chore: refactor plugin structure (#18335)

plugin/javascript/registry.go

@@ -0,0 +1,87 @@
+package javascript
+
+import (
+	"fmt"
+	"log"
+	"strings"
+	"sync"
+
+	"github.com/evcc-io/evcc/util"
+	"github.com/robertkrimen/otto"
+	_ "github.com/robertkrimen/otto/underscore"
+	"github.com/samber/lo"
+)
+
+var (
+	mu       sync.Mutex
+	registry = make(map[string]*otto.Otto)
+)
+
+// expose mutex to serialize VM access
+func Lock() {
+	mu.Lock()
+}
+
+// expose mutex to serialize VM access
+func Unlock() {
+	mu.Unlock()
+}
+
+// RegisteredVM returns a JS VM. If name is not empty, it will return a shared instance.
+func RegisteredVM(name, init string) (*otto.Otto, error) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	name = strings.ToLower(name)
+	vm, ok := registry[name]
+
+	// create new VM
+	if !ok {
+		vm = otto.New()
+		if err := setConsole(vm, name); err != nil {
+			return nil, err
+		}
+
+		if init != "" {
+			if _, err := vm.Run(init); err != nil {
+				return nil, err
+			}
+		}
+
+		if name != "" {
+			registry[name] = vm
+		}
+	}
+
+	return vm, nil
+}
+
+func setConsole(vm *otto.Otto, suffix string) error {
+	name := "js"
+	if suffix != "" {
+		name = name + "-" + suffix
+	}
+
+	log := util.NewLogger(name)
+
+	console := map[string]any{
+		"trace": printer(log.TRACE),
+		"log":   printer(log.DEBUG),
+		"info":  printer(log.INFO),
+		"error": printer(log.ERROR),
+	}
+
+	return vm.Set("console", console)
+}
+
+func printer(log *log.Logger) func(call otto.FunctionCall) otto.Value {
+	return func(call otto.FunctionCall) otto.Value {
+		output := lo.Map(call.ArgumentList, func(a otto.Value, _ int) string {
+			return fmt.Sprintf("%v", a)
+		})
+
+		log.Println(strings.Join(output, " "))
+
+		return otto.UndefinedValue()
+	}
+}