'''Peripheral Dependent Classes for specific instruments.'''
from gpyb import CommonGPIB, InterfaceGPIB, PeripheralGPIB, lib, status_tags

import thread
import string
from scipy import gplt
from time import sleep, time

esr_tags={'7':('PON','Power ON. Instrument has been turned off and turned back on since the last time this register has been read'),
    '6':('URQ','User Request. LOCAL key on the front panel was pressed.'),
    '5':('CME','Command Error. (ieee syntax error, semantic error, GET inside program message)'),
    '4':('EXE','Execution Error.'),
    '3':('DDE','Device-dependent error due to some internal condition.'),
    '2':('QYE','Query Error. Data red from an empty output queue.'),
    '1':('','Not used.'),
    '0':('OPC','Operation Complete. Ready for new commands.')}


class ScpiGPIB(PeripheralGPIB):
    '''Common methods for SCPI devices.'''
    def disp(self,msg):
        """Display a one-shot short message (disp max 7 digits)"""
        ln=len(msg)+17
        lib.ibwrt(self.ud,'disp:text:stat 1',16)
        self.ibsta=lib.ibwrt(self.ud,'disp:text:data "'+msg[:6]+'"',ln)
        return self.ibsta

    def displ(self,msg):
        """Display a long message by splitting it into <8 pieces. 
        To be started in a new thread! Returns last writing ibsta."""
        lib.ibwrt(self.ud,'disp:text:stat 1',16)
        smsg=''
        msgs=[]
        for lettera in msg:
            smsg=smsg+lettera
            if len(smsg)==7:
                msgs=msgs+[smsg]
                smsg=''
        msgs=msgs+[smsg]
        for smsg in msgs:
            self.ibsta=lib.ibwrt(self.ud,'disp:text:data "'+smsg+'"',len(smsg)+17)
            if self.ibsta!=8448:
                print 'Error sending data to device. Breaking'
                break
            sleep(1)
        self.udisp()
        return self.ibsta
    
    def udisp(self):
        '''Disable text display'''
        self.ibsta=lib.ibwrt(self.ud,'disp:text:stat 0',16)
        return self.ibsta
    def report_esr(self):
        '''Read 'Event Status Register' from device 'dev' and reports it verbosely. 
        Returns         print 'Sending custom commands to EI'
        for cmd in self.eicm:
            if cmd!='read':
                self.fra.wrt(cmd)
                print 'Sent '+cmd+': status: '+str(self.ei.ibsta)
            else: 
                red=self.ei.rd()
                print 'Read command performed on EI bus:\n'+str(red[0])
                print 'Status: '+str(self.ei.ibsta)
the binary string representation of the ESR number.'''
        self.esr=int(self.write_read(self,'*esr?')[0].replace('\n',''))
        s=''
        while self.esr:
            s = str(self.esr % 2) + s
            self.esr/=2
        l=len(s)
        if l<16:
            n=16-l
            s='0'*n+s
        print 'ESR code %s' % s
        
        index=0
        for tag in s:
            if tag=='1':
                print esr_tags[str(index)][0]+'\t'+esr_tags[str(index)][1]
            index+=1
            if index>=7:
                break
        return s
    def cycle_read(self,measure,iterations):
        '''This function iterates one-shot reading of the configured function 'measure' (eg: volt:dc). 
        Returns a list of tuples ('time of reading','reading')'''
        data=[]
        self.wrt('conf:'+measure)
        i=0
        itime=time()
        while i<=iterations:
            data=data+[(time()-itime,string.atof(self.write_read('read?')[0].replace('\n','')))]
            i+=1
        return data
    
    def cycle_plot(self,measure,iterations):
        '''As cycle_reads, but also plots the results.'''
        data=self.cycle_read(measure,iterations)
        x=[]
        y=[]
        for xy in data:
            x+=[xy[0]]
            y+=[xy[1]]
        gplt.plot(x,y)
        gplt.title('Volt vs time plot')
        gplt.xtitle('Time (seconds)')
        gplt.ytitle('Volt, DC')
        return data

####################################    
class k2kV(ScpiGPIB):
    '''Keithley Model 2000 Voltmeter methods'''
    def cyvolt(self, iterations):
        '''Cycle read DC voltage and plots the result'''
        self.cycle_plot('volt:dc',iterations)

####################################