Feat: conversation variable & variable assigner node (#7222)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: Joel <iamjoel007@gmail.com>
Co-authored-by: -LAN- <laipz8200@outlook.com>

api/controllers/console/app/conversation_variables.py

@@ -0,0 +1,61 @@
+from flask_restful import Resource, marshal_with, reqparse
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from controllers.console import api
+from controllers.console.app.wraps import get_app_model
+from controllers.console.setup import setup_required
+from controllers.console.wraps import account_initialization_required
+from extensions.ext_database import db
+from fields.conversation_variable_fields import paginated_conversation_variable_fields
+from libs.login import login_required
+from models import ConversationVariable
+from models.model import AppMode
+
+
+class ConversationVariablesApi(Resource):
+    @setup_required
+    @login_required
+    @account_initialization_required
+    @get_app_model(mode=AppMode.ADVANCED_CHAT)
+    @marshal_with(paginated_conversation_variable_fields)
+    def get(self, app_model):
+        parser = reqparse.RequestParser()
+        parser.add_argument('conversation_id', type=str, location='args')
+        args = parser.parse_args()
+
+        stmt = (
+            select(ConversationVariable)
+            .where(ConversationVariable.app_id == app_model.id)
+            .order_by(ConversationVariable.created_at)
+        )
+        if args['conversation_id']:
+            stmt = stmt.where(ConversationVariable.conversation_id == args['conversation_id'])
+        else:
+            raise ValueError('conversation_id is required')
+
+        # NOTE: This is a temporary solution to avoid performance issues.
+        page = 1
+        page_size = 100
+        stmt = stmt.limit(page_size).offset((page - 1) * page_size)
+
+        with Session(db.engine) as session:
+            rows = session.scalars(stmt).all()
+
+        return {
+            'page': page,
+            'limit': page_size,
+            'total': len(rows),
+            'has_more': False,
+            'data': [
+                {
+                    'created_at': row.created_at,
+                    'updated_at': row.updated_at,
+                    **row.to_variable().model_dump(),
+                }
+                for row in rows
+            ],
+        }
+
+
+api.add_resource(ConversationVariablesApi, '/apps/<uuid:app_id>/conversation-variables')