From 44334486456c6881e86680997d40bf39319d783b Mon Sep 17 00:00:00 2001
From: Alex Vanin <alexey@nspcc.ru>
Date: Tue, 2 Feb 2021 16:45:13 +0300
Subject: [PATCH] [#365] settlement/basic: Check amount of collected assets

Some transfers from container owners into bank account may
fail due to lack of assets, so we have to deal with remaining
amount of assets in banking account.

Signed-off-by: Alex Vanin <alexey@nspcc.ru>
---
 .../processors/settlement/basic/collect.go         |  2 --
 .../processors/settlement/basic/context.go         |  9 +++++++++
 .../processors/settlement/basic/distribute.go      | 14 ++++++++++++++
 pkg/innerring/settlement.go                        |  5 +++++
 4 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/pkg/innerring/processors/settlement/basic/collect.go b/pkg/innerring/processors/settlement/basic/collect.go
index ad205afde..2c978c9c2 100644
--- a/pkg/innerring/processors/settlement/basic/collect.go
+++ b/pkg/innerring/processors/settlement/basic/collect.go
@@ -18,8 +18,6 @@ func (inc *IncomeSettlementContext) Collect() {
 	inc.mu.Lock()
 	defer inc.mu.Unlock()
 
-	// todo: save state of bank wallet
-
 	cachedRate, err := inc.rate.BasicRate()
 	if err != nil {
 		inc.log.Error("can't get basic income rate",
diff --git a/pkg/innerring/processors/settlement/basic/context.go b/pkg/innerring/processors/settlement/basic/context.go
index 1b46fbe44..6528fed3c 100644
--- a/pkg/innerring/processors/settlement/basic/context.go
+++ b/pkg/innerring/processors/settlement/basic/context.go
@@ -1,6 +1,7 @@
 package basic
 
 import (
+	"math/big"
 	"sync"
 
 	"github.com/mr-tron/base58"
@@ -21,6 +22,11 @@ type (
 		BasicRate() (uint64, error)
 	}
 
+	// BalanceFetcher uses NEP-17 compatible balance contract
+	BalanceFetcher interface {
+		Balance(id *owner.ID) (*big.Int, error)
+	}
+
 	IncomeSettlementContext struct {
 		mu sync.Mutex // lock to prevent collection and distribution in the same time
 
@@ -29,6 +35,7 @@ type (
 
 		rate        RateFetcher
 		estimations EstimationFetcher
+		balances    BalanceFetcher
 		container   common.ContainerStorage
 		placement   common.PlacementCalculator
 		exchange    common.Exchanger
@@ -42,6 +49,7 @@ type (
 		Epoch       uint64
 		Rate        RateFetcher
 		Estimations EstimationFetcher
+		Balances    BalanceFetcher
 		Container   common.ContainerStorage
 		Placement   common.PlacementCalculator
 		Exchange    common.Exchanger
@@ -59,6 +67,7 @@ func NewIncomeSettlementContext(p *IncomeSettlementContextPrms) (*IncomeSettleme
 		epoch:       p.Epoch,
 		rate:        p.Rate,
 		estimations: p.Estimations,
+		balances:    p.Balances,
 		container:   p.Container,
 		placement:   p.Placement,
 		exchange:    p.Exchange,
diff --git a/pkg/innerring/processors/settlement/basic/distribute.go b/pkg/innerring/processors/settlement/basic/distribute.go
index 3ec5e9797..70eb13d2f 100644
--- a/pkg/innerring/processors/settlement/basic/distribute.go
+++ b/pkg/innerring/processors/settlement/basic/distribute.go
@@ -1,6 +1,20 @@
 package basic
 
+import (
+	"go.uber.org/zap"
+)
+
 func (inc *IncomeSettlementContext) Distribute() {
 	inc.mu.Lock()
 	defer inc.mu.Unlock()
+
+	bankBalance, err := inc.balances.Balance(inc.bankOwner)
+	if err != nil {
+		inc.log.Error("can't fetch balance of banking account",
+			zap.String("error", err.Error()))
+
+		return
+	}
+
+	_ = bankBalance
 }
diff --git a/pkg/innerring/settlement.go b/pkg/innerring/settlement.go
index 598fadeeb..080c5c4f4 100644
--- a/pkg/innerring/settlement.go
+++ b/pkg/innerring/settlement.go
@@ -259,6 +259,10 @@ func (b basicIncomeSettlementDeps) Estimations(epoch uint64) ([]*wrapper.Estimat
 	return result, nil
 }
 
+func (b basicIncomeSettlementDeps) Balance(id *owner.ID) (*big.Int, error) {
+	return b.balanceClient.BalanceOf(id)
+}
+
 func (s *auditSettlementCalculator) ProcessAuditSettlements(epoch uint64) {
 	(*audit.Calculator)(s).Calculate(&audit.CalculatePrm{
 		Epoch: epoch,
@@ -271,6 +275,7 @@ func (b *basicSettlementConstructor) CreateContext(epoch uint64) (*basic.IncomeS
 		Epoch:       epoch,
 		Rate:        b.dep,
 		Estimations: b.dep,
+		Balances:    b.dep,
 		Container:   b.dep,
 		Placement:   b.dep,
 		Exchange:    b.dep,