openwebrx-clone/owrx/meta.py

from owrx.config import PropertyManager
from urllib import request
import json
from datetime import datetime, timedelta
import logging
import threading

logger = logging.getLogger(__name__)

class DmrCache(object):
    sharedInstance = None
    @staticmethod
    def getSharedInstance():
        if DmrCache.sharedInstance is None:
            DmrCache.sharedInstance = DmrCache()
        return DmrCache.sharedInstance
    def __init__(self):
        self.cache = {}
        self.cacheTimeout = timedelta(seconds = 86400)
    def isValid(self, key):
        if not key in self.cache: return False
        entry = self.cache[key]
        return entry["timestamp"] + self.cacheTimeout > datetime.now()
    def put(self, key, value):
        self.cache[key] = {
            "timestamp": datetime.now(),
            "data": value
        }
    def get(self, key):
        if not self.isValid(key): return None
        return self.cache[key]["data"]


class DmrMetaEnricher(object):
    def __init__(self):
        self.threads = {}
    def downloadRadioIdData(self, id):
        cache = DmrCache.getSharedInstance()
        try:
            logger.debug("requesting DMR metadata for id=%s", id)
            res = request.urlopen("https://www.radioid.net/api/dmr/user/?id={0}".format(id), timeout=30).read()
            data = json.loads(res.decode("utf-8"))
            cache.put(id, data)
        except json.JSONDecodeError:
            cache.put(id, None)
        del self.threads[id]
    def enrich(self, meta):
        if not PropertyManager.getSharedInstance()["digital_voice_dmr_id_lookup"]: return None
        if not "source" in meta: return None
        id = meta["source"]
        cache = DmrCache.getSharedInstance()
        if not cache.isValid(id):
            if not id in self.threads:
                self.threads[id] = threading.Thread(target=self.downloadRadioIdData, args=[id])
                self.threads[id].start()
            return None
        data = cache.get(id)
        if "count" in data and data["count"] > 0 and "results" in data:
            return data["results"][0]
        return None


class MetaParser(object):
    enrichers = {
        "DMR": DmrMetaEnricher()
    }
    def __init__(self, handler):
        self.handler = handler
    def parse(self, meta):
        fields = meta.split(";")
        meta = {v[0] : "".join(v[1:]) for v in map(lambda x: x.split(":"), fields)}

        if "protocol" in meta:
            protocol = meta["protocol"]
            if protocol in MetaParser.enrichers:
                additional_data = MetaParser.enrichers[protocol].enrich(meta)
                if additional_data is not None: meta["additional"] = additional_data
        self.handler.write_metadata(meta)