'''
Created on 05.12.2013

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

_csv_lookup = { 'offset' : 'offset',
                'type' : 'value - type',
                'size' : 'size (Byte)',
                'name' : 'Value name',
                'time_offset' : 797}

def setup(conf):
    '''
    load message definition and connect to all pacs
    '''
    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)
    if isinstance(conf['pac_ip'], list):
        for ip in conf['pac_ip']:
            PACS.append(ModbusTcpClient(ip))
    else:
        PACS.append(ModbusTcpClient(conf['pac_ip']))

    ### CONNECT ###
    for PAC in PACS[1::]:
        PAC.connect()
        _set_time(PAC, _csv_lookup['time_offset'])

    return PACS

def loop(PACS, item):
    '''
    get value of message and convert it to the right datatype
    return the result
    '''

    row = PACS[0][PACS[0][_csv_lookup['offset']] == item[1]]
    inx = row.index.values[0]

    #print row.get('value - type')[inx]
    valType = row.get(_csv_lookup['type'])[inx]
    reg = row.get(_csv_lookup['size'])[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[item[0]].read_holding_registers(item[1], reg, unit=1)
    return { row.get(_csv_lookup['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 numpy.float32(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 numpy.float64(struct.unpack('=d', s)[0])

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

def _to_ulong(reg):
    return numpy.int32(reg[0]) << 16 | int(reg[1])

def _to_ushort(reg):
    return numpy.int16(reg[0])

def _to_float(reg):
    tmp = _to_ulong(reg)
    s = struct.pack('=i', tmp)
    return numpy.float32(struct.unpack('=f', s)[0])

def _set_time(PAC, offset):
    stamp = time.time()
    high = int(int(stamp) >> 16)
    low = int(int(stamp) & int(0xFFFF))
    PAC.write_registers(offset, (high, low, 0, 0), unit=1)

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