From bb148906e7b94a551335e93f9ac4c6ff28204cf6 Mon Sep 17 00:00:00 2001
From: yihong1120 <qazsx748596@gmail.com>
Date: Mon, 20 May 2024 02:07:03 +0800
Subject: [PATCH] Utilise web socket to conduct image frames to frontend

---
 examples/Stream-Web/app.py                | 154 ++++++++++++++--------
 examples/Stream-Web/static/css/styles.css |  19 +++
 2 files changed, 115 insertions(+), 58 deletions(-)

diff --git a/examples/Stream-Web/app.py b/examples/Stream-Web/app.py
index 724ede5..70760d5 100644
--- a/examples/Stream-Web/app.py
+++ b/examples/Stream-Web/app.py
@@ -1,105 +1,147 @@
 import base64
-from tkinter import image_names
-from flask import Flask, redirect, render_template, send_from_directory, make_response, Response, request, jsonify, url_for
-import subprocess
-import threading
-import os
-import signal
-from threading import Timer
+from flask import Flask, abort, render_template, make_response, Response
 from flask_limiter import Limiter
 from flask_limiter.util import get_remote_address
-from pathlib import Path
-import json
-import uuid
-import time
 import redis
-import pickle
-import cv2
-import numpy as np
+from flask_socketio import SocketIO, emit
+from flask_cors import CORS
+from typing import List, Tuple
 
 # Connect to Redis
 r = redis.Redis(host='localhost', port=6379, db=0)
 
 app = Flask(__name__)
+CORS(app)  # Allow cross-origin requests from any domain
+socketio = SocketIO(app, cors_allowed_origins="*")  # Allow all origins for WebSocket connections
 limiter = Limiter(key_func=get_remote_address)
 
-DETECTED_FRAMES_DIR = Path.cwd() / 'detected_frames'
 CACHE_DURATION = 60  # Cache duration in seconds
-cache = {}
+
+def get_labels() -> List[str]:
+    """
+    Retrieve and decode all unique labels from Redis keys.
+
+    Returns:
+        list: Sorted list of unique labels.
+    """
+    cursor, keys = r.scan()
+    decoded_keys = [key.decode('utf-8') for key in keys]
+    labels = {key.split('_')[0] for key in decoded_keys if key.count('_') == 1 and not key.startswith('_') and not key.endswith('_')}
+    return sorted(labels)
+
+def get_image_data(label: str) -> List[Tuple[str, str]]:
+    """
+    Retrieve and process image data for a specific label.
+
+    Args:
+        label (str): The label/category of the images.
+
+    Returns:
+        list: List of tuples containing base64 encoded images and their names.
+    """
+    cursor, keys = r.scan(match=f'{label}_*')
+    image_data = [(base64.b64encode(r.get(key)).decode('utf-8'), key.decode('utf-8').split('_')[1]) for key in keys]
+    return sorted(image_data, key=lambda x: x[1])
 
 @app.route('/')
-@limiter.limit("60 per minute")  # Apply rate limiting to this endpoint
+@limiter.limit("60 per minute")
 def index() -> str:
     """
-    Serves the index page with a dynamically generated list of labels from subdirectories.
+    Serve the index page with a dynamically generated list of labels from Redis.
 
     Returns:
         str: The rendered 'index.html' page.
     """
-    labels = [d.name for d in DETECTED_FRAMES_DIR.iterdir() if d.is_dir()]
-    labels.sort()
+    labels = get_labels()
     return render_template('index.html', labels=labels)
 
-@app.route('/label/<label>')
-@limiter.limit("60 per minute")  # Apply rate limiting to this endpoint
+@app.route('/label/<label>', methods=['GET'])
+@limiter.limit("60 per minute")
 def label_page(label: str) -> str:
     """
-    Serves a page for each label, displaying images under that label.
+    Serve a page for each label, displaying images under that label.
 
     Args:
-        label: The label/category of the images.
+        label (str): The label/category of the images.
 
     Returns:
         str: The rendered 'label.html' page for the specific label.
     """
-    # Get all keys from Redis
-    keys = r.keys()
-    # Filter keys for this label
-    label_keys = [key for key in keys if key.decode('utf-8').startswith(label)]
-    images = []
-
-    for key in label_keys:
-        # Get the frame from Redis
-        frame_bytes = pickle.loads(r.get(key))
-        # Convert the byte array back to a frame
-        nparr = np.fromstring(frame_bytes, np.uint8)
-        frame = cv2.imdecode(nparr, cv2.IMREAD_COLOR)
-        # Convert the frame to base64
-        _, buffer = cv2.imencode('.png', frame)
-        png_as_text = base64.b64encode(buffer).decode('utf-8')
-        images.append(png_as_text)
-
-    return render_template('label.html', label=label, images=images)
+    image_data = get_image_data(label)
+    return render_template('label.html', label=label, image_data=image_data)
+
+@socketio.on('connect')
+def handle_connect() -> None:
+    """
+    Handle client connection to the WebSocket.
+    """
+    emit('message', {'data': 'Connected'})
+    socketio.start_background_task(update_images)
+
+@socketio.on('disconnect')
+def handle_disconnect() -> None:
+    """
+    Handle client disconnection from the WebSocket.
+    """
+    print('Client disconnected')
+
+@socketio.on('error')
+def handle_error(e: Exception) -> None:
+    """
+    Handle errors in WebSocket communication.
+
+    Args:
+        e (Exception): The exception that occurred.
+    """
+    print(f'Error: {str(e)}')
+
+def update_images() -> None:
+    """
+    Update images every 10 seconds by scanning Redis and emitting updates to clients.
+    """
+    while True:
+        socketio.sleep(10)  # Execute every 20 seconds
+        labels = get_labels()
+        for label in labels:
+            image_data = get_image_data(label)
+            socketio.emit('update', {'label': label, 'images': [img for img, _ in image_data], 'image_names': [name for _, name in image_data]})
 
 @app.route('/image/<label>/<filename>.png')
-@limiter.limit("60 per minute")  # Apply rate limiting to this endpoint
+@limiter.limit("60 per minute")
 def image(label: str, filename: str) -> Response:
     """
-    Serves an image file from a label subdirectory.
+    Serve an image file from Redis.
 
     Args:
-        label: The label/category of the image.
-        filename: The filename of the image.
+        label (str): The label/category of the image.
+        filename (str): The filename of the image.
 
     Returns:
         Response: The image file as a response.
     """
-    image_path = DETECTED_FRAMES_DIR / label / (filename + '.png')
-    response = make_response(send_from_directory(image_path.parent, image_path.name))
+    redis_key = f"{label}_{filename}"
+    img_encoded = r.get(redis_key)
+
+    if img_encoded is None:
+        abort(404, description="Resource not found")
+
+    response = make_response(img_encoded)
+    response.headers.set('Content-Type', 'image/png')
     response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
     response.headers['Pragma'] = 'no-cache'
     response.headers['Expires'] = '0'
+
     return response
 
 @app.route('/camera/<label>/<camera_id>')
-@limiter.limit("60 per minute")  # Apply rate limiting to this endpoint
+@limiter.limit("60 per minute")
 def camera_page(label: str, camera_id: str) -> str:
     """
-    Serves a page for viewing the camera stream.
+    Serve a page for viewing the camera stream.
 
     Args:
-        label: The label/category of the camera.
-        camera_id: The specific ID of the camera to view.
+        label (str): The label/category of the camera.
+        camera_id (str): The specific ID of the camera to view.
 
     Returns:
         str: The rendered 'camera.html' page for the specific camera.
@@ -107,9 +149,5 @@ def camera_page(label: str, camera_id: str) -> str:
     return render_template('camera.html', label=label, camera_id=camera_id)
 
 if __name__ == '__main__':
-    # Run the Flask application on localhost at port 8000.
-    app.run(thread=True,host='127.0.0.1', port=8000, debug=False)
-
-""" example usage
-gunicorn -w 4 -b 127.0.0.1:8000 "examples.Stream-Web.app:app"
-"""
\ No newline at end of file
+    socketio.start_background_task(target=update_images)
+    socketio.run(app, host='127.0.0.1', port=8000, debug=False)
diff --git a/examples/Stream-Web/static/css/styles.css b/examples/Stream-Web/static/css/styles.css
index cdf300c..5198d01 100644
--- a/examples/Stream-Web/static/css/styles.css
+++ b/examples/Stream-Web/static/css/styles.css
@@ -35,6 +35,25 @@ h1 {
     box-shadow: 0 2px 5px rgba(0,0,0,0.1);
 }
 
+/* Forced Colors Mode adjustments */
+@media (forced-colors: active) {
+    body {
+        forced-color-adjust: auto;
+        background-color: Canvas;
+        color: CanvasText;
+    }
+
+    .camera {
+        background: Canvas;
+        color: CanvasText;
+        box-shadow: none; /* Simplify styles in high contrast mode */
+    }
+
+    .camera img {
+        border-radius: 0; /* Disable rounded corners in high contrast mode */
+    }
+}
+
 /* Responsive design adjustments */
 @media (max-width: 600px) {
     .camera-grid {