<?php
$homeserver = "glasgow.social";
$access_token = "access_token_goes_here";

// this is so you can start and stop the program, and it'll continue where it left off
$tracking_file "/tmp/listen_matrix.json";

while(true) {
$since = file_get_contents($tracking_file);
$messages = get_new_events($since);
if(!empty($messages['rooms']['join'] and is_array($messages['rooms']['join']))) {
   foreach($messages['rooms']['join'] as $room_id=>$data) {
      foreach($data['timeline']['events'] as $event_id=>$event) {
         if($event['type'] == "m.room.message") {
            $sender = $event['sender'];
            $content = "not text";
            if($event['content']['msgtype'] == "m.text")
               $content = $event['content']['body'];
            echo "$sender $room_id $content\n";
         }
      }
   }
}
$new_tracking_data = $messages['next_batch'];
file_put_contents($tracking_file, $new_tracking_data);
}

function get_new_events($since) {
   global $homeserver,$access_token;
   // timeout means the server will wait and only respond after 30 seconds, 
   // however if a message is returned before that time, it will return immediately
   $url = "https://$homeserver/_matrix/client/r0/sync?access_token=$access_token&timeout=30000";
   if(!empty($since))
      $url .= "&since=$since";
   $data = json_decode(file_get_contents($url), true);
   return $data;
}


?>