From 78b7bfd6c36ac20145f90d537eb1f2e41e16b1be Mon Sep 17 00:00:00 2001
From: andig <andi@evcc.io>
Date: Sat, 14 Sep 2024 21:00:00 +0200
Subject: [PATCH] SolarMax: add battery discharge control (#16110)

---
 provider/error.go                             | 45 ++++++++++++
 provider/random.go                            | 46 ++++++++++++
 .../definition/meter/solarmax-maxstorage.yaml | 72 +++++++++++++++++++
 3 files changed, 163 insertions(+)
 create mode 100644 provider/error.go
 create mode 100644 provider/random.go

diff --git a/provider/error.go b/provider/error.go
new file mode 100644
index 0000000000..96087ccb9d
--- /dev/null
+++ b/provider/error.go
@@ -0,0 +1,45 @@
+package provider
+
+import (
+	"fmt"
+
+	"github.com/evcc-io/evcc/util"
+)
+
+type errorProvider struct {
+	err error
+}
+
+func init() {
+	registry.Add("error", NewErrorFromConfig)
+}
+
+// NewErrorFromConfig creates error provider
+func NewErrorFromConfig(other map[string]interface{}) (Provider, error) {
+	var cc struct {
+		Error string
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	err := knownErrors([]byte(cc.Error))
+	if err == nil {
+		return nil, fmt.Errorf("unknown error: %s", cc.Error)
+	}
+
+	o := &errorProvider{
+		err: err,
+	}
+
+	return o, nil
+}
+
+var _ SetIntProvider = (*errorProvider)(nil)
+
+func (o *errorProvider) IntSetter(param string) (func(int64) error, error) {
+	return func(int64) error {
+		return o.err
+	}, nil
+}
diff --git a/provider/random.go b/provider/random.go
new file mode 100644
index 0000000000..e749b582b9
--- /dev/null
+++ b/provider/random.go
@@ -0,0 +1,46 @@
+package provider
+
+import (
+	"math"
+	"math/rand/v2"
+
+	"github.com/evcc-io/evcc/util"
+)
+
+type randomProvider struct {
+	set Config
+}
+
+func init() {
+	registry.Add("random", NewRandomFromConfig)
+}
+
+// NewRandomFromConfig creates random provider
+func NewRandomFromConfig(other map[string]interface{}) (Provider, error) {
+	var cc struct {
+		Set Config
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	o := &randomProvider{
+		set: cc.Set,
+	}
+
+	return o, nil
+}
+
+var _ SetIntProvider = (*randomProvider)(nil)
+
+func (o *randomProvider) IntSetter(param string) (func(int64) error, error) {
+	set, err := NewIntSetterFromConfig(param, o.set)
+	if err != nil {
+		return nil, err
+	}
+
+	return func(int64) error {
+		return set(rand.Int64N(math.MaxInt64-1) + 1)
+	}, nil
+}
diff --git a/templates/definition/meter/solarmax-maxstorage.yaml b/templates/definition/meter/solarmax-maxstorage.yaml
index eaf689517d..dccbbf679d 100644
--- a/templates/definition/meter/solarmax-maxstorage.yaml
+++ b/templates/definition/meter/solarmax-maxstorage.yaml
@@ -47,5 +47,77 @@ render: |
       address: 122 # Batterie Soc
       type: input
       decode: int16
+  batterymode:
+    source: watchdog
+    timeout: {{ .watchdog }}
+    reset: 1 # reset watchdog on normal
+    set:
+      source: switch
+      switch:
+      - case: 1 # normal
+        set:
+          source: sequence
+          set:
+          - source: const
+            value: 7000
+            set:
+              source: modbus
+              {{- include "modbus" . | indent 12 }}
+              register:
+                address: 140
+                type: writemultiple
+                decode: int16
+          - source: const
+            value: 7000
+            set:
+              source: modbus
+              {{- include "modbus" . | indent 12 }}
+              register:
+                address: 141
+                type: writemultiple
+                decode: int16
+          - source: const
+            value: 0
+            set:
+              source: modbus
+              {{- include "modbus" . | indent 12 }}
+              register:
+                address: 142
+                type: writemultiple
+                decode: int16
+      - case: 2 # hold
+        set:
+          source: sequence
+          set:
+          - source: const
+            value: 0
+            set:
+              source: modbus
+              {{- include "modbus" . | indent 12 }}
+              register:
+                address: 140
+                type: writemultiple
+                decode: int16
+          - source: const
+            value: 0
+            set:
+              source: modbus
+              {{- include "modbus" . | indent 12 }}
+              register:
+                address: 141
+                type: writemultiple
+                decode: int16
+          - source: random
+            set:
+              source: modbus
+              {{- include "modbus" . | indent 12 }}
+              register:
+                address: 142
+                type: writemultiple
+                decode: int16
+      - case: 3 # charge (not implemented)
+        set:
+          source: error
+          error: ErrNotImplemented
   capacity: {{ .capacity }} # kWh
   {{- end }}