add workflow logics

api/core/workflow/nodes/end/entities.py

@@ -0,0 +1,25 @@
+from enum import Enum
+
+
+class EndNodeOutputType(Enum):
+    """
+    END Node Output Types.
+
+    none, plain-text, structured
+    """
+    NONE = 'none'
+    PLAIN_TEXT = 'plain-text'
+    STRUCTURED = 'structured'
+
+    @classmethod
+    def value_of(cls, value: str) -> 'OutputType':
+        """
+        Get value of given output type.
+
+        :param value: output type value
+        :return: output type
+        """
+        for output_type in cls:
+            if output_type.value == value:
+                return output_type
+        raise ValueError(f'invalid output type value {value}')