add processor to scale int values

internal/processor/int-scale.go

@@ -0,0 +1,70 @@
+package processor
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/jwetzell/showbridge-go/internal/config"
+)
+
+type IntScale struct {
+	OutMin int
+	OutMax int
+	InMin  int
+	InMax  int
+	config config.ProcessorConfig
+}
+
+func (ir *IntScale) Process(ctx context.Context, payload any) (any, error) {
+	payloadInt, ok := GetAnyAs[int](payload)
+	if !ok {
+		return nil, errors.New("int.scale can only process an int")
+	}
+
+	payloadInt = (payloadInt-ir.InMin)*(ir.OutMax-ir.OutMin)/(ir.InMax-ir.InMin) + ir.OutMin
+	return payloadInt, nil
+}
+
+func (ir *IntScale) Type() string {
+	return ir.config.Type
+}
+
+func init() {
+	RegisterProcessor(ProcessorRegistration{
+		Type: "int.scale",
+		New: func(config config.ProcessorConfig) (Processor, error) {
+			params := config.Params
+
+			inMinInt, err := params.GetInt("inMin")
+			if err != nil {
+				return nil, fmt.Errorf("int.scale inMin error: %w", err)
+			}
+
+			inMaxInt, err := params.GetInt("inMax")
+			if err != nil {
+				return nil, fmt.Errorf("int.scale inMax error: %w", err)
+			}
+
+			if inMaxInt < inMinInt {
+				return nil, errors.New("int.scale inMax must be greater than inMin")
+			}
+
+			outMinInt, err := params.GetInt("outMin")
+			if err != nil {
+				return nil, fmt.Errorf("int.scale outMin error: %w", err)
+			}
+
+			outMaxInt, err := params.GetInt("outMax")
+			if err != nil {
+				return nil, fmt.Errorf("int.scale outMax error: %w", err)
+			}
+
+			if outMaxInt < outMinInt {
+				return nil, errors.New("int.scale outMax must be greater than outMin")
+			}
+
+			return &IntScale{config: config, InMin: inMinInt, InMax: inMaxInt, OutMin: outMinInt, OutMax: outMaxInt}, nil
+		},
+	})
+}

internal/processor/test/int-scale_test.go

@@ -0,0 +1,170 @@
+package processor_test
+
+import (
+	"testing"
+
+	"github.com/jwetzell/showbridge-go/internal/config"
+	"github.com/jwetzell/showbridge-go/internal/processor"
+)
+
+func TestIntScaleFromRegistry(t *testing.T) {
+	registration, ok := processor.ProcessorRegistry["int.scale"]
+	if !ok {
+		t.Fatalf("int.scale processor not registered")
+	}
+
+	processorInstance, err := registration.New(config.ProcessorConfig{
+		Type: "int.scale",
+		Params: map[string]any{
+			"inMin":  0,
+			"inMax":  10,
+			"outMin": 0,
+			"outMax": 127,
+		},
+	})
+
+	if err != nil {
+		t.Fatalf("failed to create int.scale processor: %s", err)
+	}
+
+	if processorInstance.Type() != "int.scale" {
+		t.Fatalf("int.scale processor has wrong type: %s", processorInstance.Type())
+	}
+}
+
+func TestGoodIntScale(t *testing.T) {
+	tests := []struct {
+		name     string
+		payload  any
+		params   map[string]any
+		expected int
+	}{
+		{
+			name: "0-10 -> 0-127",
+			params: map[string]any{
+				"inMin":  0,
+				"inMax":  10,
+				"outMin": 0,
+				"outMax": 127,
+			},
+			payload:  5,
+			expected: 63,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			registration, ok := processor.ProcessorRegistry["int.scale"]
+			if !ok {
+				t.Fatalf("int.scale processor not registered")
+			}
+
+			processorInstance, err := registration.New(config.ProcessorConfig{
+				Type:   "int.scale",
+				Params: test.params,
+			})
+
+			if err != nil {
+				t.Fatalf("int.scale failed to create processor: %s", err)
+			}
+
+			got, err := processorInstance.Process(t.Context(), test.payload)
+			if err != nil {
+				t.Fatalf("int.scale processing failed: %s", err)
+			}
+
+			gotInt, ok := got.(int)
+			if !ok {
+				t.Fatalf("int.scale returned a %T payload: %s", got, got)
+			}
+
+			if gotInt != test.expected {
+				t.Fatalf("int.scale got %d, expected %d", gotInt, test.expected)
+			}
+		})
+	}
+}
+
+func TestBadIntScale(t *testing.T) {
+	tests := []struct {
+		name        string
+		params      map[string]any
+		payload     any
+		errorString string
+	}{
+		{
+			name:        "no inMin param",
+			payload:     "hello",
+			params:      map[string]any{"inMax": 10, "outMin": 0, "outMax": 127},
+			errorString: "int.scale inMin error: not found",
+		},
+		{
+			name:        "no inMax param",
+			payload:     "hello",
+			params:      map[string]any{"inMin": 0, "outMin": 0, "outMax": 127},
+			errorString: "int.scale inMax error: not found",
+		},
+		{
+			name:        "no outMin param",
+			payload:     "hello",
+			params:      map[string]any{"inMin": 0, "inMax": 10, "outMax": 127},
+			errorString: "int.scale outMin error: not found",
+		},
+		{
+			name:        "no outMax param",
+			payload:     "hello",
+			params:      map[string]any{"inMin": 0, "inMax": 10, "outMin": 0},
+			errorString: "int.scale outMax error: not found",
+		},
+		{
+			name:        "inMin param not a number",
+			payload:     "hello",
+			params:      map[string]any{"inMin": "0", "max": 10, "outMin": 0, "outMax": 127},
+			errorString: "int.scale inMin error: not a number",
+		},
+		{
+			name:        "inMax param not a number",
+			payload:     "hello",
+			params:      map[string]any{"inMin": 0, "inMax": "10", "outMin": 0, "outMax": 127},
+			errorString: "int.scale inMax error: not a number",
+		},
+		{
+			name:        "inMax less than inMin",
+			payload:     "hello",
+			params:      map[string]any{"inMin": 10, "inMax": 0, "outMin": 0, "outMax": 127},
+			errorString: "int.scale inMax must be greater than inMin",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+
+			registration, ok := processor.ProcessorRegistry["int.scale"]
+			if !ok {
+				t.Fatalf("int.scale processor not registered")
+			}
+
+			processorInstance, err := registration.New(config.ProcessorConfig{
+				Type:   "int.scale",
+				Params: test.params,
+			})
+
+			if err != nil {
+				if test.errorString != err.Error() {
+					t.Fatalf("int.scale got error '%s', expected '%s'", err.Error(), test.errorString)
+				}
+				return
+			}
+
+			got, err := processorInstance.Process(t.Context(), test.payload)
+
+			if err == nil {
+				t.Fatalf("int.scale expected to fail but got payload: %s", got)
+			}
+
+			if err.Error() != test.errorString {
+				t.Fatalf("int.scale got error '%s', expected '%s'", err.Error(), test.errorString)
+			}
+		})
+	}
+}

schema/processors.schema.json

@@ -290,6 +290,41 @@
         "required": ["type", "params"],
         "additionalProperties": false
       },
+      {
+        "type": "object",
+        "title": "Scale Int",
+        "properties": {
+          "type": {
+            "type": "string",
+            "const": "int.scale"
+          },
+          "params": {
+            "type": "object",
+            "properties": {
+              "inMin": {
+                "title": "Input Minimum",
+                "type": "integer"
+              },
+              "inMax": {
+                "title": "Input Maximum",
+                "type": "integer"
+              },
+              "outMin": {
+                "title": "Output Minimum",
+                "type": "integer"
+              },
+              "outMax": {
+                "title": "Output Maximum",
+                "type": "integer"
+              }
+            },
+            "required": ["inMin", "inMax", "outMin", "outMax"],
+            "additionalProperties": false
+          }
+        },
+        "required": ["type", "params"],
+        "additionalProperties": false
+      },
       {
         "type": "object",
         "title": "Decode JSON",