"""
This unit talks to i-Series controllers sold by Omega and Newport.
They are often can be connected via iServer interface
Specifically, i853 units with LAN connection, but should be ok with many others.

Querying of this controller is slo-o-o-w at least 0.2 second and can be longer.
"""

from qolab.hardware.basic import BasicInstrument
import socket

class I800(BasicInstrument):
    def __init__(self, *args, host='192.168.1.200', port=1000, **kwds):
        """
        host - default hostname or IP of the controller unit (192.168.1.200) is factory default
        port - socket port (1000 by default) which accept HTTP POST requests
        """
        BasicInstrument.__init__(self, *args, **kwds)
        self.host=host
        self.port=port
        self.modbus_address='01'
        self.cmd_start_marker='*'
        self.config['Device type']='TemperatureController'
        self.config['Device model'] = 'i800'
        self.config['FnamePrefix'] = 'temperature'
        self.deviceProperties = {'Temperature', 'SetPoint1', 'SetPoint2'}

    def query(self, cmnd):
        modbus_cmnd = f'{self.modbus_address}{cmnd}'
        qstr=f'POST / HTTP/1.1\r\n\r\n{self.cmd_start_marker}{modbus_cmnd}\r\n'
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((self.host, self.port))
        s.send(qstr.encode('ascii'))
        reply = s.recv(100).decode('ascii')
        if reply[0:5] != f'{modbus_cmnd}':
            # check the proper echo response
            return None
        return reply[5:-1] # last symbol is '\r'

    @BasicInstrument.tsdb_append
    def getTemperature(self):
        command='X01'; # give decimal representation (X) of the temperature (01 address)
        return float(self.query(command))

    def setPoinStr2value(self, spStr):
        raw = int(spStr, 16)
        if raw & (1<<23):
            sign = -1
        else:
            sign = 1

        if raw & (0b1 << 20):
            scale = 1
        elif raw & (0b10 << 20):
            scale = 10
        elif raw & (0b11 << 20):
            scale = 100
        elif raw & (0b100 << 20):
            scale = 100
        else:
            print('Error: unknown decimal point position')
            return None

        val = raw & 0xFFFFF
        return(sign*val/scale)

    @BasicInstrument.tsdb_append
    def getSetPoint1(self):
        command='R01'
        reply=self.query(command)
        return (self.setPoinStr2value(reply))

    @BasicInstrument.tsdb_append
    def getSetPoint2(self):
        command='R02'
        reply=self.query(command)
        return (self.setPoinStr2value(reply))
    
if __name__ == '__main__': 
    tc = I800()
    print(tc.getConfig())