feat: enhance Redis action handling; add dynamic context for actions and support for expiration time

pympta.md

@@ -64,16 +64,26 @@ This file defines the entire pipeline logic. The root object contains a `pipelin
 
 ### Action Object Structure
 
-Actions allow the pipeline to interact with Redis.
+Actions allow the pipeline to interact with Redis. They are executed sequentially for a given detection.
+
+#### Action Context & Dynamic Keys
+
+All actions have access to a dynamic context for formatting keys and messages. The context is created for each detection event and includes:
+
+- All key-value pairs from the detection result (e.g., `class`, `confidence`, `id`).
+- `{timestamp_ms}`: The current Unix timestamp in milliseconds.
+- `{uuid}`: A unique identifier (UUID4) for the detection event.
+- `{image_key}`: If a `redis_save_image` action has already been executed for this event, this placeholder will be replaced with the key where the image was stored.
 
 #### `redis_save_image`
 
 Saves the current image frame (or cropped sub-image) to a Redis key.
 
-| Key   | Type   | Required | Description                                                                                             |
-| ----- | ------ | -------- | ------------------------------------------------------------------------------------------------------- |
-| `type`| String | Yes      | Must be `"redis_save_image"`.                                                                           |
-| `key` | String | Yes      | The Redis key to save the image to. Can contain placeholders like `{class}` or `{id}` to be formatted with detection results. |
+| Key              | Type   | Required | Description                                                                                             |
+| ---------------- | ------ | -------- | ------------------------------------------------------------------------------------------------------- |
+| `type`           | String | Yes      | Must be `"redis_save_image"`.                                                                           |
+| `key`            | String | Yes      | The Redis key to save the image to. Can contain any of the dynamic placeholders.                        |
+| `expire_seconds` | Number | No       | If provided, sets an expiration time (in seconds) for the Redis key.                                    |
 
 #### `redis_publish`
 
@@ -83,43 +93,37 @@ Publishes a message to a Redis channel.
 | --------- | ------ | -------- | ------------------------------------------------------------------------------------------------------- |
 | `type`    | String | Yes      | Must be `"redis_publish"`.                                                                              |
 | `channel` | String | Yes      | The Redis channel to publish the message to.                                                            |
-| `message` | String | Yes      | The message to publish. Can contain placeholders like `{class}` or `{id}` to be formatted with detection results. |
+| `message` | String | Yes      | The message to publish. Can contain any of the dynamic placeholders, including `{image_key}`.           |
 
 ### Example `pipeline.json` with Redis
 
+This example demonstrates a pipeline that detects vehicles, saves a uniquely named image of each detection that expires in one hour, and then publishes a notification with the image key.
+
 ```json
 {
   "redis": {
-    "host": "localhost",
+    "host": "redis.local",
     "port": 6379,
-    "password": "your-password"
+    "password": "your-super-secret-password"
   },
   "pipeline": {
     "modelId": "vehicle-detector",
     "modelFile": "vehicle_model.pt",
-    "minConfidence": 0.5,
+    "minConfidence": 0.6,
     "triggerClasses": ["car", "truck"],
     "actions": [
       {
         "type": "redis_save_image",
-        "key": "detection:image:{id}"
+        "key": "detections:{class}:{timestamp_ms}:{uuid}",
+        "expire_seconds": 3600
       },
       {
         "type": "redis_publish",
-        "channel": "detections",
-        "message": "Detected a {class} with ID {id}"
+        "channel": "vehicle_events",
+        "message": "{\"event\":\"new_detection\",\"class\":\"{class}\",\"confidence\":{confidence},\"image_key\":\"{image_key}\"}"
       }
     ],
-    "branches": [
-      {
-        "modelId": "lpr-us",
-        "modelFile": "lpr_model.pt",
-        "minConfidence": 0.7,
-        "triggerClasses": ["car"],
-        "crop": true,
-        "branches": []
-      }
-    ]
+    "branches": []
   }
 }
 ```

siwatsystem/pympta.py

@@ -8,6 +8,8 @@ import zipfile
 import shutil
 import traceback
 import redis
+import time
+import uuid
 from ultralytics import YOLO
 from urllib.parse import urlparse
 
@@ -195,16 +197,30 @@ def execute_actions(node, frame, detection_result):
     if not node["redis_client"] or not node["actions"]:
         return
 
+    # Create a dynamic context for this detection event
+    action_context = {
+        **detection_result,
+        "timestamp_ms": int(time.time() * 1000),
+        "uuid": str(uuid.uuid4()),
+    }
+
     for action in node["actions"]:
         try:
             if action["type"] == "redis_save_image":
-                key = action["key"].format(**detection_result)
+                key = action["key"].format(**action_context)
                 _, buffer = cv2.imencode('.jpg', frame)
-                node["redis_client"].set(key, buffer.tobytes())
-                logger.info(f"Saved image to Redis with key: {key}")
+                expire_seconds = action.get("expire_seconds")
+                if expire_seconds:
+                    node["redis_client"].setex(key, expire_seconds, buffer.tobytes())
+                    logger.info(f"Saved image to Redis with key: {key} (expires in {expire_seconds}s)")
+                else:
+                    node["redis_client"].set(key, buffer.tobytes())
+                    logger.info(f"Saved image to Redis with key: {key}")
+                # Add the generated key to the context for subsequent actions
+                action_context["image_key"] = key
             elif action["type"] == "redis_publish":
                 channel = action["channel"]
-                message = action["message"].format(**detection_result)
+                message = action["message"].format(**action_context)
                 node["redis_client"].publish(channel, message)
                 logger.info(f"Published message to Redis channel '{channel}': {message}")
         except Exception as e: