"""
provide basic class to operate SCPI capable instruments
"""

import re

def response2numStr(strIn, firstSeparator=None, unit=None):
    # Often an instrument reply is in the form 'TDIV 2.00E-08S' (for example Siglent Scope)
    # i.e. "<prefix><firstSeparator><numberString><unit>
    # prefix='TDIV', firstSeparator=' ', numberString='2.00E-08', unit='S'
    # this function parses the reply
    spltStr = re.split(firstSeparator, strIn)
    prefix = spltStr[0]
    rstr = spltStr[1]
    spltStr = re.split(unit, rstr)
    numberString = spltStr[0]
    unit = spltStr[1]
    return (prefix, numberString, unit)


class SCPIinstr:
    """ Basic class which support SCPI commands """
    """     
    Do not instantiate directly, use
    rm = pyvisa.ResourceManager()
    SCPIinstr(rm.open_resource('TCPIP::192.168.0.2::INSTR'))
    """
    def __init__(self, resource):
        self.resource = resource
        
        # convenience pyvisa functions
        self.write = self.resource.write
        self.read = self.resource.read
        self.query = self.resource.query
        self.read_bytes = self.resource.read_bytes
        self.read_binary_values = self.resource.read_binary_values
        self.query_binary_values = self.resource.query_binary_values

    @property
    def idn(self):
        return self.query("*IDN?")

    def clear_status(self):
        self.write("*CLS")

    def set_event_status_enable(self):
        self.write("*ESE")
    
    def query_event_status_enable(self):
        self.query("*ESE?")

    def query_event_status_register(self):
        self.query("*ESR?")

    def set_wait_until_finished(self):
        self.query("*OPC")

    def wait_until_finished(self):
        self.query("*OPC?")

    def reset(self):
        self.write("*RST")
    
    def set_service_request_enable(self):
        self.write("*SRE")

    def query_service_request_enable(self):
        self.query("*SRE?")

    def query_status_byte(self):
        self.query("*STB?")
    
    def self_test_result(self):
        self.query("*TST?")
    
    def wait(self):
        self.write("*WAI")