Added background ALPR to dash-cam mode

CHANGELOG.md

@@ -495,3 +495,4 @@ This update focuses on unifying Predator's different modes to allow multipurpose
 - Remote alert database sources can now be cached.
     - This allows Predator to continue using entries from a remote alert database even when the source goes offline.
 - Migrated most of the ALPR processing to a dedicated file for sake of organization.
+- The "detected plate" notification sound now plays regardless of the console output level.

alpr.py

@@ -17,6 +17,7 @@
 import json # Required to process JSON data
 
 
+
 predator_root_directory = str(os.path.dirname(os.path.realpath(__file__))) # This variable determines the folder path of the root Predator directory. This should usually automatically recognize itself, but if it doesn't, you can change it manually.
 
 
@@ -31,6 +32,16 @@
     exit()
 
 
+try:
+    if (config["developer"]["offline"] == False): # Only import networking libraries if offline mode is turned off.
+        if (config["general"]["status_lighting"]["enabled"] == True or config["realtime"]["push_notifications"]["enabled"] == True or len(config["general"]["alerts"]["databases"]) > 0):
+            import requests # Required to make network requests
+            import validators # Required to validate URLs
+except:
+    print("Failed to determine if network features are enabled in the configuration.")
+if (len(config["general"]["alerts"]["databases"]) > 0):
+    import hashlib
+
 
 import utils
 style = utils.style # Load style information from the utils script.
@@ -110,6 +121,28 @@ def alpr_get_queued_plates(): # This function is used to fetch the latest queue
 
 
 
+# This function validates a license plate given a template.
+def validate_plate(plate, template):
+    plate_valid = True # By default, the plate is valid, until we find a character that doesn't align.
+
+    if (len(template) == len(plate)): # Make sure the template and plate are the same length. If so, continue with validation. Otherwise, automatically invalidate the plate, and skip the rest of the validation process.
+        for x in range(len(template)):
+            if (template[x].isalpha() == plate[x].isalpha() or template[x].isnumeric() == plate[x].isnumeric()): # If this character is alphabetical in both the template and plate, or if this character is numeric in both the template and plate, then this character is valid.
+                # This character is valid, so don't change anything.
+                pass
+            else:
+                # This character doesn't match between the template and plate, so mark the plate as invalid.
+                plate_valid = False
+                break # Exit the loop now, since we already know the plate is invalid.
+    else:
+        plate_valid = False
+
+    return plate_valid # Return the results of the plate validation
+
+
+
+
+
 # This function loads the license plate log, and initializes the file if necessary.
 def load_alpr_log():
     global config
@@ -150,3 +183,88 @@ def run_alpr(image_filepath):
         reading_output = {}
 
     return reading_output
+
+
+
+
+
+# This function is used to display a list of provided license plate alerts.
+def display_alerts(active_alerts):
+    for alert in active_alerts: # Iterate through each active alert.
+        # Display an alert that is starkly different from the rest of the console output.
+        print(style.yellow + style.bold)
+        print("===================")
+        print("ALERT HIT - " + str(alert))
+        if ("rule" in active_alerts[alert]): # Check to see if a rule exists for this alert plate. This should always be the case, but it's worth checking for sake of stability.
+            print("Rule: " + str(active_alerts[alert]["rule"])) # Display the rule that triggered this alert.
+        if ("name" in active_alerts[alert]): # Check to see if a name exists for this alert plate.
+            print("Name: " + str(active_alerts[alert]["name"])) # Display this alert plate's name.
+        if ("description" in active_alerts[alert]): # Check to see if a name exists for this alert plate.
+            print("Description: " + str(active_alerts[alert]["description"])) # Display this alert plate's description.
+        print("===================")
+        print(style.end + style.end)
+
+
+
+
+# The following functions are responsible for loading alert database.
+def load_alert_database_remote(source, cache_directory):
+    debug_message("Loading remote database source.")
+    if (config["realtime"]["saving"]["remote_alert_sources"] == True):
+        source_hash = hashlib.md5(source.encode()).hexdigest()
+    if (config["developer"]["offline"] == False): # Check to see if offline mode is disabled.
+        try:
+            raw_download_data = requests.get(source, timeout=6).text # Save the raw text data from the URL to a variable.
+        except:
+            raw_download_data = "{}"
+            display_message("The license plate alert database from " + source + " could not be loaded.", 2)
+            if (config["realtime"]["saving"]["remote_alert_sources"] == True):
+                if (os.path.exists(cache_directory + "/" + source_hash + ".json")): # Check to see if the cached file exists.
+                    debug_message("Attempting to load locally cached data for this remote source.")
+                    return load_alert_database_local(cache_directory + "/" + source_hash + ".json") # Load the locally cached file.
+        processed_download_data = str(raw_download_data) # Convert the downloaded data to a string.
+        try:
+            alert_database = json.loads(processed_download_data) # Load the alert database as JSON data.
+            if (config["realtime"]["saving"]["remote_alert_sources"] == True):
+                if (os.path.isdir(cache_directory) == False):
+                    os.system("mkdir -p '" + str(cache_directory) + "'")
+                save_to_file(cache_directory + "/" + source_hash + ".json", json.dumps(alert_database))
+        except:
+            alert_database = {}
+            display_message("The license plate alert database returned by the remote source " + source + " doesn't appear to be compatible JSON data. This source has not been loaded.", 2)
+    else: # Predator is in offline mode, but a remote alert database source was specified.
+        alert_database = {} # Set the alert database to an empty dictionary.
+        display_message("A remote alert database source " + source + " was specified, but Predator is in offline mode. This source has not been loaded.", 2)
+    return alert_database
+
+def load_alert_database_local(source):
+    debug_message("Loading local database source.")
+    if (os.path.exists(source)): # Check to see if the database specified by the user actually exists.
+        f = open(source, "r") # Open the user-specified database file.
+        file_contents = f.read() # Read the file.
+        if (file_contents[0] == "{"): # Check to see if the first character in the file indicates that this alert database is a JSON database.
+            alert_database = json.loads(file_contents) # Load the alert database as JSON data.
+        else:
+            alert_database = {}
+            display_message("The alert database specified at " + source + " does appear to contain compatible JSON data. This source has not been loaded.", 3)
+        f.close() # Close the file.
+    else: # If the alert database specified by the user does not exist, alert the user of the error.
+        alert_database = {}
+        display_message("The alert database specified at " + source + " does not exist. This source has not been loaded.", 3)
+
+    return alert_database
+
+def load_alert_database(sources, project_directory): # This function compiles the provided list of sources into a single complete alert dictionary.
+    cache_directory = project_directory + "/" + config["realtime"]["saving"]["remote_alert_sources"]["directory"]
+    debug_message("Loading license plate alert list")
+    complete_alert_database = {} # Set the complete alert database to a placeholder dictionary.
+    for source in sources: # Iterate through each source in the list of sources.
+        if (validators.url(source)): # Check to see if the user supplied a URL as their alert database.
+            alert_database = load_alert_database_remote(source, cache_directory)
+        else: # The input the user supplied doesn't appear to be a URL, so assume it is a file.
+            alert_database = load_alert_database_local(project_directory + "/" + source)
+
+        for rule in alert_database: # Iterate over each rule in this database.
+            complete_alert_database[rule] = alert_database[rule] # Add this rule to the complete alert database.
+
+    return complete_alert_database