From ec1d76e51e10d527d9a7ce7c3a47ddd4ef71743a Mon Sep 17 00:00:00 2001
From: Matheus Sampaio Queiroga <srherobrine20@gmail.com>
Date: Mon, 28 Apr 2025 16:10:53 -0300
Subject: [PATCH] Start class implementation

---
 class.go                        | 79 +++++++++++++++++++++++++++++++++
 internal/examples/class/main.go | 29 ++++++++++++
 internal/napi/class.go          | 27 +++++++++++
 3 files changed, 135 insertions(+)
 create mode 100644 class.go
 create mode 100644 internal/examples/class/main.go
 create mode 100644 internal/napi/class.go

diff --git a/class.go b/class.go
new file mode 100644
index 0000000..66f8bf2
--- /dev/null
+++ b/class.go
@@ -0,0 +1,79 @@
+package napi
+
+import (
+	"fmt"
+	"reflect"
+	"unsafe"
+
+	"sirherobrine23.com.br/Sirherobrine23/napi-go/internal/napi"
+)
+
+type (
+	PropertyDescriptor = napi.PropertyDescriptor
+	
+	ClassType interface {
+		Contructor(env EnvType, this ValueType, args []ValueType) (*Object, error)
+	}
+
+	Class[T ClassType] struct {
+		value
+		Class        T
+		classReflect reflect.Type
+	}
+)
+
+const (
+	PropertyAttributesDefault           = napi.Default
+	PropertyAttributesWritable          = napi.Writable
+	PropertyAttributesEnumerable        = napi.Enumerable
+	PropertyAttributesConfigurable      = napi.Configurable
+	PropertyAttributesStatic            = napi.Static
+	PropertyAttributesDefaultMethod     = napi.DefaultMethod
+	PropertyAttributesDefaultJSProperty = napi.DefaultJSProperty
+)
+
+func CreateClass[T ClassType](env EnvType, propertys []PropertyDescriptor) (*Class[T], error) {
+	ptrType := reflect.TypeFor[T]()
+	switch ptrType.Kind() {
+	case reflect.Struct:
+	case reflect.Pointer:
+		if ptrType = ptrType.Elem(); ptrType.Kind() != reflect.Struct {
+			return nil, fmt.Errorf("type %s is not a struct", ptrType.Name())
+		}
+	default:
+		return nil, fmt.Errorf("type %s is not a struct", ptrType.Name())
+	}
+
+	startStruct := &Class[T]{classReflect: ptrType}
+	value, status := napi.DefineClass(env.NapiValue(), ptrType.Name(),
+		func(env napi.Env, info napi.CallbackInfo) napi.Value {
+			startStruct.Class = reflect.New(ptrType).Interface().(T)
+			cbInfo, status := napi.GetCbInfo(env, info)
+			if err := status.ToError(); err != nil {
+				ThrowError(N_APIEnv(env), "", err.Error())
+				return nil
+			}
+
+			gonapiEnv := N_APIEnv(env)
+			this := N_APIValue(gonapiEnv, cbInfo.This)
+			args := make([]ValueType, len(cbInfo.Args))
+			for i, cbArg := range cbInfo.Args {
+				args[i] = N_APIValue(gonapiEnv, cbArg)
+			}
+
+			res, err := startStruct.Class.Contructor(gonapiEnv, this, args)
+			if err != nil {
+				ThrowError(gonapiEnv, "", err.Error())
+			} else if res == nil {
+				und, _ := gonapiEnv.Undefined()
+				return und.NapiValue()
+			}
+			napi.Wrap(env, res.NapiValue(), unsafe.Pointer(startStruct), nil, nil)
+			return res.NapiValue()
+		}, propertys)
+	if err := status.ToError(); err != nil {
+		return nil, err
+	}
+	startStruct.value = N_APIValue(env, value)
+	return startStruct, nil
+}
diff --git a/internal/examples/class/main.go b/internal/examples/class/main.go
new file mode 100644
index 0000000..46f1acf
--- /dev/null
+++ b/internal/examples/class/main.go
@@ -0,0 +1,29 @@
+package main
+
+import (
+	_ "unsafe"
+
+	_ "sirherobrine23.com.br/Sirherobrine23/napi-go/entry"
+
+	"sirherobrine23.com.br/Sirherobrine23/napi-go"
+)
+
+func main() {}
+
+//go:linkname Register sirherobrine23.com.br/Sirherobrine23/napi-go/entry.Register
+func Register(env napi.EnvType, export *napi.Object) {
+	class, err := napi.CreateClass[*ClassTest](env, []napi.PropertyDescriptor{})
+	if err != nil {
+		panic(err)
+	}
+	
+	export.Set("class", class)
+}
+
+type ClassTest struct{}
+
+func (class *ClassTest) Contructor(env napi.EnvType, this napi.ValueType, args []napi.ValueType) (*napi.Object, error) {
+	obj, _ := napi.CreateObject(env)
+
+	return obj, nil
+}
diff --git a/internal/napi/class.go b/internal/napi/class.go
new file mode 100644
index 0000000..4879edd
--- /dev/null
+++ b/internal/napi/class.go
@@ -0,0 +1,27 @@
+package napi
+
+// #include <node/node_api.h>
+import "C"
+
+import "unsafe"
+
+func DefineClass(env Env, name string, constructor Callback, Property []PropertyDescriptor) (Value, Status) {
+	var pro *C.napi_property_descriptor
+	if len(Property) > 0 {
+		pro = (*C.napi_property_descriptor)(unsafe.Pointer(&Property[0]))
+	}
+
+	var result Value
+	call := &constructor
+	status := Status(C.napi_define_class(
+		C.napi_env(env),
+		C.CString(name),
+		C.size_t(len(name)),
+		C.napi_callback(unsafe.Pointer(call)),
+		nil,
+		C.size_t(len(Property)),
+		pro,
+		(*C.napi_value)(unsafe.Pointer(&result)),
+	))
+	return result, status
+}
-- 
2.49.0