From 7ec2533b7ad94052ab08198a6343a51ff3ec168b Mon Sep 17 00:00:00 2001
From: dudaodong <lanliddd.2007@163.com>
Date: Mon, 19 Feb 2024 13:50:06 +0800
Subject: [PATCH] feat: add MapToStruct

---
 maputil/map.go      | 77 +++++++++++++++++++++++++++++++++++++++++++++
 maputil/map_test.go | 39 +++++++++++++++++++++++
 2 files changed, 116 insertions(+)

diff --git a/maputil/map.go b/maputil/map.go
index a445121..008f641 100644
--- a/maputil/map.go
+++ b/maputil/map.go
@@ -5,6 +5,7 @@
 package maputil
 
 import (
+	"fmt"
 	"reflect"
 
 	"github.com/duke-git/lancet/v2/slice"
@@ -303,3 +304,79 @@ func HasKey[K comparable, V any](m map[K]V, key K) bool {
 	_, haskey := m[key]
 	return haskey
 }
+
+// MapToStruct converts map to struct
+// Play: todo
+func MapToStruct(m map[string]interface{}, structObj interface{}) error {
+
+	for k, v := range m {
+		err := setStructField(structObj, k, v)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func setStructField(structObj any, fieldName string, fieldValue any) error {
+	structVal := reflect.ValueOf(structObj).Elem()
+
+	fName := getFieldNameByJsonTag(structObj, fieldName)
+	if fName == "" {
+		return fmt.Errorf("Struct field json tag don't match map key : %s in obj", fieldName)
+	}
+
+	fieldVal := structVal.FieldByName(fName)
+
+	if !fieldVal.IsValid() {
+		return fmt.Errorf("No such field: %s in obj", fieldName)
+	}
+
+	if !fieldVal.CanSet() {
+		return fmt.Errorf("Cannot set %s field value", fieldName)
+	}
+
+	val := reflect.ValueOf(fieldValue)
+
+	if fieldVal.Type() != val.Type() {
+
+		if m, ok := fieldValue.(map[string]interface{}); ok {
+
+			if fieldVal.Kind() == reflect.Struct {
+				return MapToStruct(m, fieldVal.Addr().Interface())
+			}
+
+			if fieldVal.Kind() == reflect.Ptr && fieldVal.Type().Elem().Kind() == reflect.Struct {
+				if fieldVal.IsNil() {
+					fieldVal.Set(reflect.New(fieldVal.Type().Elem()))
+				}
+
+				return MapToStruct(m, fieldVal.Interface())
+			}
+
+		}
+
+		return fmt.Errorf("Map value type don't match struct field type")
+	}
+
+	fieldVal.Set(val)
+
+	return nil
+}
+
+func getFieldNameByJsonTag(structObj any, jsonTag string) string {
+	s := reflect.TypeOf(structObj).Elem()
+
+	for i := 0; i < s.NumField(); i++ {
+		field := s.Field(i)
+		tag := field.Tag
+		name := tag.Get("json")
+
+		if name == jsonTag {
+			return field.Name
+		}
+	}
+
+	return ""
+}
diff --git a/maputil/map_test.go b/maputil/map_test.go
index 843d510..7753637 100644
--- a/maputil/map_test.go
+++ b/maputil/map_test.go
@@ -472,3 +472,42 @@ func TestHasKey(t *testing.T) {
 	assert.Equal(true, HasKey(m, "a"))
 	assert.Equal(false, HasKey(m, "c"))
 }
+
+func TestMapToStruct(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestMapToStruct")
+
+	type (
+		Person struct {
+			Name  string   `json:"name"`
+			Age   int      `json:"age"`
+			Phone string   `json:"phone"`
+			Addr  *Address `json:"address"`
+		}
+
+		Address struct {
+			Street string `json:"street"`
+			Number int    `json:"number"`
+		}
+	)
+
+	m := map[string]interface{}{
+		"name":  "Nothin",
+		"age":   28,
+		"phone": "123456789",
+		"address": map[string]interface{}{
+			"street": "test",
+			"number": 1,
+		},
+	}
+
+	var p Person
+	err := MapToStruct(m, &p)
+	assert.IsNil(err)
+	assert.Equal(m["name"], p.Name)
+	assert.Equal(m["age"], p.Age)
+	assert.Equal(m["phone"], p.Phone)
+	assert.Equal("test", p.Addr.Street)
+	assert.Equal(1, p.Addr.Number)
+}