From 47bb9ab45aaf5fd267c9352f61884b5db964fb64 Mon Sep 17 00:00:00 2001
From: Denis Arh <denis.arh@gmail.com>
Date: Sun, 19 Apr 2020 10:15:15 +0200
Subject: [PATCH] Support "final" flag for KV

This enables us to store structure as JSON under a specific
(final) key
---
 pkg/settings/kv_decoder.go      | 58 ++++++++++++++++++---------------
 pkg/settings/kv_decoder_test.go | 32 ++++++++++++++++++
 2 files changed, 64 insertions(+), 26 deletions(-)

diff --git a/pkg/settings/kv_decoder.go b/pkg/settings/kv_decoder.go
index 7cf77d08a..a054324dc 100644
--- a/pkg/settings/kv_decoder.go
+++ b/pkg/settings/kv_decoder.go
@@ -48,7 +48,10 @@ func DecodeKV(kv KV, dst interface{}, pp ...string) (err error) {
 	length := valueOf.NumField()
 
 	for i := 0; i < length; i++ {
-		var structField = valueOf.Field(i)
+		var (
+			structField = valueOf.Field(i)
+			tags        = make(map[string]bool)
+		)
 
 		if !structField.CanSet() {
 			continue
@@ -80,6 +83,7 @@ func DecodeKV(kv KV, dst interface{}, pp ...string) (err error) {
 
 			for f := 1; f < len(tagFlags); f++ {
 				// @todo resolve i18n and other flags...
+				tags[tagFlags[f]] = true
 			}
 		}
 
@@ -102,36 +106,38 @@ func DecodeKV(kv KV, dst interface{}, pp ...string) (err error) {
 			}
 		}
 
-		// Handles structs
-		//
-		// It calls DecodeKV recursively
-		if structField.Kind() == reflect.Struct {
-			if err = DecodeKV(kv.Filter(key), structValue, key); err != nil {
-				return
-			}
-
-			continue
-		}
-
-		// Handles map values
-		if structField.Kind() == reflect.Map {
-			if structField.IsNil() {
-				// allocate new map
-				structField.Set(reflect.MakeMap(structField.Type()))
-			}
-
-			// cut KV key prefix and use the rest for the map key
-			for k, val := range kv.CutPrefix(key + ".") {
-				mapValue := reflect.New(structField.Type().Elem())
-				err = val.Unmarshal(mapValue.Interface())
-				if err != nil {
+		if !tags["final"] {
+			// Handles structs
+			//
+			// It calls DecodeKV recursively
+			if structField.Kind() == reflect.Struct {
+				if err = DecodeKV(kv.Filter(key), structValue, key); err != nil {
 					return
 				}
 
-				structField.SetMapIndex(reflect.ValueOf(k), mapValue.Elem())
+				continue
 			}
 
-			continue
+			// Handles map values
+			if structField.Kind() == reflect.Map {
+				if structField.IsNil() {
+					// allocate new map
+					structField.Set(reflect.MakeMap(structField.Type()))
+				}
+
+				// cut KV key prefix and use the rest for the map key
+				for k, val := range kv.CutPrefix(key + ".") {
+					mapValue := reflect.New(structField.Type().Elem())
+					err = val.Unmarshal(mapValue.Interface())
+					if err != nil {
+						return
+					}
+
+					structField.SetMapIndex(reflect.ValueOf(k), mapValue.Elem())
+				}
+
+				continue
+			}
 		}
 
 		// Native type
diff --git a/pkg/settings/kv_decoder_test.go b/pkg/settings/kv_decoder_test.go
index 47558fb51..96fd282b8 100644
--- a/pkg/settings/kv_decoder_test.go
+++ b/pkg/settings/kv_decoder_test.go
@@ -1,6 +1,7 @@
 package settings
 
 import (
+	"github.com/davecgh/go-spew/spew"
 	"testing"
 
 	"github.com/jmoiron/sqlx/types"
@@ -132,3 +133,34 @@ func TestDecodeHandler(t *testing.T) {
 	require.Equal(t, 1, aux.Foo.set)
 	require.Equal(t, 1, aux.Bar.set)
 }
+
+func TestDecodeKV_WithFinalTag(t *testing.T) {
+	type (
+		dst struct {
+			NotFinal struct {
+				Foo string
+				Sub struct {
+					SubFoo int
+				}
+			}
+
+			IsFinal struct {
+				Foo string
+				Sub struct {
+					SubFoo int
+				}
+			} `kv:",final"`
+		}
+	)
+
+	var (
+		aux = dst{}
+		kv  = KV{
+			"notFinal.foo":        types.JSONText(`"42"`),
+			"notFinal.sub.subFoo": types.JSONText(`42`),
+			"isFinal":             types.JSONText(`{"Foo":"final42","Sub":{"SubFoo":42}}`),
+		}
+	)
+
+	spew.Dump(DecodeKV(kv, &aux), aux)
+}