# -*- coding:utf8 -*-
import asynchat
import asyncore
import socket
import sys

deviceDescription = [
    {'address':0x03, 'type':'master', 'description':'Feuerungsautomat'},
    {'address':0x10, 'type':'master', 'description':'Heizungsregler #2'},
    {'address':0x30, 'type':'master', 'description':'Heizkreisregler 1'},
    {'address':0x70, 'type':'master', 'description':'Heizkreisregler 2'},
    {'address':0x71, 'type':'master', 'description':'Heizungsregler #9'},
    {'address':0xf1, 'type':'master', 'description':'Heizungsregler #10'},
    {'address':0x50, 'type':'slave', 'description':'Mischer 1'},
    {'address':0x51, 'type':'slave', 'description':'Mischer 2'},
    {'address':0x90, 'type':'slave', 'description':'Raumgeräte/Fernsteller 1'},
    {'address':0x91, 'type':'slave', 'description':'Raumgeräte/Fernsteller 2'},
    {'address':0xfe, 'type':'broadcast', 'description':'Broadcast'},
]

"""ebus specific data field formats"""
class fields:
    class DataField(object):
        def __init__(self, offset):
            self.offset = offset
        def value(self,data):
            raise NotImplemented()

    class Data2c(DataField):
        """
        Beispiel für die Berechnung:
            if ((x & 8000h) == 8000h) // y negativ
                y = - [dez(High_Byte(!x)) 16 + dez(High_Nibble (Low_Byte (!x)))
                    + (dez(Low_Nibble (Low_Byte (!x))) +1 ) / 16]
            else                       // y positiv
                y = dez(High_Byte(x)) 16 + dez(High_ Nibble (Low Byte (x)))
                    + dez(Low_ Nibble (Low Byte (x))) / 16
        """
        def value(self,data):
            highByte = ord(data[self.offset+1])
            lowByte= ord(data[self.offset])
            if (0x8000 & (highByte<<8 | lowByte)) == 0x8000:
                return (-1) * ( (0xff^highByte)*16 + (0xf^(lowByte>>4)) + (0x0f^(0x0&flowByte) + 1)/16.0 )
            else:
                return highByte*16 + (lowByte>>4) + (lowByte&0xf)/16.0

    class Data2b(DataField):
        """
        if ((x&8000h) == 8000h) // y negativ
              y = - [dez(High_Byte(!x)) + (dez(Low_Byte(!x)) + 1) / 256]
        else                        // y positiv
              y = dez(High_Byte (x)) + dez(Low_Byte (x)) / 256
        """
        def value(self,data):
            highByte = ord(data[self.offset+1])
            lowByte= ord(data[self.offset])
            if (0x8000 & (highByte<<8 | lowByte)) == 0x8000:
                return (-1) * ((0xff^highByte) + (0xff^lowByte+1)/256.0)
            else:
                return highByte + lowByte/256.0

    class Bit(DataField):
        def value(self, data):
            return ord(data[self.offset]) == 0x1

    class ByteEnum(DataField):
        def __init__(self, offset, values):
            self.values = values
            fields.DataField.__init__(self, offset)
        def value(self, data):
            value = ord(data[self.offset])
            if self.values.has_key(value):
                return self.values[value]
            else:
                return None

packetDescription = [
     # Service 0x05 (Brennersteuerbefehle)
     {'primary':0x5,  'secondary':0x3, 'name':'Betriebsdaten des Feuerungsautomaten an den Regler Block1'},
     {'primary':0x5,  'secondary':0x7, 'name':'Betriebsdaten des Reglers an den Feuerungsautomaten','format': {
        'betriebszustand':fields.ByteEnum(0, {
            0x00:'Brenner Abschalten', 
            0x01:'Keine Aktion', 
            0x55:'Brauchwassbereitung', 
            0xaa:'Heizbetrieb',
            0xcc:'Emmissionskontroll',
            0xdd:'TÜV-Funktion',
            0xee:'Regler Stopp',
            0x66:'Brauchwasserbereitung bei Reglerstoppfunktion',
            0xbb:'Brauchwasserbereitung bei Heizbetrieb',
            0x44:'Reglerstoppfunktion bei stufigem Betrieb'}),
        'betriebszustand2':fields.ByteEnum(1, {
            0x00:'Keine Aktion',
            0x01:'Ausschalten Kesselpumpe',
            0x02:'Einschalten Kesselpumpe',
            0x03:'Ausschalten variable Verbraucher',
            0x04:'Einschalten variabler Verbraucher'}),
        'kesselSollwertTemperatur':fields.Data2c(2),
        'kesselSollwertDruck':fields.Data2b(4),
        }},
     # Service 0x07 (Systemdatenbefehle)
     {'primary':0x7,  'secondary':0x0, 'name':'Datum/Zeit - Meldung eines eBUS Masters'},
     {'primary':0x7,  'secondary':0x4, 'name':'Identifikation'},
     # Service 0x08 (Reglerbefehle)
     {'primary':0x8,  'secondary':0x0, 'name':'Sollwertübertragung des Reglers an andere Regler'},

     #  Response
     #p[0] = Einheit (1=>Liter, 2=>Kubik)
     #p[1] = 10^0
     #p[2] = 10^2
     #p[3] = 10^4
     #p[4] = 10^6
     {'primary':0x3,  'secondary':0x8, 'name':'Gesamtbrennstoffmengenzähle lesen'},
     {'primary':0x50, 'secondary':0x17, 'name':'Solar Daten', 'format':{
        'solarPumpe':fields.Bit(0), 
        'tempKollektor':fields.Data2c(2), 
        'tempWarmwasserSolar':fields.Data2c(4)}},
]

def formatHex(data):
    return " ".join(map(lambda byte: "%.2x"%ord(byte), data))

def getDsc(address):
    dev=filter(lambda dev: dev['address'] == address, deviceDescription)
    if len(dev)>0:
        return dev[0]['description']
    else:
        return None

class EbusPacket(object):
    def __init__(self, source, destination, primary_command, secondary_command):
        self.source = source
        self.destination = destination
        self.primary_command = primary_command
        self.secondary_command = secondary_command

    def name(self):
        if self.description():
            return self.description()['name']

    def __str__(self):
        #XXX self.length only in subclasses
        return "<%-18s name=\"%-15s\" source=\"%s\" destination=\"%s\" primary=0x%x secondary=0x%x length=0x%x %s>" % \
            (self.__class__.__name__, self.name(), getDsc(self.source), getDsc(self.destination), \
             self.primary_command, self.secondary_command, self.length, \
             " ".join(map(lambda name: "%s=%s" % (name, self.values()[name]),self.values())))

    def description(self):
        desc = filter(lambda p: p['primary'] == self.primary_command \
            and p['secondary'] == self.secondary_command, packetDescription)
        if len(desc) > 0:
            return desc[0]
        else:
            return None

    def values(self):
        desc = self.description()
        if not desc or not desc.has_key('format'):
            return dict()
        else:
            #XXX self.data only in subclass
            return dict( map(lambda name: (name, desc['format'][name].value(self.data) ), desc['format'].keys()) )

class EbusMasterMaster(EbusPacket):
    def __init__(self, source, destination, primary_command, secondary_command, data):
        EbusPacket.__init__(self, source, destination, primary_command, secondary_command)
        self.length = len(data)
        self.data = data

class EbusMasterSlave(EbusPacket):
    def __init__(self, source, destination, primary_command, secondary_command, request, response):
        EbusPacket.__init__(self, source, destination, primary_command, secondary_command)
        self.length = len(request)
        self.request = request
        self.response = response

class EbusBroadcast(EbusPacket):
     def __init__(self, source, destination, primary_command, secondary_command, data):
        EbusPacket.__init__(self, source, destination, primary_command, secondary_command)
        self.length = len(data)
        self.data = data


class EbusReader(asynchat.async_chat):
    def __init__(self):
        self.buffer = ""

        asynchat.async_chat.__init__(self)
        self.set_terminator("")
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.connect(("10.2.2.200", 7970))

        self.packetIndex = 0
        self.buf = ""

    def collect_incoming_data(self,data):
        for it in range(len(data)):
            if data[it] == "\xaa":
                if it+1 < len(data) and data[it+1] != "\xaa":
                    self._parse(self.buf)
                    self.buf = ""
                    self.packetIndex = 0
            else:
                self.buf += data[it]
                self.packetIndex = self.packetIndex + 1
                #print "%.2x [%d]" % (ord(data[it]),self.packetIndex)

    def _parse(self,data):
        if len(data) < 2:
            print >>sys.stderr, "GAGA"
            return
        source = ord(data[0])
        destination = ord(data[1])

        sourceDevice = filter(lambda dev: dev['address'] == source, deviceDescription)
        destinationDevice = filter(lambda dev: dev['address'] == destination, deviceDescription)
        if len(sourceDevice) == 0 or len(destinationDevice) == 0:
            print >>sys.stderr, "Unbekanntes Paket: source=%x destination=%x" % (source, destination)
            return

        if len(data) < 9:
            print >>sys.stderr, "Unvollständige Daten"
            return

        primaryCommand = ord(data[2])
        secondaryCommand = ord(data[3])
        payloadLength = ord(data[4])
        payload = data[5:6+payloadLength]
    #delete 0x50 packets for devel
    #if (primaryCommand == ord("\x50")):
#       return
    #print "PR SC NN D0 D1 D2 D3 D4 D5 D6 D7 ..."
    #print "%.2x" % (primaryCommand,)
    #print "%.2x %.2x %.2x %s" % (primaryCommand,secondaryCommand,payloadLength,"bla")
    #print "%.2x %.2x %.2x %s" % (primaryCommand,secondaryCommand,payloadLength,formatHex(payload))

        p = None
        if sourceDevice[0]['type'] == 'master' and destinationDevice[0]['type'] == 'master':
            p = EbusMasterMaster(source, destination, primaryCommand, secondaryCommand, payload)
            self.handle_ebus(p)
        elif sourceDevice[0]['type'] == 'master' and destinationDevice[0]['type'] == 'slave':
            p = EbusMasterSlave(source, destination, primaryCommand, secondaryCommand, payload, None) #FIXME
            self.handle_ebus(p)
        elif sourceDevice[0]['type'] == 'master' and destinationDevice[0]['type'] == 'broadcast':
            p = EbusBroadcast(source, destination, primaryCommand, secondaryCommand, payload)
            self.handle_ebus(p)
        else:
            print >>sys.stderr, "KOMISCHES ZEUG"
            return

    def handle_ebus(self,ebus_packet):
        print >>sys.stderr, "unhandled ebus_packet"