From 167124bfa3c621bb420fd683f2fe27514a16ee29 Mon Sep 17 00:00:00 2001
From: "duck." <me@duck.me.uk>
Date: Thu, 3 Apr 2025 08:13:42 +0100
Subject: [PATCH] tariff/octopus: Support non-Direct Debit tariffs (#20306)

---
 tariff/octopus.go                             | 43 +++++++++++++------
 tariff/octopus/rest/api.go                    |  8 ++++
 tariff/octopus_test.go                        |  6 ++-
 .../tariff/octopus-productcode.yaml           |  7 +++
 4 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/tariff/octopus.go b/tariff/octopus.go
index a1d053c17..12acda590 100644
--- a/tariff/octopus.go
+++ b/tariff/octopus.go
@@ -16,11 +16,12 @@ import (
 )
 
 type Octopus struct {
-	log         *util.Logger
-	region      string
-	productCode string
-	apikey      string
-	data        *util.Monitor[api.Rates]
+	log           *util.Logger
+	region        string
+	productCode   string
+	apikey        string
+	paymentMethod string
+	data          *util.Monitor[api.Rates]
 }
 
 var _ api.Tariff = (*Octopus)(nil)
@@ -34,6 +35,7 @@ func NewOctopusFromConfig(other map[string]interface{}) (api.Tariff, error) {
 		Region      string
 		Tariff      string // DEPRECATED: use ProductCode
 		ProductCode string
+		DirectDebit bool
 		ApiKey      string
 	}
 
@@ -65,13 +67,18 @@ func NewOctopusFromConfig(other map[string]interface{}) (api.Tariff, error) {
 			return nil, errors.New("invalid apikey format")
 		}
 	}
-
+	paymentMethod := octoRest.RatePaymentMethodDirectDebit
+	if !cc.DirectDebit {
+		// Not using Direct Debit, filter by non-Direct Debit tariff entries
+		paymentMethod = octoRest.RatePaymentMethodNotDirectDebit
+	}
 	t := &Octopus{
-		log:         logger,
-		region:      cc.Region,
-		productCode: cc.ProductCode,
-		apikey:      cc.ApiKey,
-		data:        util.NewMonitor[api.Rates](2 * time.Hour),
+		log:           logger,
+		region:        cc.Region,
+		productCode:   cc.ProductCode,
+		apikey:        cc.ApiKey,
+		paymentMethod: paymentMethod,
+		data:          util.NewMonitor[api.Rates](2 * time.Hour),
 	}
 
 	done := make(chan error)
@@ -122,9 +129,21 @@ func (t *Octopus) run(done chan error) {
 
 		data := make(api.Rates, 0, len(res.Results))
 		for _, r := range res.Results {
+			if t.paymentMethod != "" && r.PaymentMethod != t.paymentMethod {
+				// A Payment Method filter is set, and this Tariff entry does not match our filter.
+				continue
+			}
+			// ValidityEnd can be zero (wonderful) which just means that the tariff has no present expected end.
+			// We need to catch that and set the date to something way in the future.
+			rateEnd := r.ValidityEnd
+			if rateEnd.IsZero() {
+				t.log.DEBUG.Printf("handling rate with indefinite length: %v", r.ValidityStart)
+				// Currently adds a year from the start date
+				rateEnd = r.ValidityStart.AddDate(1, 0, 0)
+			}
 			ar := api.Rate{
 				Start: r.ValidityStart,
-				End:   r.ValidityEnd,
+				End:   rateEnd,
 				// UnitRates are supplied inclusive of tax, though this could be flipped easily with a config flag.
 				Price: r.PriceInclusiveTax / 1e2,
 			}
diff --git a/tariff/octopus/rest/api.go b/tariff/octopus/rest/api.go
index a1308edd3..67a38a95f 100644
--- a/tariff/octopus/rest/api.go
+++ b/tariff/octopus/rest/api.go
@@ -40,9 +40,17 @@ type UnitRates struct {
 	Results  []Rate `json:"results"`
 }
 
+// RatePaymentMethodDirectDebit is set when the rate only applies when the customer is paying with Direct Debit.
+const RatePaymentMethodDirectDebit = "DIRECT_DEBIT"
+
+// RatePaymentMethodNotDirectDebit is set when the rate only applies when the customer is paying with
+// any payment means that ISN'T Direct Debit (say, pre-payment meters)
+const RatePaymentMethodNotDirectDebit = "NON_DIRECT_DEBIT"
+
 type Rate struct {
 	ValidityStart     time.Time `json:"valid_from"`
 	ValidityEnd       time.Time `json:"valid_to"`
 	PriceInclusiveTax float64   `json:"value_inc_vat"`
 	PriceExclusiveTax float64   `json:"value_exc_vat"`
+	PaymentMethod     string    `json:"payment_method"`
 }
diff --git a/tariff/octopus_test.go b/tariff/octopus_test.go
index a65c41cb4..19bbd26a5 100644
--- a/tariff/octopus_test.go
+++ b/tariff/octopus_test.go
@@ -12,8 +12,9 @@ func TestOctopusConfigParse(t *testing.T) {
 
 	// This test will start failing if you remove the deprecated "tariff" config var.
 	validTariffConfig := map[string]interface{}{
-		"region": "H",
-		"tariff": "GO-22-03-29",
+		"region":      "H",
+		"tariff":      "GO-22-03-29",
+		"directDebit": "True",
 	}
 
 	_, err := NewOctopusFromConfig(validTariffConfig)
@@ -22,6 +23,7 @@ func TestOctopusConfigParse(t *testing.T) {
 	validProductCodeConfig := map[string]interface{}{
 		"region":      "H",
 		"productcode": "GO-22-03-29",
+		"directDebit": "False",
 	}
 
 	_, err = NewOctopusFromConfig(validProductCodeConfig)
diff --git a/templates/definition/tariff/octopus-productcode.yaml b/templates/definition/tariff/octopus-productcode.yaml
index 1d5e0b041..b7ff2e98b 100644
--- a/templates/definition/tariff/octopus-productcode.yaml
+++ b/templates/definition/tariff/octopus-productcode.yaml
@@ -20,7 +20,14 @@ params:
     help:
       de: "Die DNO-Region, in der Sie sich befinden. Weitere Informationen: https://www.energy-stats.uk/dno-region-codes-explained/"
       en: "The DNO region you are located in. More information: https://www.energy-stats.uk/dno-region-codes-explained/"
+  - name: directDebit
+    type: bool
+    default: true
+    help:
+      de: "Ich benutze den BACS-Lastschrifttarif."
+      en: "Use Direct Debit tariff rates."
 render: |
   type: octopusenergy
   productCode: {{ .productCode }}
   region: {{ .region }}
+  directDebit: {{ .directDebit }}