chore: Support nested attributes in conversion logic for generating Resource Model from API response

internal/common/autogeneration/marshal.go

@@ -1,6 +1,7 @@
 package autogeneration
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"reflect"
@@ -38,7 +39,10 @@ func Marshal(model any, isUpdate bool) ([]byte, error) {
 }
 
 // Unmarshal gets a JSON (e.g. from an Atlas response) and unmarshals it into a Terraform model.
-// It supports the following Terraform model types: String, Bool, Int64, Float64.
+// It supports the following Terraform model types: String, Bool, Int64, Float64, Object, List, Set.
+// Map is not supported yet as it is not used in the Atlas API.
+// Attributes that are in JSON but not in the model are ignored, no error is returned.
+// Object attributes that are unknown are converted to null as all values must be known in the response state.
 func Unmarshal(raw []byte, model any) error {
 	var objJSON map[string]any
 	if err := json.Unmarshal(raw, &objJSON); err != nil {
@@ -73,7 +77,7 @@ func marshalAttr(attrNameModel string, attrValModel reflect.Value, objJSON map[s
 	if !ok {
 		panic("marshal expects only Terraform types in the model")
 	}
-	val, err := getAttr(obj)
+	val, err := getModelAttr(obj)
 	if err != nil {
 		return err
 	}
@@ -83,13 +87,15 @@ func marshalAttr(attrNameModel string, attrValModel reflect.Value, objJSON map[s
 	return nil
 }
 
-func getAttr(val attr.Value) (any, error) {
+func getModelAttr(val attr.Value) (any, error) {
 	if val.IsNull() || val.IsUnknown() {
 		return nil, nil // skip null or unknown values
 	}
 	switch v := val.(type) {
 	case types.String:
 		return v.ValueString(), nil
+	case types.Bool:
+		return v.ValueBool(), nil
 	case types.Int64:
 		return v.ValueInt64(), nil
 	case types.Float64:
@@ -110,7 +116,7 @@ func getAttr(val attr.Value) (any, error) {
 func getListAttr(elms []attr.Value) (any, error) {
 	arr := make([]any, 0)
 	for _, attr := range elms {
-		valChild, err := getAttr(attr)
+		valChild, err := getModelAttr(attr)
 		if err != nil {
 			return nil, err
 		}
@@ -121,10 +127,12 @@ func getListAttr(elms []attr.Value) (any, error) {
 	return arr, nil
 }
 
+// getMapAttr gets a map of attributes and returns a map of JSON attributes.
+// keepKeyCase is used for types.Map to keep key case. However, we want to use JSON key case for types.Object
 func getMapAttr(elms map[string]attr.Value, keepKeyCase bool) (any, error) {
-	obj := make(map[string]any)
+	objJSON := make(map[string]any)
 	for name, attr := range elms {
-		valChild, err := getAttr(attr)
+		valChild, err := getModelAttr(attr)
 		if err != nil {
 			return nil, err
 		}
@@ -133,10 +141,10 @@ func getMapAttr(elms map[string]attr.Value, keepKeyCase bool) (any, error) {
 			if keepKeyCase {
 				nameJSON = name
 			}
-			obj[nameJSON] = valChild
+			objJSON[nameJSON] = valChild
 		}
 	}
-	return obj, nil
+	return objJSON, nil
 }
 
 func unmarshalAttrs(objJSON map[string]any, model any) error {
@@ -153,6 +161,7 @@ func unmarshalAttrs(objJSON map[string]any, model any) error {
 			return err
 		}
 	}
+	convertUnknownToNull(valModel)
 	return nil
 }
 
@@ -164,26 +173,211 @@ func unmarshalAttr(attrNameJSON string, attrObjJSON any, valModel reflect.Value)
 	}
 	switch v := attrObjJSON.(type) {
 	case string:
-		return setAttrModel(attrNameModel, fieldModel, types.StringValue(v))
+		return setAttrTfModel(attrNameModel, fieldModel, types.StringValue(v))
 	case bool:
-		return setAttrModel(attrNameModel, fieldModel, types.BoolValue(v))
+		return setAttrTfModel(attrNameModel, fieldModel, types.BoolValue(v))
 	case float64: // number: try int or float
-		if setAttrModel(attrNameModel, fieldModel, types.Float64Value(v)) == nil {
+		if setAttrTfModel(attrNameModel, fieldModel, types.Float64Value(v)) == nil {
 			return nil
 		}
-		return setAttrModel(attrNameModel, fieldModel, types.Int64Value(int64(v)))
+		return setAttrTfModel(attrNameModel, fieldModel, types.Int64Value(int64(v)))
 	case nil:
 		return nil // skip nil values, no need to set anything
+	case map[string]any:
+		obj, ok := fieldModel.Interface().(types.Object)
+		if !ok {
+			return fmt.Errorf("unmarshal expects object for field %s", attrNameJSON)
+		}
+		objNew, err := setObjAttrModel(obj, v)
+		if err != nil {
+			return err
+		}
+		return setAttrTfModel(attrNameModel, fieldModel, objNew)
+	case []any:
+		switch collection := fieldModel.Interface().(type) {
+		case types.List:
+			list, err := setListAttrModel(collection, v)
+			if err != nil {
+				return err
+			}
+			return setAttrTfModel(attrNameModel, fieldModel, list)
+		case types.Set:
+			set, err := setSetAttrModel(collection, v)
+			if err != nil {
+				return err
+			}
+			return setAttrTfModel(attrNameModel, fieldModel, set)
+		}
+		return fmt.Errorf("unmarshal expects array for field %s", attrNameJSON)
 	default:
 		return fmt.Errorf("unmarshal not supported yet for type %T for field %s", v, attrNameJSON)
 	}
 }
 
-func setAttrModel(name string, field reflect.Value, val attr.Value) error {
+func setAttrTfModel(name string, field reflect.Value, val attr.Value) error {
 	obj := reflect.ValueOf(val)
 	if !field.Type().AssignableTo(obj.Type()) {
 		return fmt.Errorf("unmarshal can't assign value to model field %s", name)
 	}
 	field.Set(obj)
 	return nil
 }
+
+func setMapAttrModel(name string, value any, mapAttrs map[string]attr.Value, mapTypes map[string]attr.Type) error {
+	nameChildTf := xstrings.ToSnakeCase(name)
+	valueType, found := mapTypes[nameChildTf]
+	if !found {
+		return nil // skip attributes that are not in the model
+	}
+	newValue, err := getTfAttr(value, valueType, mapAttrs[nameChildTf])
+	if err != nil {
+		return err
+	}
+	if newValue != nil {
+		mapAttrs[nameChildTf] = newValue
+	}
+	return nil
+}
+
+func getTfAttr(value any, valueType attr.Type, oldValue attr.Value) (attr.Value, error) {
+	switch v := value.(type) {
+	case string:
+		if valueType == types.StringType {
+			return types.StringValue(v), nil
+		}
+		return nil, fmt.Errorf("unmarshal gets incorrect string for value: %v", v)
+	case bool:
+		if valueType == types.BoolType {
+			return types.BoolValue(v), nil
+		}
+		return nil, fmt.Errorf("unmarshal gets incorrect bool for value: %v", v)
+	case float64:
+		switch valueType {
+		case types.Int64Type:
+			return types.Int64Value(int64(v)), nil
+		case types.Float64Type:
+			return types.Float64Value(v), nil
+		}
+		return nil, fmt.Errorf("unmarshal gets incorrect number for value: %v", v)
+	case map[string]any:
+		obj, ok := oldValue.(types.Object)
+		if !ok {
+			return nil, fmt.Errorf("unmarshal gets incorrect object for value: %v", v)
+		}
+		objNew, err := setObjAttrModel(obj, v)
+		if err != nil {
+			return nil, err
+		}
+		return objNew, nil
+	case nil:
+		return nil, nil // skip nil values, no need to set anything
+	}
+	return nil, fmt.Errorf("unmarshal not supported yet for type %T", value)
+}
+
+func setObjAttrModel(obj types.Object, objJSON map[string]any) (attr.Value, error) {
+	mapAttrs, mapTypes, err := getObjAttrsAndTypes(obj)
+	if err != nil {
+		return nil, err
+	}
+	for nameChild, valueChild := range objJSON {
+		if err := setMapAttrModel(nameChild, valueChild, mapAttrs, mapTypes); err != nil {
+			return nil, err
+		}
+	}
+	objNew, diags := types.ObjectValue(obj.AttributeTypes(context.Background()), mapAttrs)
+	if diags.HasError() {
+		return nil, fmt.Errorf("unmarshal failed to convert map to object: %v", diags)
+	}
+	return objNew, nil
+}
+
+func setListAttrModel(list types.List, arrayJSON []any) (attr.Value, error) {
+	elmType := list.ElementType(context.Background())
+	elms, err := getCollectionElements(arrayJSON, elmType)
+	if err != nil {
+		return nil, err
+	}
+	listNew, diags := types.ListValue(elmType, elms)
+	if diags.HasError() {
+		return nil, fmt.Errorf("unmarshal failed to convert list to object: %v", diags)
+	}
+	return listNew, nil
+}
+
+func setSetAttrModel(set types.Set, arrayJSON []any) (attr.Value, error) {
+	elmType := set.ElementType(context.Background())
+	elms, err := getCollectionElements(arrayJSON, elmType)
+	if err != nil {
+		return nil, err
+	}
+	setNew, diags := types.SetValue(elmType, elms)
+	if diags.HasError() {
+		return nil, fmt.Errorf("unmarshal failed to convert set to object: %v", diags)
+	}
+	return setNew, nil
+}
+
+func getCollectionElements(arrayJSON []any, valueType attr.Type) ([]attr.Value, error) {
+	elms := make([]attr.Value, len(arrayJSON))
+	nullVal, err := getNullAttr(valueType)
+	if err != nil {
+		return nil, err
+	}
+	for i, item := range arrayJSON {
+		newValue, err := getTfAttr(item, valueType, nullVal)
+		if err != nil {
+			return nil, err
+		}
+		if newValue != nil {
+			elms[i] = newValue
+		}
+	}
+	return elms, nil
+}
+
+func getObjAttrsAndTypes(obj types.Object) (mapAttrs map[string]attr.Value, mapTypes map[string]attr.Type, err error) {
+	// mapTypes has all attributes, mapAttrs might not have them, e.g. in null or unknown objects
+	mapAttrs = obj.Attributes()
+	mapTypes = obj.AttributeTypes(context.Background())
+	for attrName, attrType := range mapTypes {
+		if _, found := mapAttrs[attrName]; found {
+			continue // skip attributes that are already set
+		}
+		nullVal, err := getNullAttr(attrType)
+		if err != nil {
+			return nil, nil, err
+		}
+		mapAttrs[attrName] = nullVal
+	}
+	return mapAttrs, mapTypes, nil
+}
+
+func getNullAttr(attrType attr.Type) (attr.Value, error) {
+	switch attrType {
+	case types.StringType:
+		return types.StringNull(), nil
+	case types.BoolType:
+		return types.BoolNull(), nil
+	case types.Int64Type:
+		return types.Int64Null(), nil
+	case types.Float64Type:
+		return types.Float64Null(), nil
+	default:
+		if objType, ok := attrType.(types.ObjectType); ok {
+			return types.ObjectNull(objType.AttributeTypes()), nil
+		}
+		return nil, fmt.Errorf("unmarshal to get null value not supported yet for type %T", attrType)
+	}
+}
+
+func convertUnknownToNull(valModel reflect.Value) {
+	for i := 0; i < valModel.NumField(); i++ {
+		field := valModel.Field(i)
+		if obj, ok := field.Interface().(types.Object); ok {
+			if obj.IsUnknown() && field.CanSet() {
+				field.Set(reflect.ValueOf(types.ObjectNull(obj.AttributeTypes(context.Background()))))
+			}
+		}
+	}
+}