# -*- coding: utf-8 -*-
import asynchat
import asyncore
import socket
import sys
import logging

import os
from lxml import objectify
from lxml import etree

logger = logging.getLogger("ebus.core")
logger.setLevel(logging.INFO)

class UnknownPacketException(Exception):
    pass

class EbusPacket(object):
    EBUS_SPECIFICATION = os.path.join(os.path.dirname(__file__), "ebus_specification.xml")
    ebus_xml = objectify.parse(open(EBUS_SPECIFICATION))

    @staticmethod
    def address_to_type(address):
        d=[dev.get("type") for dev in EbusPacket.ebus_xml.xpath("/ebus/devices/device[@address=$address]",
                                                                  address="#x%.2x"%address)]
        return len(d)>0 and d[0] or None

    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 __str__(self):
        #XXX self.length only in subclasses
        return "<%-18s name=\"%s\" source=\"0x%.2x\" destination=\"0x%.2x\" primary=0x%x secondary=0x%x length=0x%x>" % \
            (self.__class__.__name__, self.name(), self.source, self.destination, \
             self.primary_command, self.secondary_command, self.length)

    def get_packet_description(self):
        p=EbusPacket.ebus_xml.xpath("/ebus/packets/packet[@primary=$primary and @secondary=$secondary]",
                                      primary="#x%.2x"%self.primary_command,
                                      secondary="#x%.2x"%self.secondary_command)
        if len(p)>0 and p[0] is not None:
            return p[0]
        else:
            raise UnknownPacketException("Unknown Packet, primary_command=#x%.2x secondary_command=#x%.2x" % (
                self.primary_command,
                self.secondary_command))

    def get_source_name(self):
        s=EbusPacket.ebus_xml.xpath("/ebus/devices/device[@address=$address]",
                                      address="#x%.2x"%self.source)
        return len(s)>0 and s[0].get("name") or None

    def get_destination_name(self):
        d=EbusPacket.ebus_xml.xpath("/ebus/devices/device[@address=$address]",
                                      address="#x%.2x"%self.destination)
        return len(d)>0 and d[0].get("name") or None
                                        
    def name(self):
        return self.get_packet_description().get("name")

    def description(self):
        return self.get_packet_description().get("description")


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

        self.data = self.request #XXX

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):
        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 = ""
        self.debug = False

    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,dataRaw):
        #0xaa bug
        i = 0
        data = ""
        while (i+1) < len(dataRaw):
            if ord(dataRaw[i]) == 0xaa and ord(dataRaw[i+1]) == 0x01:
                data += "\xaa"
                i = i + 1
            elif ord(dataRaw[i]) == 0xa9 and ord(dataRaw[i+1]) == 0x00:
                data += "\xa9"
                i = i + 1
            else:
                data += dataRaw[i]
            i = i + 1
        
        if len(data) < 2:
            logger.critical("Daten Gaga")
            return
        source = ord(data[0])
        sourceType = EbusPacket.address_to_type(source)
        destination = ord(data[1])
        destinationType = EbusPacket.address_to_type(destination)

        if len(data) < 9:
            logger.critical("Unvollständige Daten")
            return

        primaryCommand = ord(data[2])
        secondaryCommand = ord(data[3])
        payloadLength = ord(data[4])
        payload = data[5:5+payloadLength]

        if self.debug:
            print "\033[1;31m%.2x %.2x\033[1;m \033[1;33m%.2x %.2x\033[1;m \033[1;30m%.2x\033[1;m \033[1;45m%s\033[1;m" % (
                source,
                destination,
                primaryCommand,
                secondaryCommand,
                payloadLength,
                " ".join(map(lambda byte: "%.2x"%ord(byte), payload)))


        try:
            if sourceType == 'master' and destinationType == 'master':
                p = EbusMasterMaster(source, destination, primaryCommand, secondaryCommand, payload)
                self.handle_ebus(p)
            elif sourceType == 'master' and destinationType == 'slave':
                p = EbusMasterSlave(source, destination, primaryCommand, secondaryCommand, payload, None) #FIXME
                logger.info("SKIP MASTER-SLAVE")
            elif sourceType == 'master' and destinationType == 'broadcast':
                p = EbusBroadcast(source, destination, primaryCommand, secondaryCommand, payload)
                self.handle_ebus(p)
            else:
                logger.warning("SKIP source=%s sourceType=%s destination=%s destType=%s" % \
                    (source, sourceType, destination, destinationType))
        except UnknownPacketException,e:
            print e

    def handle_ebus(self,ebus_packet):
        logger.critical("unhandled ebus_packet")