'''
Created on 05.12.2013

@author: Philipp Rauch
'''
from pymodbus.client.sync import ModbusTcpClient
from datetime import datetime
from profile.datasheet import Datasheet
import struct

def setup(conf):
    PACS = []
    csv = '%s/%s' % (conf['config_dictionary'], conf['pac_csvfile'])

    pac_csv = Datasheet()
    pac_csv.loadDatasheet(strFile = csv)
    messages = pac_csv.readDatasheet()

    ### INITIALIZE ###
    PACS.append(messages)
    for ip in conf['pac_ip']:
        PACS.append(ModbusTcpClient(ip))

    ### CONNECT ###
    for PAC in PACS[1::]:
        PAC.connect()

    return PACS

def loop(PACS, item):

    row = PACS[0][PACS[0]['offset'] == item]
    inx = row.index.values[0]

    #print row.get('value - type')[inx]
    valType = row.get('value - type')[inx]
    reg = row.get('size (Byte)')[inx]/2

    type_picker = {'double' : _to_double,
                   'float' : _to_float,
                   'float + timestamp' : _to_float_time,
                   'long' : _to_long,
                   'timestamp' : _to_time_abs,
                   'Unsigned long' : _to_ulong,
                   'Unsigned short' : _to_ushort }

    func = type_picker.get(valType, None)
    if func is None:
        raise NotImplementedError

    res = PACS[2].read_holding_registers(item,reg,unit=1)
    return { row.get('Value name')[inx] : func(res.registers) }


def _to_float_time(reg):
    res = { 'value' : _to_float(reg[0:2]) }
    res.update({ 'time' : _to_time_abs(reg[2:6]) })
    return res

def _to_long(reg):
    tmp = _to_ulong(reg)
    s = struct.pack('=i', tmp)
    return struct.unpack('=l', s)[0]

def _to_double(reg):
    tmp = int(reg[0]) << 3*16 | int(reg[1]) << 2*16 | int(reg[2]) << 16 | int(reg[3])
    s = struct.pack('=q', tmp)
    return struct.unpack('=d', s)[0]

def _to_time_abs(reg):
    timestamp = _to_ulong(reg)
    date = datetime.fromtimestamp(timestamp)
    return str(date)

def _to_ulong(reg):
    return int(reg[0]) << 16 | int(reg[1])

def _to_ushort(reg):
    return reg[0]

def _to_float(reg):
    tmp = _to_ulong(reg)
    s = struct.pack('=i', tmp)
    return struct.unpack('=f', s)[0]

def close(PACS):
    ### CLOSE ###
    for PAC in PACS[1::]:
        PAC.close()