'''
Created on Dec 4, 2015
Class to facilitate working with a list of EPICS PVs. 
Inherits from list class to extend the functionality of list. 

@author: Hovanes Egiyan
'''
import time
import sys
import math 

from java.lang import Thread, Runnable

from EpicsPV import EpicsPV

class EpicsPVSet(dict):
    '''
    Class to facilitate working with a list of EPICS PVs. 
    Inherits from list class to extend the functionality of list. 
    '''
    sleepTime = 0.06       # Sleep time 
    maxAttempts = 1000     # Number of attempts to connect this PV    

    def __init__(self, pvNames, varType="double", connectType = "ASYNC" ):
        '''
        Constructor
        '''
        # First call the constructor of super class 
        # to create an empty dictionary.
        super(EpicsPVSet, self).__init__({})
        # Loop through names and create EpicsPV objects. 
        for pvName in pvNames:
            self[pvName] = EpicsPV( pvName, varType, connectType )
        return  
   
    def destroy(self):
        '''
        Disconnect all PVs and clear the dictionary
        '''
        self.disconnect()
        self.clear()
        return
   
    def connect(self):
        '''
        Connect the PVs
        '''
        for pvName in self.keys():
            self[pvName].connect()
        return
    
    def disconnect(self):
        ''' 
        Disconnect all PVs
        ''' 
        for pvName in self.keys():
            self[pvName].disconnect()
        return
    
    def __del__(self):
        self.disconnect()
        super(EpicsPVSet, self).__del__()
        return
    
    def __repr__(self): 
        for pvName in self.keys():
            msg += self[pvName].__repr__()
        return msg     
  
    def __str__(self): 
        for pvName in self.keys():
            msg += self[pvName].__str__()
        return msg     
    
    def areConnected(self):
        allConnected = True
        for pvName in self.keys():
            if( not self[pvName].isConnected() ) :
                return False
        return True
    
    def ensureConnected(self):
        '''
        Wait for all PVs to get connected. Return false if it takes too long.
        Return True when all PVs are connected
        '''
        if self.areConnected(): return True
        # Keep trying to connect
        attemptNumber = 0
        while( not self.areConnected() and (attemptNumber < EpicsPVSet.maxAttempts) ):
            time.sleep( EpicsPVSet.sleepTime )
            attemptNumber += 1
        # If the number of maximum attempts is exceeded raise an exception
        if( attemptNumber >= EpicsPVSet.maxAttempts ):
            return False
        return True
        
   
    def readValues(self):
        ''' 
        Read all PVs in this set
        '''
        for pvName in sorted( self.keys() ):
            self[pvName].readValue()
        return  
    
    def setValue(self, value):
        '''
        Set the same value to all PVs in this set
        '''
        if self.ensureConnected():
            for pvName in self.keys():
                self[pvName].setValue( value )
        return
    
    def setValueAsync(self, value ):
        '''
        Set single value to all PVs asynchronously
        '''
        for pvName in self.keys():
            self[pvName].setValueAsync( value )
        return   
    
    
    def setValues(self, valueMap):
        '''
        Set values based on the map of value
        '''
        if self.ensureConnected():
            for pvName in self.keys():
                if pvName in valueMap.keys():
                    self[pvName].setValue( valueMap[pvName] )
        return

    def setValuesAsync(self, valueMap):
        '''
        Set values based on the map of value
        '''        
        for pvName in self.keys():
            if pvName in valueMap.keys():
               self[pvName].setValueAsync( valueMap[pvName] )
        return
    
    def printItems(self):
        for pvName in sorted(self):
            print self[pvName] 
        return


class testEpicsPVSet(Runnable):
    ''' 
    Class for testing the EpicsPVSet in a separate thread
    so that when launched from CSS it does not block the main thread
    '''
    def __init__(self, nPV, val ):
        self.numberOfPVs = nPV
        self.value = val
        return
    
    def run(self):
        pvNameList = []
        for iPV in range(0, self.numberOfPVs ) :
            pvNameList.append( "testEpicsPV:" + str(iPV) )
    
        pvSet = EpicsPVSet( pvNameList, "double", "ASYNC" )
        pvSet.connect()
        pvSet.setValueAsync(self.value)
        pvSet.readValues()
#        time.sleep(10)
        pvSet.printItems()
        pvSet.destroy()
        return

if __name__ == '__main__':    
    thread = Thread( testEpicsPVSet( 2000, 1100000 ) )
    thread.start()