dify/api/services/workflow_service.py

import json
import time
from datetime import datetime, timezone
from typing import Optional

from core.app.apps.advanced_chat.app_config_manager import AdvancedChatAppConfigManager
from core.app.apps.workflow.app_config_manager import WorkflowAppConfigManager
from core.model_runtime.utils.encoders import jsonable_encoder
from core.workflow.entities.node_entities import NodeType
from core.workflow.errors import WorkflowNodeRunFailedError
from core.workflow.workflow_engine_manager import WorkflowEngineManager
from events.app_event import app_draft_workflow_was_synced, app_published_workflow_was_updated
from extensions.ext_database import db
from models.account import Account
from models.model import App, AppMode
from models.workflow import (
    CreatedByRole,
    Workflow,
    WorkflowNodeExecution,
    WorkflowNodeExecutionStatus,
    WorkflowNodeExecutionTriggeredFrom,
    WorkflowType,
)
from services.errors.app import WorkflowHashNotEqualError
from services.workflow.workflow_converter import WorkflowConverter


class WorkflowService:
    """
    Workflow Service
    """

    def get_draft_workflow(self, app_model: App) -> Optional[Workflow]:
        """
        Get draft workflow
        """
        # fetch draft workflow by app_model
        workflow = db.session.query(Workflow).filter(
            Workflow.tenant_id == app_model.tenant_id,
            Workflow.app_id == app_model.id,
            Workflow.version == 'draft'
        ).first()

        # return draft workflow
        return workflow

    def get_published_workflow(self, app_model: App) -> Optional[Workflow]:
        """
        Get published workflow
        """

        if not app_model.workflow_id:
            return None

        # fetch published workflow by workflow_id
        workflow = db.session.query(Workflow).filter(
            Workflow.tenant_id == app_model.tenant_id,
            Workflow.app_id == app_model.id,
            Workflow.id == app_model.workflow_id
        ).first()

        return workflow

    def sync_draft_workflow(self, app_model: App,
                            graph: dict,
                            features: dict,
                            unique_hash: Optional[str],
                            account: Account) -> Workflow:
        """
        Sync draft workflow
        :raises WorkflowHashNotEqualError
        """
        # fetch draft workflow by app_model
        workflow = self.get_draft_workflow(app_model=app_model)

        if workflow:
            # validate unique hash
            if workflow.unique_hash != unique_hash:
                raise WorkflowHashNotEqualError()

        # validate features structure
        self.validate_features_structure(
            app_model=app_model,
            features=features
        )

        # create draft workflow if not found
        if not workflow:
            workflow = Workflow(
                tenant_id=app_model.tenant_id,
                app_id=app_model.id,
                type=WorkflowType.from_app_mode(app_model.mode).value,
                version='draft',
                graph=json.dumps(graph),
                features=json.dumps(features),
                created_by=account.id
            )
            db.session.add(workflow)
        # update draft workflow if found
        else:
            workflow.graph = json.dumps(graph)
            workflow.features = json.dumps(features)
            workflow.updated_by = account.id
            workflow.updated_at = datetime.now(timezone.utc).replace(tzinfo=None)

        # commit db session changes
        db.session.commit()

        # trigger app workflow events
        app_draft_workflow_was_synced.send(app_model, synced_draft_workflow=workflow)

        # return draft workflow
        return workflow

    def publish_workflow(self, app_model: App,
                         account: Account,
                         draft_workflow: Optional[Workflow] = None) -> Workflow:
        """
        Publish workflow from draft

        :param app_model: App instance
        :param account: Account instance
        :param draft_workflow: Workflow instance
        """
        if not draft_workflow:
            # fetch draft workflow by app_model
            draft_workflow = self.get_draft_workflow(app_model=app_model)

        if not draft_workflow:
            raise ValueError('No valid workflow found.')

        # create new workflow
        workflow = Workflow(
            tenant_id=app_model.tenant_id,
            app_id=app_model.id,
            type=draft_workflow.type,
            version=str(datetime.now(timezone.utc).replace(tzinfo=None)),
            graph=draft_workflow.graph,
            features=draft_workflow.features,
            created_by=account.id
        )

        # commit db session changes
        db.session.add(workflow)
        db.session.flush()
        db.session.commit()

        app_model.workflow_id = workflow.id
        db.session.commit()

        # trigger app workflow events
        app_published_workflow_was_updated.send(app_model, published_workflow=workflow)

        # return new workflow
        return workflow

    def get_default_block_configs(self) -> list[dict]:
        """
        Get default block configs
        """
        # return default block config
        workflow_engine_manager = WorkflowEngineManager()
        return workflow_engine_manager.get_default_configs()

    def get_default_block_config(self, node_type: str, filters: Optional[dict] = None) -> Optional[dict]:
        """
        Get default config of node.
        :param node_type: node type
        :param filters: filter by node config parameters.
        :return:
        """
        node_type = NodeType.value_of(node_type)

        # return default block config
        workflow_engine_manager = WorkflowEngineManager()
        return workflow_engine_manager.get_default_config(node_type, filters)

    def run_draft_workflow_node(self, app_model: App,
                                node_id: str,
                                user_inputs: dict,
                                account: Account) -> WorkflowNodeExecution:
        """
        Run draft workflow node
        """
        # fetch draft workflow by app_model
        draft_workflow = self.get_draft_workflow(app_model=app_model)
        if not draft_workflow:
            raise ValueError('Workflow not initialized')

        # run draft workflow node
        workflow_engine_manager = WorkflowEngineManager()
        start_at = time.perf_counter()

        try:
            node_instance, node_run_result = workflow_engine_manager.single_step_run_workflow_node(
                workflow=draft_workflow,
                node_id=node_id,
                user_inputs=user_inputs,
                user_id=account.id,
            )
        except WorkflowNodeRunFailedError as e:
            workflow_node_execution = WorkflowNodeExecution(
                tenant_id=app_model.tenant_id,
                app_id=app_model.id,
                workflow_id=draft_workflow.id,
                triggered_from=WorkflowNodeExecutionTriggeredFrom.SINGLE_STEP.value,
                index=1,
                node_id=e.node_id,
                node_type=e.node_type.value,
                title=e.node_title,
                status=WorkflowNodeExecutionStatus.FAILED.value,
                error=e.error,
                elapsed_time=time.perf_counter() - start_at,
                created_by_role=CreatedByRole.ACCOUNT.value,
                created_by=account.id,
                created_at=datetime.now(timezone.utc).replace(tzinfo=None),
                finished_at=datetime.now(timezone.utc).replace(tzinfo=None)
            )
            db.session.add(workflow_node_execution)
            db.session.commit()

            return workflow_node_execution

        if node_run_result.status == WorkflowNodeExecutionStatus.SUCCEEDED:
            # create workflow node execution
            workflow_node_execution = WorkflowNodeExecution(
                tenant_id=app_model.tenant_id,
                app_id=app_model.id,
                workflow_id=draft_workflow.id,
                triggered_from=WorkflowNodeExecutionTriggeredFrom.SINGLE_STEP.value,
                index=1,
                node_id=node_id,
                node_type=node_instance.node_type.value,
                title=node_instance.node_data.title,
                inputs=json.dumps(node_run_result.inputs) if node_run_result.inputs else None,
                process_data=json.dumps(node_run_result.process_data) if node_run_result.process_data else None,
                outputs=json.dumps(jsonable_encoder(node_run_result.outputs)) if node_run_result.outputs else None,
                execution_metadata=(json.dumps(jsonable_encoder(node_run_result.metadata))
                                    if node_run_result.metadata else None),
                status=WorkflowNodeExecutionStatus.SUCCEEDED.value,
                elapsed_time=time.perf_counter() - start_at,
                created_by_role=CreatedByRole.ACCOUNT.value,
                created_by=account.id,
                created_at=datetime.now(timezone.utc).replace(tzinfo=None),
                finished_at=datetime.now(timezone.utc).replace(tzinfo=None)
            )
        else:
            # create workflow node execution
            workflow_node_execution = WorkflowNodeExecution(
                tenant_id=app_model.tenant_id,
                app_id=app_model.id,
                workflow_id=draft_workflow.id,
                triggered_from=WorkflowNodeExecutionTriggeredFrom.SINGLE_STEP.value,
                index=1,
                node_id=node_id,
                node_type=node_instance.node_type.value,
                title=node_instance.node_data.title,
                status=node_run_result.status.value,
                error=node_run_result.error,
                elapsed_time=time.perf_counter() - start_at,
                created_by_role=CreatedByRole.ACCOUNT.value,
                created_by=account.id,
                created_at=datetime.now(timezone.utc).replace(tzinfo=None),
                finished_at=datetime.now(timezone.utc).replace(tzinfo=None)
            )

        db.session.add(workflow_node_execution)
        db.session.commit()

        return workflow_node_execution

    def convert_to_workflow(self, app_model: App, account: Account, args: dict) -> App:
        """
        Basic mode of chatbot app(expert mode) to workflow
        Completion App to Workflow App

        :param app_model: App instance
        :param account: Account instance
        :param args: dict
        :return:
        """
        # chatbot convert to workflow mode
        workflow_converter = WorkflowConverter()

        if app_model.mode not in [AppMode.CHAT.value, AppMode.COMPLETION.value]:
            raise ValueError(f'Current App mode: {app_model.mode} is not supported convert to workflow.')

        # convert to workflow
        new_app = workflow_converter.convert_to_workflow(
            app_model=app_model,
            account=account,
            name=args.get('name'),
            icon=args.get('icon'),
            icon_background=args.get('icon_background'),
        )

        return new_app

    def validate_features_structure(self, app_model: App, features: dict) -> dict:
        if app_model.mode == AppMode.ADVANCED_CHAT.value:
            return AdvancedChatAppConfigManager.config_validate(
                tenant_id=app_model.tenant_id,
                config=features,
                only_structure_validate=True
            )
        elif app_model.mode == AppMode.WORKFLOW.value:
            return WorkflowAppConfigManager.config_validate(
                tenant_id=app_model.tenant_id,
                config=features,
                only_structure_validate=True
            )
        else:
            raise ValueError(f"Invalid app mode: {app_model.mode}")