feat(trigger): add workflows_in_use field to TriggerProviderSubscriptionApiEntity

- Introduced a new field `workflows_in_use` to the TriggerProviderSubscriptionApiEntity to track the number of workflows utilizing each subscription.
- Enhanced the TriggerProviderService to populate this field by querying the WorkflowPluginTrigger model for usage counts associated with each subscription.

This addition improves the visibility of subscription usage within the trigger provider context.

api/core/trigger/entities/api_entities.py

@@ -23,6 +23,7 @@ class TriggerProviderSubscriptionApiEntity(BaseModel):
     endpoint: str = Field(description="The endpoint of the subscription")
     parameters: dict = Field(description="The parameters of the subscription")
     properties: dict = Field(description="The properties of the subscription")
+    workflows_in_use: int = Field(description="The number of workflows using this subscription")
 
 
 class TriggerApiEntity(BaseModel):

api/services/trigger/trigger_provider_service.py

@@ -4,7 +4,7 @@ import uuid
 from collections.abc import Mapping
 from typing import Any, Optional
 
-from sqlalchemy import desc
+from sqlalchemy import desc, func
 from sqlalchemy.orm import Session
 
 from configs import dify_config
@@ -29,6 +29,7 @@ from core.trigger.utils.encryption import (
 from extensions.ext_database import db
 from extensions.ext_redis import redis_client
 from models.trigger import TriggerOAuthSystemClient, TriggerOAuthTenantClient, TriggerSubscription
+from models.workflow import WorkflowPluginTrigger
 from services.plugin.plugin_service import PluginService
 
 logger = logging.getLogger(__name__)
@@ -53,7 +54,9 @@ class TriggerProviderService:
     ) -> list[TriggerProviderSubscriptionApiEntity]:
         """List all trigger subscriptions for the current tenant"""
         subscriptions: list[TriggerProviderSubscriptionApiEntity] = []
+        workflows_in_use_map: dict[str, int] = {}
         with Session(db.engine, autoflush=False) as session:
+            # Get all subscriptions
             subscriptions_db = (
                 session.query(TriggerSubscription)
                 .filter_by(tenant_id=tenant_id, provider_id=str(provider_id))
@@ -62,6 +65,24 @@ class TriggerProviderService:
             )
             subscriptions = [subscription.to_api_entity() for subscription in subscriptions_db]
 
+            # Get distinct app count for each subscription
+            if subscriptions:
+                usage_counts = (
+                    session.query(
+                        WorkflowPluginTrigger.subscription_id,
+                        func.count(func.distinct(WorkflowPluginTrigger.app_id)).label("app_count"),
+                    )
+                    .filter(
+                        WorkflowPluginTrigger.tenant_id == tenant_id,
+                        WorkflowPluginTrigger.subscription_id.in_([s.id for s in subscriptions]),
+                    )
+                    .group_by(WorkflowPluginTrigger.subscription_id)
+                    .all()
+                )
+                # Convert query result to dictionary: subscription_id -> distinct app count
+                workflows_in_use_map = {str(row.subscription_id): int(row.app_count) for row in usage_counts}
+
+        # Process subscriptions and mask credentials
         provider_controller = TriggerManager.get_trigger_provider(tenant_id, provider_id)
         for subscription in subscriptions:
             encrypter, _ = create_trigger_provider_encrypter_for_subscription(
@@ -70,6 +91,10 @@ class TriggerProviderService:
                 subscription=subscription,
             )
             subscription.credentials = encrypter.mask_credentials(subscription.credentials)
+            # Set workflows_in_use count, default to 0 if not found
+            count = workflows_in_use_map.get(subscription.id)
+            subscription.workflows_in_use = count if count is not None else 0
+
         return subscriptions
 
     @classmethod