"""
Subscribe to mqtt topics; generate RDF statements.
"""
import json
import sys
from docopt import docopt
from rdflib import Namespace, URIRef, Literal, Graph, RDF, XSD
from rdflib.parser import StringInputSource
from rdflib.term import Node
from twisted.internet import reactor
import cyclone.web
import rx, rx.operators, rx.scheduler.eventloop
from greplin import scales
from greplin.scales.cyclonehandler import StatsHandler

from export_to_influxdb import InfluxExporter
from mqtt_client import MqttClient

from patchablegraph import PatchableGraph, CycloneGraphHandler, CycloneGraphEventsHandler
from rdfdb.patch import Patch
from rdfdb.rdflibpatch import graphFromQuads
from standardservice.logsetup import log, verboseLogging
from standardservice.scalessetup import gatherProcessStats

ROOM = Namespace('http://projects.bigasterisk.com/room/')

gatherProcessStats()

def parseDurationLiteral(lit: Literal) -> float:
    if lit.endswith('s'):
        return float(lit.split('s')[0])
    raise NotImplementedError(f'duration literal: {lit}')


class MqttStatementSource:
    def __init__(self, uri, config, masterGraph, mqtt, influx):
        self.uri = uri
        self.config = config
        self.masterGraph = masterGraph
        self.mqtt = mqtt
        self.influx = influx

        self.mqttTopic = self.topicFromConfig(self.config)

        statPath = '/subscribed_topic/' + self.mqttTopic.decode('ascii').replace('/', '|')
        scales.init(self, statPath)
        self._mqttStats = scales.collection(
            statPath + '/incoming', scales.IntStat('count'),
            scales.RecentFpsStat('fps'))


        rawBytes = self.subscribeMqtt()
        rawBytes = rx.operators.do_action(self.countIncomingMessage)(rawBytes)
        parsed = self.getParser()(rawBytes)

        g = self.config
        for conv in g.items(g.value(self.uri, ROOM['conversions'])):
            parsed = self.conversionStep(conv)(parsed)

        outputQuadsSets = rx.combine_latest(
            *[self.makeQuads(parsed, plan)
              for plan in g.objects(self.uri, ROOM['graphStatements'])])

        outputQuadsSets.subscribe_(self.updateQuads)

    def topicFromConfig(self, config) -> bytes:
        topicParts = list(config.items(config.value(self.uri, ROOM['mqttTopic'])))
        return b'/'.join(t.encode('ascii') for t in topicParts)


    def subscribeMqtt(self):
        return self.mqtt.subscribe(self.mqttTopic)

    def countIncomingMessage(self, _):
        self._mqttStats.fps.mark()
        self._mqttStats.count += 1

    def getParser(self):
        g = self.config
        parser = g.value(self.uri, ROOM['parser'])
        if parser == XSD.double:
            return rx.operators.map(lambda v: Literal(float(v.decode('ascii'))))
        elif parser == ROOM['tagIdToUri']:
            return rx.operators.map(self.tagIdToUri)
        elif parser == ROOM['onOffBrightness']:
            return rx.operators.map(lambda v: Literal(0.0 if v == b'OFF' else 1.0))
        elif parser == ROOM['jsonBrightness']:
            return rx.operators.map(self.parseJsonBrightness)
        elif ROOM['ValueMap'] in g.objects(parser, RDF.type):
            return rx.operators.map(lambda v: self.remap(parser, v.decode('ascii')))
        else:
            raise NotImplementedError(parser)

    def parseJsonBrightness(self, mqttValue: bytes):
        msg = json.loads(mqttValue.decode('ascii'))
        return Literal(float(msg['brightness'] / 255) if msg['state'] == 'ON' else 0.0)

    def conversionStep(self, conv: Node):
        g = self.config
        if conv == ROOM['celsiusToFarenheit']:
            return rx.operators.map(lambda value: Literal(round(value.toPython() * 1.8 + 32, 2)))
        elif g.value(conv, ROOM['ignoreValueBelow'], default=None) is not None:
            threshold = g.value(conv, ROOM['ignoreValueBelow'])
            return rx.operators.filter(lambda value: value.toPython() >= threshold.toPython())
        else:
            raise NotImplementedError(conv)

    def makeQuads(self, parsed, plan):
        g = self.config
        def quadsFromValue(valueNode):
            return set([
                (self.uri,
                 g.value(plan, ROOM['outputPredicate']),
                 valueNode,
                 self.uri)
            ])

        def emptyQuads(element):
            return set([])

        quads = rx.operators.map(quadsFromValue)(parsed)

        dur = g.value(plan, ROOM['statementLifetime'])
        if dur is not None:
            sec = parseDurationLiteral(dur)
            quads = quads.pipe(
                rx.operators.debounce(sec, rx.scheduler.eventloop.TwistedScheduler(reactor)),
                rx.operators.map(emptyQuads),
                rx.operators.merge(quads),
                )

        return quads

    def updateQuads(self, newGraphs):
        newQuads = set.union(*newGraphs)
        g = graphFromQuads(newQuads)
        log.debug(f'{self.uri} update to {len(newQuads)} statements')

        self.influx.exportToInflux(newQuads)

        self.masterGraph.patchSubgraph(self.uri, g)

    def tagIdToUri(self, value: bytearray) -> URIRef:
        justHex = value.decode('ascii').replace('-', '').lower()
        int(justHex, 16)  # validate
        return URIRef(f'http://bigasterisk.com/rfidCard/{justHex}')

    def remap(self, parser, valueStr: str):
        g = self.config
        value = Literal(valueStr)
        for entry in g.objects(parser, ROOM['map']):
            if value == g.value(entry, ROOM['from']):
                return g.value(entry, ROOM['to'])
        raise KeyError(value)


if __name__ == '__main__':
    arg = docopt("""
    Usage: rdf_from_mqtt.py [options]

    -v        Verbose
    --cs=STR  Only process config filenames with this substring
    """)
    verboseLogging(arg['-v'])

    config = Graph()
    for fn in [
            "config_cardreader.n3",
            "config_nightlight_ari.n3",
            "config_bed_bar.n3",
            "config_air_quality_indoor.n3",
            "config_air_quality_outdoor.n3",
            "config_living_lamps.n3",
            "config_kitchen.n3",
    ]:
        if not arg['--cs'] or arg['--cs'] in fn:
            config.parse(fn, format='n3')

    masterGraph = PatchableGraph()

    mqtt = MqttClient(clientId='rdf_from_mqtt', brokerHost='bang',
                      brokerPort=1883)
    influx = InfluxExporter(config)

    srcs = []
    for src in config.subjects(RDF.type, ROOM['MqttStatementSource']):
        srcs.append(MqttStatementSource(src, config, masterGraph, mqtt, influx))
    log.info(f'set up {len(srcs)} sources')

    port = 10018
    reactor.listenTCP(port, cyclone.web.Application([
        (r"/()", cyclone.web.StaticFileHandler,
         {"path": ".", "default_filename": "index.html"}),
        (r'/stats/(.*)', StatsHandler, {'serverName': 'rdf_from_mqtt'}),
        (r"/graph/mqtt", CycloneGraphHandler, {'masterGraph': masterGraph}),
        (r"/graph/mqtt/events", CycloneGraphEventsHandler,
         {'masterGraph': masterGraph}),
        ], mqtt=mqtt, masterGraph=masterGraph, debug=arg['-v']),
                      interface='::')
    log.warn('serving on %s', port)

    reactor.run()