From 979066856b7bff543a7a6901e5ae94c372160f73 Mon Sep 17 00:00:00 2001
From: Hitalo Souza <63821277+enghitalo@users.noreply.github.com>
Date: Fri, 24 Mar 2023 08:45:26 -0300
Subject: [PATCH] json2: encode map (#16928)

---
 vlib/x/json2/encode_struct_test.v             |  21 ++
 vlib/x/json2/encoder.v                        |  32 ++-
 vlib/x/json2/json2.v                          | 202 +++++++++---------
 .../json_test.v                               |  57 ++++-
 .../json_todo_test.vv                         |  25 +++
 5 files changed, 232 insertions(+), 105 deletions(-)

diff --git a/vlib/x/json2/encode_struct_test.v b/vlib/x/json2/encode_struct_test.v
index 3aaabcdd02..bcc942a6f9 100644
--- a/vlib/x/json2/encode_struct_test.v
+++ b/vlib/x/json2/encode_struct_test.v
@@ -252,3 +252,24 @@ fn test_sumtypes() {
 		}
 	}) == '{"val":{"val":1}}'
 }
+
+fn test_maps() {
+	assert json.encode(StructType[map[string]map[string]int]{}) == '{"val":{}}'
+	assert json.encode(StructType[map[string]string]{
+		val: {
+			'1': '1'
+		}
+	}) == '{"val":{"1":"1"}}'
+	assert json.encode(StructType[map[string]int]{
+		val: {
+			'1': 1
+		}
+	}) == '{"val":{"1":1}}'
+	// assert json.encode(StructType[map[string]map[string]int]{
+	// 	val: {
+	// 		'a': {
+	// 			'1': 1
+	// 		}
+	// 	}
+	// }) == '{"val":{"a":{"1":1}}}'
+}
diff --git a/vlib/x/json2/encoder.v b/vlib/x/json2/encoder.v
index 2f4a7f99b5..94356df97c 100644
--- a/vlib/x/json2/encoder.v
+++ b/vlib/x/json2/encoder.v
@@ -39,6 +39,10 @@ const quote_bytes = [u8(`"`)]
 const escaped_chars = [(r'\b').bytes(), (r'\f').bytes(), (r'\n').bytes(),
 	(r'\r').bytes(), (r'\t').bytes()]
 
+const curly_open = [u8(`{`)]
+
+const curly_close = [u8(`}`)]
+
 // encode_value encodes a value to the specific writer.
 pub fn (e &Encoder) encode_value[T](val T, mut wr io.Writer) ! {
 	e.encode_value_with_level[T](val, 1, mut wr)!
@@ -83,7 +87,7 @@ fn (e &Encoder) encode_any(val Any, level int, mut wr io.Writer) ! {
 			wr.write(json2.zero_in_bytes)!
 		}
 		map[string]Any {
-			wr.write([u8(`{`)])!
+			wr.write(json2.curly_open)!
 			mut i := 0
 			for k, v in val {
 				e.encode_newline(level, mut wr)!
@@ -99,7 +103,7 @@ fn (e &Encoder) encode_any(val Any, level int, mut wr io.Writer) ! {
 				i++
 			}
 			e.encode_newline(level - 1, mut wr)!
-			wr.write([u8(`}`)])!
+			wr.write(json2.curly_close)!
 		}
 		[]Any {
 			wr.write([u8(`[`)])!
@@ -128,6 +132,8 @@ fn (e &Encoder) encode_value_with_level[T](val T, level int, mut wr io.Writer) !
 	} $else $if T is map[string]Any {
 		// weird quirk but val is destructured immediately to Any
 		e.encode_any(val, level, mut wr)!
+	} $else $if T is $map {
+		// FIXME - `e.encode_struct` can not encode `map[string]map[string]int` type
 	} $else $if T is []Any {
 		e.encode_any(val, level, mut wr)!
 	} $else $if T is Encodable {
@@ -145,7 +151,7 @@ fn (e &Encoder) encode_value_with_level[T](val T, level int, mut wr io.Writer) !
 }
 
 fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
-	wr.write([u8(`{`)])!
+	wr.write(json2.curly_open)!
 	mut i := 0
 	mut fields_len := 0
 	$for field in U.fields {
@@ -254,6 +260,24 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
 				// e.encode_array(value, level + 1, mut wr)! // FIXME - error: could not infer generic type `U` in call to `encode_array`
 			} $else $if field.typ is $struct {
 				e.encode_struct(value, level + 1, mut wr)!
+			} $else $if field.is_map {
+				wr.write(json2.curly_open)!
+				mut idx := 0
+				for k, v in value {
+					e.encode_newline(level, mut wr)!
+					e.encode_string(k.str(), mut wr)!
+					wr.write(json2.colon_bytes)!
+					if e.newline != 0 {
+						wr.write(json2.space_bytes)!
+					}
+					e.encode_value_with_level(v, level + 1, mut wr)!
+					if idx < value.len - 1 {
+						wr.write(json2.comma_bytes)!
+					}
+					idx++
+				}
+				e.encode_newline(level, mut wr)!
+				wr.write(json2.curly_close)!
 			} $else $if field.is_enum {
 				// TODO - replace for `field.typ is $enum`
 				wr.write(int(val.$(field.name)).str().bytes())!
@@ -356,7 +380,7 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
 		}
 	}
 	e.encode_newline(level - 1, mut wr)!
-	wr.write([u8(`}`)])!
+	wr.write(json2.curly_close)!
 }
 
 fn (e &Encoder) encode_array[U](val []U, level int, mut wr io.Writer) ! {
diff --git a/vlib/x/json2/json2.v b/vlib/x/json2/json2.v
index 5c0f5a37f0..9ebdeead94 100644
--- a/vlib/x/json2/json2.v
+++ b/vlib/x/json2/json2.v
@@ -20,115 +20,119 @@ pub fn fast_raw_decode(src string) !Any {
 
 // decode is a generic function that decodes a JSON string into the target type.
 pub fn decode[T](src string) !T {
-	res := raw_decode(src)!.as_map()
 	mut typ := T{}
-	$for field in T.fields {
-		mut json_name := field.name
-		for attr in field.attrs {
-			if attr.contains('json: ') {
-				json_name = attr.replace('json: ', '')
-				break
+	$if T is $struct {
+		res := raw_decode(src)!.as_map()
+		$for field in T.fields {
+			mut json_name := field.name
+			for attr in field.attrs {
+				if attr.contains('json: ') {
+					json_name = attr.replace('json: ', '')
+					break
+				}
 			}
-		}
 
-		$if field.is_enum {
-			typ.$(field.name) = if key := res[field.name] {
-				key.int()
-			} else {
-				res[json_name]!.int()
-			}
-		} $else $if field.typ is u8 {
-			typ.$(field.name) = res[json_name]!.u64()
-		} $else $if field.typ is u16 {
-			typ.$(field.name) = res[json_name]!.u64()
-		} $else $if field.typ is u32 {
-			typ.$(field.name) = res[json_name]!.u64()
-		} $else $if field.typ is u64 {
-			typ.$(field.name) = res[json_name]!.u64()
-		} $else $if field.typ is int {
-			typ.$(field.name) = res[json_name]!.int()
-		} $else $if field.typ is i8 {
-			typ.$(field.name) = res[json_name]!.int()
-		} $else $if field.typ is i16 {
-			typ.$(field.name) = res[json_name]!.int()
-		} $else $if field.typ is i32 {
-			typ.$(field.name) = i32(res[field.name]!.int())
-		} $else $if field.typ is i64 {
-			typ.$(field.name) = res[json_name]!.i64()
-		} $else $if field.typ is ?u8 {
-			if json_name in res {
-				typ.$(field.name) = ?u8(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?i8 {
-			if json_name in res {
-				typ.$(field.name) = ?i8(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?u16 {
-			if json_name in res {
-				typ.$(field.name) = ?u16(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?i16 {
-			if json_name in res {
-				typ.$(field.name) = ?i16(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?u32 {
-			if json_name in res {
-				typ.$(field.name) = ?u32(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?i32 {
-			if json_name in res {
-				typ.$(field.name) = ?i32(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?u64 {
-			if json_name in res {
-				typ.$(field.name) = ?u64(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?i64 {
-			if json_name in res {
-				typ.$(field.name) = ?i64(res[json_name]!.i64())
-			}
-		} $else $if field.typ is ?int {
-			if json_name in res {
-				typ.$(field.name) = ?int(res[json_name]!.i64())
-			}
-		} $else $if field.typ is f32 {
-			typ.$(field.name) = res[json_name]!.f32()
-		} $else $if field.typ is ?f32 {
-			if json_name in res {
+			$if field.is_enum {
+				typ.$(field.name) = if key := res[field.name] {
+					key.int()
+				} else {
+					res[json_name]!.int()
+				}
+			} $else $if field.typ is u8 {
+				typ.$(field.name) = res[json_name]!.u64()
+			} $else $if field.typ is u16 {
+				typ.$(field.name) = res[json_name]!.u64()
+			} $else $if field.typ is u32 {
+				typ.$(field.name) = res[json_name]!.u64()
+			} $else $if field.typ is u64 {
+				typ.$(field.name) = res[json_name]!.u64()
+			} $else $if field.typ is int {
+				typ.$(field.name) = res[json_name]!.int()
+			} $else $if field.typ is i8 {
+				typ.$(field.name) = res[json_name]!.int()
+			} $else $if field.typ is i16 {
+				typ.$(field.name) = res[json_name]!.int()
+			} $else $if field.typ is i32 {
+				typ.$(field.name) = i32(res[field.name]!.int())
+			} $else $if field.typ is i64 {
+				typ.$(field.name) = res[json_name]!.i64()
+			} $else $if field.typ is ?u8 {
+				if json_name in res {
+					typ.$(field.name) = ?u8(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?i8 {
+				if json_name in res {
+					typ.$(field.name) = ?i8(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?u16 {
+				if json_name in res {
+					typ.$(field.name) = ?u16(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?i16 {
+				if json_name in res {
+					typ.$(field.name) = ?i16(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?u32 {
+				if json_name in res {
+					typ.$(field.name) = ?u32(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?i32 {
+				if json_name in res {
+					typ.$(field.name) = ?i32(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?u64 {
+				if json_name in res {
+					typ.$(field.name) = ?u64(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?i64 {
+				if json_name in res {
+					typ.$(field.name) = ?i64(res[json_name]!.i64())
+				}
+			} $else $if field.typ is ?int {
+				if json_name in res {
+					typ.$(field.name) = ?int(res[json_name]!.i64())
+				}
+			} $else $if field.typ is f32 {
 				typ.$(field.name) = res[json_name]!.f32()
-			}
-		} $else $if field.typ is f64 {
-			typ.$(field.name) = res[json_name]!.f64()
-		} $else $if field.typ is ?f64 {
-			if json_name in res {
+			} $else $if field.typ is ?f32 {
+				if json_name in res {
+					typ.$(field.name) = res[json_name]!.f32()
+				}
+			} $else $if field.typ is f64 {
 				typ.$(field.name) = res[json_name]!.f64()
-			}
-		} $else $if field.typ is bool {
-			typ.$(field.name) = res[json_name]!.bool()
-		} $else $if field.typ is ?bool {
-			if json_name in res {
+			} $else $if field.typ is ?f64 {
+				if json_name in res {
+					typ.$(field.name) = res[json_name]!.f64()
+				}
+			} $else $if field.typ is bool {
 				typ.$(field.name) = res[json_name]!.bool()
-			}
-		} $else $if field.typ is string {
-			typ.$(field.name) = res[json_name]!.str()
-		} $else $if field.typ is ?string {
-			if json_name in res {
+			} $else $if field.typ is ?bool {
+				if json_name in res {
+					typ.$(field.name) = res[json_name]!.bool()
+				}
+			} $else $if field.typ is string {
 				typ.$(field.name) = res[json_name]!.str()
-			}
-		} $else $if field.typ is time.Time {
-			typ.$(field.name) = res[field.name]!.to_time()!
-		} $else $if field.typ is ?time.Time {
-			if json_name in res {
+			} $else $if field.typ is ?string {
+				if json_name in res {
+					typ.$(field.name) = res[json_name]!.str()
+				}
+			} $else $if field.typ is time.Time {
 				typ.$(field.name) = res[field.name]!.to_time()!
+			} $else $if field.typ is ?time.Time {
+				if json_name in res {
+					typ.$(field.name) = res[field.name]!.to_time()!
+				}
+			} $else $if field.is_array {
+				// typ.$(field.name) = res[field.name]!.arr()
+			} $else $if field.is_struct {
+			} $else $if field.is_alias {
+			} $else $if field.is_map {
+			} $else {
+				return error("The type of `${field.name}` can't be decoded. Please open an issue at https://github.com/vlang/v/issues/new/choose")
 			}
-		} $else $if field.is_array {
-			// typ.$(field.name) = res[field.name]!.arr()
-		} $else $if field.is_struct {
-		} $else $if field.is_alias {
-		} $else $if field.is_map {
-		} $else {
-			return error("The type of `${field.name}` can't be decoded. Please open an issue at https://github.com/vlang/v/issues/new/choose")
 		}
+	} $else $if T is $map {
+		return error('Decode map is not allowed for now')
 	}
 	return typ
 }
diff --git a/vlib/x/json2/json_module_compatibility_test/json_test.v b/vlib/x/json2/json_module_compatibility_test/json_test.v
index 48ea1f6b92..7a455afdf4 100644
--- a/vlib/x/json2/json_module_compatibility_test/json_test.v
+++ b/vlib/x/json2/json_module_compatibility_test/json_test.v
@@ -61,8 +61,8 @@ mut:
 	reg_date time.Time
 }
 
-// // User struct needs to be `pub mut` for now in order to access and manipulate values
-struct User {
+// User struct needs to be `pub mut` for now in order to access and manipulate values
+pub struct User {
 pub mut:
 	age           int
 	nums          []int
@@ -264,3 +264,56 @@ fn test_encode_alias_field() {
 	})
 	assert s == '{"sub":{"a":1}}'
 }
+
+pub struct City {
+mut:
+	name string
+}
+
+pub struct Country {
+mut:
+	cities []City
+	name   string
+}
+
+struct Data {
+mut:
+	countries []Country
+	users     map[string]User
+}
+
+fn test_nested_type() {
+	data_expected := '{"countries":[{"cities":[{"name":"London"},{"name":"Manchester"}],"name":"UK"},{"cities":[{"name":"Donlon"},{"name":"Termanches"}],"name":"KU"}],"users":{"Foo":{"age":10,"nums":[1,2,3],"lastName":"Johnson","IsRegistered":true,"type":0,"pet_animals":"little foo"},"Boo":{"age":20,"nums":[5,3,1],"lastName":"Smith","IsRegistered":false,"type":4,"pet_animals":"little boo"}}}'
+	data := Data{
+		countries: [
+			Country{
+				name: 'UK'
+				cities: [City{'London'}, City{'Manchester'}]
+			},
+			Country{
+				name: 'KU'
+				cities: [City{'Donlon'}, City{'Termanches'}]
+			},
+		]
+		users: {
+			'Foo': User{
+				age: 10
+				nums: [1, 2, 3]
+				last_name: 'Johnson'
+				is_registered: true
+				typ: 0
+				pets: 'little foo'
+			}
+			'Boo': User{
+				age: 20
+				nums: [5, 3, 1]
+				last_name: 'Smith'
+				is_registered: false
+				typ: 4
+				pets: 'little boo'
+			}
+		}
+	}
+	out := json.encode(data)
+	assert out == data_expected
+}
diff --git a/vlib/x/json2/json_module_compatibility_test/json_todo_test.vv b/vlib/x/json2/json_module_compatibility_test/json_todo_test.vv
index 75896efe7a..8fd258222a 100644
--- a/vlib/x/json2/json_module_compatibility_test/json_todo_test.vv
+++ b/vlib/x/json2/json_module_compatibility_test/json_todo_test.vv
@@ -112,6 +112,31 @@ pub mut:
 	pets          string [json: 'pet_animals'; raw]
 }
 
+fn test_parse_user() {
+	s := '{"age": 10, "nums": [1,2,3], "type": 1, "lastName": "Johnson", "IsRegistered": true, "pet_animals": {"name": "Bob", "animal": "Dog"}}'
+	u2 := json.decode[User2](s)!
+	u := json.decode[User](s)!
+	assert u.age == 10
+	assert u.last_name == 'Johnson'
+	assert u.is_registered == true
+	assert u.nums.len == 3
+	assert u.nums[0] == 1
+	assert u.nums[1] == 2
+	assert u.nums[2] == 3
+	assert u.typ == 1
+	assert u.pets == '{"name":"Bob","animal":"Dog"}'
+}
+
+//! BUGFIX - .from_json(res)
+fn test_encode_decode_time() {
+	user := User2{
+		age: 25
+		reg_date: time.new_time(year: 2020, month: 12, day: 22, hour: 7, minute: 23)
+	}
+	s := json.encode(user)
+	assert s.contains('"reg_date":1608621780')
+	user2 := json.decode[User2](s)!
+	assert user2.reg_date.str() == '2020-12-22 07:23:00'
 struct City {
 	name string
 }