrap(err, fmt.Sprintf("%s, Add mint operation, %s", code, info))
 		return
 	}
 

code/go/0chain.net/smartcontract/zcnsc/mint_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	. "0chain.net/smartcontract/zcnsc"
+	"github.com/0chain/common/core/currency"
 	"github.com/0chain/common/core/logging"
 	"github.com/stretchr/testify/require"
 	"go.uber.org/zap"
@@ -66,6 +67,43 @@ func Test_FuzzyMintTest(t *testing.T) {
 	}
 }
 
+func Test_MaxFeeMint(t *testing.T) {
+	const maxFee = 10
+	ctx := MakeMockStateContext()
+	ctx.globalNode.ZCNSConfig.MaxFee = maxFee
+	contract := CreateZCNSmartContract()
+	payload, err := CreateMintPayload(ctx, defaultClient)
+	require.NoError(t, err)
+
+	transaction, err := CreateTransaction(defaultClient, "mint", payload.Encode(), ctx)
+	require.NoError(t, err)
+
+	response, err := contract.Mint(transaction, payload.Encode(), ctx)
+	require.NoError(t, err, "Testing authorizer: '%s'", defaultClient)
+	require.NotNil(t, response)
+	require.NotEmpty(t, response)
+
+	mm := ctx.GetMints()
+	require.Equal(t, len(mm), len(authorizersID)+1)
+	expectedShare, _, err := currency.DistributeCoin(maxFee, int64(len(authorizersID)))
+	require.NoError(t, err)
+	for i := 0; i < 3; i++ {
+		require.Equal(t, mm[i].ToClientID, authorizersID[i])
+		require.Equal(t, mm[i].Amount, expectedShare)
+	}
+
+	rp := &MintPayload{}
+	require.NoError(t, rp.Decode([]byte(response)))
+	require.Equal(t, payload.ReceivingClientID, rp.ReceivingClientID)
+	sz, err := currency.Int64ToCoin(int64(len(authorizersID)))
+	require.NoError(t, err)
+	totalShare, err := currency.MultCoin(expectedShare, sz)
+	require.NoError(t, err)
+	expectedAmount, err := currency.MinusCoin(payload.Amount, totalShare)
+	require.NoError(t, err)
+	require.Equal(t, rp.Amount, expectedAmount)
+}
+
 func Test_EmptySignaturesShouldFail(t *testing.T) {
 	ctx := MakeMockStateContext()
 	contract := CreateZCNSmartContract()