From 667978db3e8670bf0820e495eabce5a39a63cc48 Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Tue, 28 Oct 2025 08:18:32 +0100
Subject: [PATCH] Mqtt: marshal solar forecast as JSON (#24810)

---
 api/rates.go         | 2 +-
 core/site_tariffs.go | 2 +-
 core/solar.go        | 9 +++++++++
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/api/rates.go b/api/rates.go
index e1682da51..66695ef83 100644
--- a/api/rates.go
+++ b/api/rates.go
@@ -47,7 +47,7 @@ func (rr Rates) At(ts time.Time) (Rate, error) {
 	return Rate{}, ErrNotAvailable
 }
 
-var _ BytesMarshaler = Rates{}
+var _ BytesMarshaler = (*Rates)(nil)
 
 // MarshalBytes implements server.BytesMarshaler
 func (r Rates) MarshalBytes() ([]byte, error) {
diff --git a/core/site_tariffs.go b/core/site_tariffs.go
index fb92a8667..0bd2d247b 100644
--- a/core/site_tariffs.go
+++ b/core/site_tariffs.go
@@ -20,7 +20,7 @@ type solarDetails struct {
 	Today            dailyDetails `json:"today,omitempty"`            // tomorrow
 	Tomorrow         dailyDetails `json:"tomorrow,omitempty"`         // tomorrow
 	DayAfterTomorrow dailyDetails `json:"dayAfterTomorrow,omitempty"` // day after tomorrow
-	Timeseries       []tsEntry    `json:"timeseries,omitempty"`       // timeseries of forecasted energy
+	Timeseries       timeseries   `json:"timeseries,omitempty"`       // timeseries of forecasted energy
 }
 
 type dailyDetails struct {
diff --git a/core/solar.go b/core/solar.go
index 38f959c60..b409c4111 100644
--- a/core/solar.go
+++ b/core/solar.go
@@ -1,6 +1,7 @@
 package core
 
 import (
+	"encoding/json"
 	"slices"
 	"time"
 
@@ -8,6 +9,14 @@ import (
 	"github.com/samber/lo"
 )
 
+type timeseries []tsEntry
+
+var _ api.BytesMarshaler = (*timeseries)(nil)
+
+func (ts timeseries) MarshalBytes() ([]byte, error) {
+	return json.Marshal(ts)
+}
+
 type tsEntry struct {
 	Timestamp time.Time `json:"ts"`
 	Value     float64   `json:"val"`