# -*- coding: cp1252 -*-
'''
Created on 11.10.2011

@author: sth2mt
'''
GPIO_DIRECT_OUT = True
GPIO_DIRECT_IN = False

class Treiber(object):
    '''
    classdocs
    '''
    stout = False

    def __init__(self,i_Pin,b_Direction,b_Val=False):
        '''
        Constructor
        '''
        self.printf( "Gpio_CL\n")
        self.i_PinNr = i_Pin
        self.b_Direction = b_Direction
        self.i_ERROR=0
        self.a_c_ExportFilePath = "/sys/class/gpio/export"
        self.a_c_UnexportFilePath = "/sys/class/gpio/unexport"
        self.a_c_PinFilePath = "sys/class/gpio%d"
        self.a_c_PinValuePath = "/sys/class/gpio/gpio%d/value"
        self.a_c_PinDirectionPath = "/sys/class/gpio/gpio%d/direction"
        self.a_c_File = None
        self.F_PinValueFile = file
        self.GPIO_DIRECT_OUT = True
        self.GPIO_DIRECT_IN = False



        #self.f_WriteUnexportFile()
        #print "Pin in /sys/class/gpio/export File eintragen"
        if self.f_WriteExportFile()!=0:
            self.i_ERROR=-1
            return None
        
        #print"Direction festlegen"
        if self.f_SetDirection(self.b_Direction)!=0:
            self.i_ERROR=-2
            return None
        
        #print"Pin Value File oeffnen"
        if self.f_OpenPinValueFile()!=0:
            self.i_ERROR=-3
            return self.i_ERROR
        #print "Wert setzen"
        if self.b_Direction == self.GPIO_DIRECT_OUT:
            if self.f_WritePin(b_Val)!=0:
                self.i_ERROR=-4
                return None
        pass
        
            
    def __del__(self):
        self.printf( "~Gpio_CL\n")
        #self.f_WriteUnexportFile()
        '''
        Destructor
        '''
        if not self.F_PinValueFile.closed:
            self.F_PinValueFile.close()
        self.printf( "~Gpio_CL Ende\n")
        pass

    def f_OpenPinValueFile(self):
        self.a_c_File = self.a_c_PinValuePath % self.i_PinNr
        try:
            self.F_PinValueFile = open(self.a_c_File,"w+")
            return 0
        except IOError,e:
            print "Gpio.f_OpenPinValueFile()", e
            return -1
        pass
    
    def f_ReadPin(self):
        if self.F_PinValueFile.closed:
            self.f_OpenPinValueFile()
        try:
            c_Value = self.i_PinValueFile.read(1)
            return (c_Value=='1')
        except IOError,e:
            print "Gpio.f_ReadPin()", e
            return -1
        pass
    
    def f_WritePin(self,b_Val):
        c_Val= "%d" % b_Val
#
        if self.F_PinValueFile.closed:
            self.f_OpenPinValueFile()
        try:
            #print self.PinValueFile
            #print "Pin %d -> %s" % (self.i_PinNr,c_Val)
            #self.F_PinValueFile = open ("Test","w")
            self.F_PinValueFile.write(c_Val)
            return 0
        except IOError,e:
            print "Gpio.f_WritePin()", e
            return -1
            
        pass
    
    
    def f_WriteExportFile(self):
        try:
            File = open(self.a_c_ExportFilePath,"w")
            s_Buf = "%d" % self.i_PinNr
            File.write(s_Buf)
            File.close()
            return 0
        except (IOError), e:
            #print "Gpio.f_WriteExportFile(%s %s)" % (self.a_c_ExportFilePath,s_Buf), e
            if e.args[0] == 22:
                print "Gpio.f_WriteExportFile(%s %s)" % (self.a_c_ExportFilePath,s_Buf), e
                print " GPIO nicht vorhanden"
            return -1
        pass

    def f_WriteUnexportFile(self):
        try:
            File = open(self.a_c_UnexportFilePath,"w")
            s_Buf = "%d" % self.i_PinNr
            File.write(s_Buf)
            File.close()
            return 0
        except (IOError), e:
            print "Gpio.f_WriteUnexportFile()", e
            if e.args[0] == 22:
                print " GPIO nicht vorhanden"
            return -1
        
    
    def f_SetDirection(self,b_Direction):
        if b_Direction:
            s_Buf = "out"
        else:
            s_Buf = "in"
        
        self.b_Direction = b_Direction

        a_c_File = self.a_c_PinDirectionPath % self.i_PinNr
        #print a_c_File,s_Buf
        
        try:
            File = open(a_c_File,"w")
            File.write(s_Buf)
            File.close()
            return 0
        except (IOError), e:
            print "Gpio.f_SetDirection()", e
            return -1

    def printf(self,string):
        if Treiber.stout:
            print string
        pass