#!/usr/bin/python
# -* coding: utf-8 *-

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Developed 2009-2010 by Bernd Wurst <bernd@schokokeks.org>
# for own use.
# Released to the public in 2012.


import socket, datetime, logging

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Constantes
inverter_types = {
        20010: { 'desc': 'SolarMax 2000S', 'max': 2000, }, # Juste deviner
        20020: { 'desc': 'SolarMax 3000S', 'max': 3000, },
        20030: { 'desc': 'SolarMax 4200S', 'max': 4200, },
        20040: { 'desc': 'SolarMax 6000S', 'max': 6000, },
    }


query_types = [
        'KDY', 'KYR', 'KMT', 'KT0', 'IL1', 'IDC', 'PAC', 'PRL',
        'SYS', 'SAL', 'TNF', 'PAC', 'PRL', 'TKK', 'UL1', 'UDC',
        'ADR', 'TYP', 'PIN', 'MAC', 'CAC', 'KHR', 'EC00', 'EC01',
        'EC02', 'EC03', 'EC04', 'EC05', 'EC06', 'EC07', 'EC08',
        'BDN', 'SWV', 'DIN', 'LAN', 'SDAT', 'FDAT'
    ]

status_codes = {
    20000: 'Pas de communication',
    20001: 'En cours d\'utilisation',
    20002: 'Trop peu de rayonnement',
    20003: 'Démarrage',
    20004: 'Opération sur MPP',
    20005: 'Le ventilateur tourne',
    20006: 'Fonctionnement à puissance maximale',
    20007: 'Limite de température',
    20008: 'Fonctionnement sur secteur',
}

alarm_codes = {
        0: "pas d'erreur",
        1: "Erreur externe 1",
        2: "Erreur d'isolement côté DC",
        4: "Courant de défaut à la terre trop important",
        8: "Rupture du fusible de la protection terre",
       16: "Alarme externe 2",
       32: "Limitation de température à long terme",
       64: "Erreur alimentation CA",
      128: "Alarme externe 4",
      256: "Ventilateur défectueux",
      512: "Casser le fusible",
     1024: "Défaillance du capteur de température",
     2048: "Alarme 12",
     4096: "Alarme 13",
     8192: "Alarme 14",
    16384: "Alarme 15",
    32768: "Alarme 16",
    65536: "Alarme 17",
  }

# Hilfs-Routine (DEBUG)

def DEBUG(*s):
    out = [datetime.datetime.now().isoformat()+':',] + [str(x) for x in s]
    #print(' '.join(out))
    logger.debug(' '.join(out))

def get_status_code(v):
    for i in status_codes:
        if status_codes[i]==v:
            return i
    return None

####################################
## main class
####################################
class SolarMax ( object ):

    def __init__(self, host, port):
        self.__host = host
        self.__port = port
        self.__inverters = {}
        self.__socket = None
        self.__connected = False
        self.__allinverters = False
        self.__inverter_list = []
        self.__connect()

    def __repr__(self):
        return 'SolarMax[%s:%s / socket=%s]' % (self.__host, self.__port, self.__socket)

    def __str__(self):
        return 'SolarMax[%s:%s / socket=%s / inverters=%s]' % (self.__host, self.__port, self.__socket, self.inverters())

    def __disconnect(self):
        try:
            DEBUG('Closing open connection to %s:%s' % (self.__host, self.__port))
            self.__socket.shutdown(socket.SHUT_RDWR)
            self.__socket.close()
            del self.__socket
        except:
            pass
        finally:
            self.__connected = False
            self.__allinverters = False
            self.__socket = None

    def __del__(self):
        DEBUG('destructor called')
        self.__disconnect()

    def __connect(self):
        self.__disconnect()
        DEBUG('establishing connection to %s:%i...' % (self.__host, self.__port))
        try:
            self.__socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

            self.__socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

            s = self.__socket
            s.settimeout(2)
            s.connect((self.__host, self.__port))
            s.settimeout(10)

            self.__connected = True
            DEBUG('connected.')
        except:
            DEBUG('connection to %s:%i failed' % (self.__host, self.__port))
            self.__connected = False
            self.__allinverters = False


    # Utility-functions
    def hexval(self, i):
        return (hex(i)[2:]).upper()


    def checksum(self, s):
        total = 0
        for c in s:
            total += ord(c)
        h = self.hexval(total)
        while len(h) < 4:
            h = '0'+h
        return h

    def __read_char(self):
        byte = self.__socket.recv(1)
        if len(byte) > 0:
            return ord(byte) & 0x7F
        return 0

    def __receive(self):
        try:
            data = []
            while True:
                c = self.__read_char()
                if c:
                    data.append(chr(c))
                if not c or chr(c) == '}':
                    break
            return ''.join(data)

        except:
            self.__allinverters = False
            return ''


    def __parse(self, answer):
        # convenience checks
        if answer[0] != '{' or answer[-1] != '}':
            raise ValueError('malformed answer: %s' % answer)
        raw_answer = answer
        answer = answer[1:-1]
        checksum = answer[-4:]
        content = answer[:-4]
        # checksum
        if checksum != self.checksum(content):
            raise ValueError('checksum error')

        (header, content) = content[:-1].split('|', 2)
        (inverter, fb, length) = header.split(';', 3)
        if fb != 'FB':
            raise ValueError('answer not understood')
        # length
        length = int(length, 16)
        if length != len(raw_answer):
            raise ValueError('length mismatch')

        inverter = int(inverter)

        # Bei schreibzugriff antwortet der WR mit 'C8'
        # Avec un accès en écriture, le WR répond par 'C8'
        #if not content.startswith('64:'):
        #  raise ValueError('Inverter did not understand our query')

        content = content[3:]
        data = {}

        for item in content.split(';'):
            (key, value) = item.split('=')
            if key not in query_types:
                raise NotImplementedError("Don't know %s" % item)
            data[key] = value
        return (inverter, data)


    def __build_query(self, idn, values, qtype=100):
        qtype = self.hexval(qtype)
        if type(values) == list:
            for v in values:
                if v not in query_types:
                    raise ValueError('Unknown data type »'+v+'«')
            values = ';'.join(values)

        #elif type(values) in [str, unicode]:
        elif type(values) in [str,]:
            pass
        else:
            raise ValueError('value has unsupported type')

        querystring = '|' + qtype + ':' + values + '|'
        # Länge vergrößern um: 2 x { (2), WR-Nummer (2), "FB" (2), zwei Semikolon (2), Länge selbst (2), checksumme (4)
        # Augmentez la longueur de : 2 x { (2), le numéro WR (2), "FB" (2), deux points-virgules (2), la longueur elle-même (2), la somme de contrôle (4)
        l = len(querystring) + 2 + 2 + 2 + 2 +2 + 4
        querystring = 'FB;%02i;%s%s' % (int(idn), self.hexval(l), querystring)
        querystring += self.checksum(querystring)
        return '{%s}' % querystring


    def __send_query(self, querystring):
        try:
            DEBUG(self.__host, '=>', querystring)
            #self.__socket.send(querystring)
            self.__socket.send(querystring.encode())
        except socket.timeout:
            self.__allinverters = False
            self.__connected = False


    def query(self, idn, values, qtype=100):
        q = self.__build_query(idn, values, qtype)
        DEBUG("WR %i: %s" % (idn, q))

        self.__send_query(q)
        answer = self.__receive()

        if answer:
            (inverter, data) = self.__parse(answer)
            for d in data.keys():
                data[d] = self.normalize_value(d, data[d])
            return (inverter, data)
        else:
            self.__allinverters = False

        if not self.__allinverters and not self.__detection_running:
            self.detect_inverters()
        elif not self.__connected:
            self.__connect()
        else:
            raise socket.timeout
        return None


    def normalize_value(self, key, value):
        if key in [ 'KDY', 'UL1', 'UDC']:
            return float(int(value, 16)/10)

        elif key in [ 'IL1', 'IDC', 'TNF', ]:
            return float(int(value, 16)/100)

        elif key in [ 'PAC', 'PIN', ]:
            return float(int(value, 16)/2)

        elif key in [ 'SAL', ]:
            return int(value, 16)

        elif key in [ 'SYS', ]:
            (x,y) = value.split(',',2)
            x = int(x, 16)
            y = int(y, 16)
            return (x,y)

        elif key in [ 'SDAT', 'FDAT' ]:
            (date, time) = value.split(',',2)
            time = int(time, 16)
            return datetime.datetime(int(date[:3], 16), int(date[3:5], 16), int(date[5:], 16), time//3600, (time % 3600) // 60, time % (3600*60))
        else:
            return int(value, 16)


    def write_setting(self, inverter, data):
        rawdata = []
        for key,value in data.iteritems():
            key = key.upper()
            if key not in query_types:
                raise ValueError('unknown type')
            value = self.hexval(value)
            rawdata.append('%s=%s' % (key, value))

        DEBUG(self.query(inverter, ';'.join(rawdata), 200))


    def status(self, inverter):
        result = self.query(inverter, ['SYS', 'SAL'])
        if not result:
            return ('Offline', 'Offline')

        result = result[1]
        errors = []
        if result['SAL'] > 0:
            for (code, descr) in alarm_codes.iteritems():
                if code & result['SAL']:
                    errors.append(descr)

        status = status_codes[result['SYS'][0]]

        return (status, ', '.join(errors))


    def use_inverters(self, list_of):
        self.__inverter_list = list_of
        self.detect_inverters()


    def detect_inverters(self):
        self.__inverters = {}
        if not self.__connected:
            self.__connect()

        self.__detection_running = True
        for inverter in self.__inverter_list:
            try:
                DEBUG('searching for #%i (socket: %s)' % (inverter, self.__socket))
                (inverter, data) = self.query(inverter, [ 'ADR', 'TYP', 'PIN' ])

                if data['TYP'] in inverter_types.keys():
                    self.__inverters[inverter] = inverter_types[data['TYP']].copy()
                    self.__inverters[inverter]['installed'] = data['PIN']
                else:
                    DEBUG('Unknown inverter type: %s (ID #%i)' % (data['TYP'], data['ADR']))

            except Exception as e:
                DEBUG('Inverter #%i not found: %s' % (inverter, e))

                self.__allinverters = False

        self.__detection_running = False

        if len(self.__inverters) == len(self.__inverter_list):
            self.__allinverters = True
            DEBUG('found all inverters:')
            DEBUG(self.__inverters)
        else:
            DEBUG('not all invertes found, reconnection!')
        self.__connect()


    def inverters(self):
        if not self.__allinverters:
            self.detect_inverters()
        return self.__inverters