Revert commits

This reverts commit 993b6a7.

Revert "add comments"

This reverts commit 69ad29b.

Revert "fix debug message"

This reverts commit f92a088.

Revert "add TODO comment on strange condition"

This reverts commit 44cd09f.

Revert "remove dead code"

This reverts commit 31d7d78.

charger/ocpp/connector.go

@@ -29,8 +29,9 @@ type Connector struct {
 	meterUpdated time.Time
 	measurements map[types.Measurand]types.SampledValue
 
-	txnId int
-	idTag string
+	txnCount int // change initial value to the last known global transaction. Needs persistence
+	txnId    int
+	idTag    string
 
 	remoteIdTag string
 }

charger/ocpp/connector_core.go

@@ -64,7 +64,7 @@ func (conn *Connector) MeterValues(request *core.MeterValuesRequest) (*core.Mete
 		(conn.status.Status == core.ChargePointStatusCharging ||
 			conn.status.Status == core.ChargePointStatusSuspendedEV ||
 			conn.status.Status == core.ChargePointStatusSuspendedEVSE) {
-		conn.log.DEBUG.Printf("recovered existing transaction: %d", *request.TransactionId)
+		conn.log.DEBUG.Printf("hijacking transaction: %d", *request.TransactionId)
 		conn.txnId = *request.TransactionId
 	}
 
@@ -92,7 +92,6 @@ func (conn *Connector) StartTransaction(request *core.StartTransactionRequest) (
 	defer conn.mu.Unlock()
 
 	// expired request
-	// TODO: check if this is the correct way to handle expired requests. AuthorirzationStatusExpired is related to the idTag, not the request itself
 	if request.Timestamp != nil && conn.clock.Since(request.Timestamp.Time) > Timeout {
 		res := &core.StartTransactionConfirmation{
 			IdTagInfo: &types.IdTagInfo{
@@ -103,7 +102,8 @@ func (conn *Connector) StartTransaction(request *core.StartTransactionRequest) (
 		return res, nil
 	}
 
-	conn.txnId = instance.NewTransactionID()
+	conn.txnCount++
+	conn.txnId = conn.txnCount
 	conn.idTag = request.IdTag
 
 	res := &core.StartTransactionConfirmation{
@@ -140,6 +140,17 @@ func (conn *Connector) StopTransaction(request *core.StopTransactionRequest) (*c
 	conn.mu.Lock()
 	defer conn.mu.Unlock()
 
+	// expired request
+	if request.Timestamp != nil && conn.clock.Since(request.Timestamp.Time) > Timeout {
+		res := &core.StopTransactionConfirmation{
+			IdTagInfo: &types.IdTagInfo{
+				Status: types.AuthorizationStatusExpired, // reject
+			},
+		}
+
+		return res, nil
+	}
+
 	conn.txnId = 0
 	conn.idTag = ""
 

charger/ocpp/cs.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"sync"
-	"time"
 
 	"github.com/evcc-io/evcc/util"
 	ocpp16 "github.com/lorenzodonini/ocpp-go/ocpp1.6"
@@ -14,8 +13,7 @@ type CS struct {
 	mu  sync.Mutex
 	log *util.Logger
 	ocpp16.CentralSystem
-	cps   map[string]*CP
-	txnId int
+	cps map[string]*CP
 }
 
 // Register registers a charge point with the central system.
@@ -108,17 +106,3 @@ func (cs *CS) ChargePointDisconnected(chargePoint ocpp16.ChargePointConnection)
 		cp.connect(false)
 	}
 }
-
-// NewTransactionID returns a globally unique transaction id
-func (cs *CS) NewTransactionID() int {
-	cs.mu.Lock()
-	defer cs.mu.Unlock()
-
-	// initialize new transactionId epoch
-	if cs.txnId == 0 {
-		cs.txnId = int(time.Now().UTC().Unix())
-	}
-
-	cs.txnId++
-	return cs.txnId
-}