1 files changed, 115 insertions, 0 deletions
diff --git a/model/node.go b/model/node.go
new file mode 100644
index 0000000..1483eaf
--- /dev/null
+++ b/model/node.go
@@ -0,0 +1,115 @@
+package model
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+)
+
+// Node of JSON tree
+type Node struct {
+	Type         NodeType
+	stringValue  string
+	numberValue  float64
+	objectValue  NodeObjectValue
+	arrayValue   NodeArrayValue
+	booleanValue bool
+}
+
+// NewNode creates new node from value
+func NewNode(value any) *Node {
+	n := new(Node)
+	n.SetValue(value)
+	return n
+}
+
+// Value returns value of node
+func (n *Node) Value() any {
+	switch n.Type {
+	case StringNode:
+		return n.stringValue
+	case NumberNode:
+		return n.numberValue
+	case ObjectNode:
+		return n.objectValue
+	case ArrayNode:
+		return n.arrayValue
+	case BooleanNode:
+		return n.booleanValue
+	default:
+		return nil
+	}
+}
+
+// SetValue to node
+func (n *Node) SetValue(value any) {
+	switch value := value.(type) {
+	case string:
+		n.Type = StringNode
+		n.stringValue = value
+	case float64:
+		n.Type = NumberNode
+		n.numberValue = value
+	case int:
+		n.Type = NumberNode
+		n.numberValue = float64(value)
+	case NodeObjectValue:
+		n.Type = ObjectNode
+		n.objectValue = value
+	case NodeArrayValue:
+		n.Type = ArrayNode
+		n.arrayValue = value
+	case bool:
+		n.Type = BooleanNode
+		n.booleanValue = value
+	default:
+		n.Type = NullNode
+	}
+}
+
+// MarshalJSON to []byte
+func (n *Node) MarshalJSON() ([]byte, error) {
+	switch n.Type {
+	case StringNode:
+		return []byte(`"` + n.stringValue + `"`), nil
+	case NumberNode:
+		return []byte(strconv.FormatFloat(n.numberValue, 'g', -1, 64)), nil
+	case ObjectNode:
+		result := make([][]byte, 0, len(n.objectValue))
+		for k, v := range n.objectValue {
+			b, err := v.MarshalJSON()
+			if err != nil {
+				return nil, err
+			}
+			result = append(result, []byte(fmt.Sprintf("\"%s\": %s", k, b)))
+		}
+		return bytes.Join(
+			[][]byte{
+				[]byte("{"),
+				bytes.Join(result, []byte(", ")),
+				[]byte("}"),
+			}, []byte("")), nil
+	case ArrayNode:
+		result := make([][]byte, 0, len(n.arrayValue))
+		for _, v := range n.arrayValue {
+			b, err := v.MarshalJSON()
+			if err != nil {
+				return nil, err
+			}
+			result = append(result, b)
+		}
+		return bytes.Join(
+			[][]byte{
+				[]byte("["),
+				bytes.Join(result, []byte(", ")),
+				[]byte("]"),
+			}, []byte("")), nil
+	case BooleanNode:
+		if n.booleanValue {
+			return []byte("true"), nil
+		}
+		return []byte("false"), nil
+	default:
+		return []byte("null"), nil
+	}
+}