Feature/service task part deux (#91)

src/spiffworkflow_backend/api.yml

@@ -847,6 +847,20 @@ paths:
                 items:
                   $ref: "#/components/schemas/Task"
 
+  /service_tasks:
+    get:
+      tags:
+        - Service Tasks
+      operationId: spiffworkflow_backend.routes.process_api_blueprint.service_tasks_show
+      summary: Gets all available service task connectors
+      responses:
+        "200":
+          description: All service task connectors
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ServiceTask"
+
   /tasks/{process_instance_id}/{task_id}:
     parameters:
       - name: task_id
@@ -1654,6 +1668,32 @@ components:
           type: number
           format: integer
           example: 5
+    ServiceTask:
+      properties:
+        items:
+          type: array
+          $ref: "#/components/schemas/ServiceTaskConnector"
+          readOnly: true
+    ServiceTaskConnector:
+      properties:
+        id:
+          type: string
+          example: xero/CreateInvoice
+        parameters:
+          type: array
+          $ref: "#/components/schemas/ServiceTaskOperatorParameter"
+          readOnly: true
+    ServiceTaskOperatorParameter:
+      properties:
+        id:
+          type: string
+          example: client_id
+        type:
+          type: string
+          example: str
+        required:
+          type: boolean
+          example: false
     GitRepo:
       properties:
         #        remote:

src/spiffworkflow_backend/config/default.py

@@ -34,3 +34,8 @@ OPEN_ID_CLIENT_SECRET_KEY = environ.get(
 SPIFFWORKFLOW_BACKEND_LOG_TO_FILE = (
     environ.get("SPIFFWORKFLOW_BACKEND_LOG_TO_FILE", default="false") == "true"
 )
+
+# service task connector proxy
+CONNECTOR_PROXY_URL = environ.get(
+    "CONNECTOR_PROXY_URL", default="http://localhost:7004"
+)

src/spiffworkflow_backend/routes/process_api_blueprint.py

@@ -54,6 +54,7 @@ from spiffworkflow_backend.services.process_instance_service import (
     ProcessInstanceService,
 )
 from spiffworkflow_backend.services.process_model_service import ProcessModelService
+from spiffworkflow_backend.services.service_task_service import ServiceTaskService
 from spiffworkflow_backend.services.spec_file_service import SpecFileService
 
 process_api_blueprint = Blueprint("process_api", __name__)
@@ -652,6 +653,16 @@ def process_instance_report_delete(
     return Response(json.dumps({"ok": True}), status=200, mimetype="application/json")
 
 
+def service_tasks_show() -> flask.wrappers.Response:
+    """service_tasks_show."""
+    available_connectors = ServiceTaskService.available_connectors()
+    print(available_connectors)
+
+    return Response(
+        json.dumps(available_connectors), status=200, mimetype="application/json"
+    )
+
+
 def process_instance_report_show(
     process_group_id: str,
     process_model_id: str,

src/spiffworkflow_backend/services/process_instance_processor.py

@@ -41,6 +41,7 @@ from SpiffWorkflow.spiff.serializer import ManualTaskConverter
 from SpiffWorkflow.spiff.serializer import NoneTaskConverter
 from SpiffWorkflow.spiff.serializer import ReceiveTaskConverter
 from SpiffWorkflow.spiff.serializer import SendTaskConverter
+from SpiffWorkflow.spiff.serializer import ServiceTaskConverter
 from SpiffWorkflow.spiff.serializer import StartEventConverter
 from SpiffWorkflow.spiff.serializer import SubWorkflowTaskConverter
 from SpiffWorkflow.spiff.serializer import TransactionSubprocessConverter
@@ -69,6 +70,7 @@ from spiffworkflow_backend.models.task_event import TaskEventModel
 from spiffworkflow_backend.models.user import UserModelSchema
 from spiffworkflow_backend.services.file_system_service import FileSystemService
 from spiffworkflow_backend.services.process_model_service import ProcessModelService
+from spiffworkflow_backend.services.service_task_service import ServiceTaskService
 from spiffworkflow_backend.services.spec_file_service import SpecFileService
 from spiffworkflow_backend.services.user_service import UserService
 
@@ -111,15 +113,21 @@ class CustomBpmnScriptEngine(PythonScriptEngine):  # type: ignore
                     "'%s', %s" % (expression, str(exception)),
                 ) from exception
 
-    def execute(self, task: SpiffTask, script: str) -> None:
+    def execute(
+        self, task: SpiffTask, script: str, external_methods: Any = None
+    ) -> None:
         """Execute."""
         try:
-            super().execute(task, script)
+            super().execute(task, script, external_methods)
         except WorkflowException as e:
             raise e
         except Exception as e:
             raise WorkflowTaskExecException(task, f" {script}, {e}", e) from e
 
+    def available_service_task_external_methods(self) -> Dict[str, Any]:
+        """Returns available service task external methods."""
+        return ServiceTaskService.scripting_additions()
+
 
 class MyCustomParser(BpmnDmnParser):  # type: ignore
     """A BPMN and DMN parser that can also parse spiffworkflow-specific extensions."""
@@ -150,6 +158,7 @@ class ProcessInstanceProcessor:
             NoneTaskConverter,
             ReceiveTaskConverter,
             SendTaskConverter,
+            ServiceTaskConverter,
             StartEventConverter,
             SubWorkflowTaskConverter,
             TransactionSubprocessConverter,

src/spiffworkflow_backend/services/service_task_service.py

@@ -0,0 +1,62 @@
+"""ServiceTask_service."""
+import json
+from typing import Any
+from typing import Dict
+
+import requests
+from flask import current_app
+
+
+def connector_proxy_url() -> Any:
+    """Returns the connector proxy url."""
+    return current_app.config["CONNECTOR_PROXY_URL"]
+
+
+class ServiceTaskDelegate:
+    """ServiceTaskDelegate."""
+
+    @staticmethod
+    def call_connector(
+        name: str, bpmn_params: Any
+    ) -> None:  # TODO what is the return/type
+        """Calls a connector via the configured proxy."""
+
+        def normalize_value(v: Any) -> Any:
+            value = v["value"]
+            secret_prefix = "secret:"  # noqa: S105
+            if value.startswith(secret_prefix):
+                key = value.removeprefix(secret_prefix)
+                # TODO replace with call to secret store
+                value = key
+            return value
+
+        params = {k: normalize_value(v) for k, v in bpmn_params.items()}
+        proxied_response = requests.get(f"{connector_proxy_url()}/v1/do/{name}", params)
+
+        if proxied_response.status_code != 200:
+            print("got error from connector proxy")
+
+
+class ServiceTaskService:
+    """ServiceTaskService."""
+
+    @staticmethod
+    def available_connectors() -> Any:
+        """Returns a list of available connectors."""
+        try:
+            print(connector_proxy_url)
+            response = requests.get(f"{connector_proxy_url()}/v1/commands")
+
+            if response.status_code != 200:
+                return []
+
+            parsed_response = json.loads(response.text)
+            return parsed_response
+        except Exception as e:
+            print(e)
+            return []
+
+    @staticmethod
+    def scripting_additions() -> Dict[str, Any]:
+        """Allows the ServiceTaskDelegate to be available to script engine instances."""
+        return {"ServiceTaskDelegate": ServiceTaskDelegate}