add decoders and tests

boswatch/decoder/pocsag.py

@@ -0,0 +1,83 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+"""!
+    ____  ____  ______       __      __       __       _____
+   / __ )/ __ \/ ___/ |     / /___ _/ /______/ /_     |__  /
+  / __  / / / /\__ \| | /| / / __ `/ __/ ___/ __ \     /_ <
+ / /_/ / /_/ /___/ /| |/ |/ / /_/ / /_/ /__/ / / /   ___/ /
+/_____/\____//____/ |__/|__/\__,_/\__/\___/_/ /_/   /____/
+                German BOS Information Script
+                     by Bastian Schroll
+
+@file:        pocsag.py
+@date:        06.01.2018
+@author:      Bastian Schroll
+@description: Decoder class for pocsag
+"""
+
+import logging
+import re
+
+from boswatch.packet import packet
+
+logging.debug("- %s loaded", __name__)
+
+
+class Pocsag:
+    """!POCSAG decoder class
+
+    This class decodes POCSAG data.
+    First step is to validate the data and check if the format is correct.
+    In the last step a valid BOSWatch packet is created and returned"""
+
+    def __init__(self):
+        """!Create a new instance"""
+        logging.debug("POCSAG decoder started")
+
+    def decode(self, data):
+        """!Decodes POCSAG
+
+        @param data: POCSAG for decoding
+        @return BOSWatch POCSAG packet or None"""
+        bitrate = None
+        ric = None
+        subric = None
+
+        if "POCSAG512:" in data:
+            bitrate = 512
+            ric = data[20:27].replace(" ", "").zfill(7)
+            subric = str(int(data[39]) + 1)
+
+        elif "POCSAG1200:" in data:
+            bitrate = 1200
+            ric = data[21:28].replace(" ", "").zfill(7)
+            subric = str(int(data[40]) + 1)
+
+        elif "POCSAG2400:" in data:
+            bitrate = 2400
+            ric = data[21:28].replace(" ", "").zfill(7)
+            subric = str(int(data[40]) + 1)
+
+        if re.search("[0-9]{7}", ric) and re.search("[1-4]{1}", subric):
+            if "Alpha:" in data:
+                message = data.split('Alpha:   ')[1].strip()
+                message = message.replace('<NUL><NUL>', '').replace('<NUL>', '').replace('<NUL', '').replace('< NUL>', '').replace('<EOT>', '').strip()
+            else:
+                message = ""
+            subricText = subric.replace("1", "a").replace("2", "b").replace("3", "c").replace("4", "d")
+
+            logging.debug("found valid POCSAG")
+
+            bwPacket = packet.Packet()
+            bwPacket.setField("mode", "pocsag")
+            bwPacket.setField("bitrate", bitrate)
+            bwPacket.setField("ric", ric)
+            bwPacket.setField("subric", subric)
+            bwPacket.setField("subricText", subricText)
+            bwPacket.setField("message", message)
+
+            logging.debug(bwPacket)
+            return bwPacket
+
+        logging.warning("no valid data")
+        return None