Added some code to automatically refresh the feed file if it changed

.ipynb_checkpoints/Playground-checkpoint.ipynb

@@ -0,0 +1,48 @@
+{
+ "cells": [
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "id": "1f552469",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import gtfs_kit as gk\n",
+    "import pandas as pd\n",
+    "import datetime\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "292cc196",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "feed=gk.read_feed('google_transit_combined.zip', dist_units='km')\n",
+    "feed"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.10.7"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

.vscode/launch.json

@@ -0,0 +1,16 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Python: GTFS Client",
+            "type": "python",
+            "request": "launch",
+            "program": "gtfs_client.py",
+            "console": "integratedTerminal",
+            "justMyCode": true
+        }
+    ]
+}

gtfs_client.py

@@ -1,6 +1,9 @@
+
+import refresh_feed
 from arrival_times import ArrivalTime
 import datetime
 import gtfs_kit as gk
+import os
 import pandas as pd
 import queue
 import time
@@ -8,8 +11,19 @@ import threading
 import traceback
 
 class GTFSClient():
-    def __init__(self, feed_name: str, stop_names: list[str], update_queue: queue.Queue, update_interval_seconds: int = 60):
+    def __init__(self, feed_url: str, stop_names: list[str], update_queue: queue.Queue, update_interval_seconds: int = 60):
         self.stop_names = stop_names
+        feed_name = feed_url.split('/')[-1]
+
+        # Make sure that the feed file is up to date
+        last_mtime = os.stat(feed_name).st_mtime
+        refreshed, new_mtime = refresh_feed.update_local_file_from_url_v1(last_mtime, feed_name, feed_url)
+        if refreshed:
+            print("The feed file was refreshed.")
+        else:
+            print("The feed file was up to date")
+
+        # Load the feed
         self.feed = gk.read_feed(feed_name, dist_units='km')
         self.stop_ids = self.__wanted_stop_ids()
 
@@ -110,6 +124,11 @@ class GTFSClient():
         return joined_data
 
 
+    def start(self) -> None:
+        """ Start the refresh thread """
+        self._refresh_thread.start()
+        self.refresh()
+
 
     def refresh(self):
         """
@@ -149,7 +168,7 @@ def every(delay, task) -> None:
         # skip tasks if we are behind schedule:
         next_time += (time.time() - next_time) // delay * delay + delay
 
-
-c = GTFSClient('google_transit_combined.zip', ['College Drive, stop 2410', 'Priory Walk, stop 1114'], None, None)
-
-print(c.refresh())
+if __name__ == "__main__":
+    c = GTFSClient('https://www.transportforireland.ie/transitData/google_transit_combined.zip', 
+                   ['College Drive, stop 2410', 'Priory Walk, stop 1114'], None, None)
+    print(c.refresh())

main.py

@@ -8,6 +8,7 @@ from time import sleep
 from dublinbus_soap_client import DublinBusSoapClient
 import queue
 from arrival_times import ArrivalTime
+from gtfs_client import GTFSClient
 
 # Constants
 # The font is JD LCD Rounded by Jecko Development 
@@ -22,8 +23,8 @@ COLOR_BACKGROUND = pygame.Color(0, 0, 0)
 UPDATE_INTERVAL_SECONDS = 30
 TEXT_SIZE = 160  # Size of the font in pixels
 STOPS = [
-    2410, # College Drive
-    1114  # Priory Walk
+    'College Drive, stop 2410', 
+    'Priory Walk, stop 1114',
 ]
 
 # Define how long it takes to walk to a particular stop
@@ -42,8 +43,8 @@ INTER_LINE_SPACE = -20 # 1920x720 -> 0
 window : pygame.Surface = None
 font: pygame.font.Font = None
 update_queue = queue.Queue(maxsize=10)
-dublinbus_client = DublinBusSoapClient(stops=STOPS, update_queue=update_queue, update_interval_seconds=UPDATE_INTERVAL_SECONDS)
-
+#dublinbus_client = DublinBusSoapClient(stops=STOPS, update_queue=update_queue, update_interval_seconds=UPDATE_INTERVAL_SECONDS)
+dublinbus_client = GTFSClient(feed_name='google_transit_combined.zip', stop_names=STOPS, update_queue=update_queue, update_interval_seconds=UPDATE_INTERVAL_SECONDS)
 
 def get_line_offset(line: int) -> int:
     """ Calculate the Y offset within the display for a given text line """

refresh_feed.py

@@ -0,0 +1,104 @@
+# Refresh the feed file from the original source
+# Only download the file if the source is newer than the local copy
+# This code was adapted from https://forums.raspberrypi.com/viewtopic.php?t=152226#p998268
+
+import email.utils
+import os
+import sys
+import time
+import requests
+
+# First we construct a handful of functions - testing happens down at the end
+def httpdate_to_ts(dt):
+    time_tuple = email.utils.parsedate_tz(dt)
+    return 0 if time_tuple is None else email.utils.mktime_tz(time_tuple)
+
+
+def ts_to_httpdate(ts):
+    return email.utils.formatdate(timeval=ts, localtime=False, usegmt=True)
+
+
+def write_file_with_time(filename, content, timestamp):
+    # put the content into the file
+    with open(filename, 'wb') as fp:
+        fp.write(content)
+
+    # Then set the file's timestamps as requested
+    os.utime(filename, times=(time.time(), timestamp))
+
+
+# v1: download remote file if HTTP's Last-Modified header indicates that
+#     the file has been updated. This requires the remote server to support
+#     sending the Last-Modified header.
+#
+def update_local_file_from_url_v1(last_mtime, local_file, url):
+
+    # Check the status of the remote file without downloading it
+    r1 = requests.head(url)
+    if r1.status_code != requests.codes.ok:
+        # http request failed
+        print('HEY! get for {} returned {}'.format(url, r1.status_code),
+              file=sys.stderr)
+        return False, last_mtime
+
+    # Get the modification time for the file, if possible
+    if 'Last-Modified' in r1.headers:
+        mtime = httpdate_to_ts(r1.headers['Last-Modified'])
+    else:
+        print('HEY! no Last-Modified header for {}'.format(url),
+              file=sys.stderr)
+        return False, last_mtime
+
+    # If file is newer than last one we saw, get it
+    updated = False
+    if mtime > int(last_mtime):
+        updated = True
+        r2 = requests.get(url)  # download the new file content
+        if r2.status_code != requests.codes.ok:
+            # http request failed
+            print('HEY! get for {} returned {}'.format(url, r2.status_code),
+                  file=sys.stderr)
+            return False, last_mtime
+
+        # write new content to local file
+        write_file_with_time(local_file, r2.content, mtime)
+
+    return updated, mtime
+
+
+# v2: download remote file conditionally, with HTTP's If-Modified-Since header.
+#     This requires the remote server to support both sending the Last-Modified
+#     header and receiving the If-Modified-Since header.
+#
+def update_local_file_from_url_v2(last_mtime, local_file, url):
+
+    # Get the remote file, but only if it has changed
+    r = requests.get(url, headers={
+                              'If-Modified-Since': ts_to_httpdate(last_mtime)
+                          })
+
+    updated, mtime = False, last_mtime
+
+    if r.status_code == requests.codes.ok:
+        # File is updated and we just downloaded the content
+        updated = True
+
+        # write new content to local file
+        write_file_with_time(local_file, r.content, mtime)
+
+        # Update our notion of the file's last modification time
+        if 'Last-Modified' in r.headers:
+            mtime = httpdate_to_ts(r.headers['Last-Modified'])
+        else:
+            print('HEY! no Last-Modified header for {}'.format(url),
+                  file=sys.stderr)
+
+    elif r.status_code == requests.codes.not_modified:
+        # Successful call, but no updates to file
+        print('As of {}, server says {} is the same'.format(time.ctime(), url))
+    else:
+        # http request failed
+        print('HEY! get for {} returned {}'.format(url, r.status_code),
+              file=sys.stderr)
+
+    return updated, mtime