'''
PSI class to interact with arduino
Read capacitance of FC100 cell
'''

import os
import time
import serial

class psiSerial(serial.Serial):
    def __init__(self,**kwargs):
        super(psiSerial,self).__init__(**kwargs)
        # Default values
        #self.port='COM8'
        #self.baudrate=9600
        #self.bytesize=8
        #self.bitstop=1
        #self.parity='N'
        self.timeout=0.1 # Read timeout of 0.1s default
        self.customConnectionError = b'DEVICE CONNECTION ERROR\r\n'
        self.maxAttempts = 10
        self.sleep_after_open = 0.1 #s
        self.endOfLine = "\r"
        self.writeWhileEmpty = False
    
    def psi_open(self,**kwargs):
        self.custom_is_open = False
        while not self.custom_is_open:
            try:
                self.open()
            except:
                ''
            if self.is_open:
                a=self.readline()
                if a != self.customConnectionError:
                    self.custom_is_open = True
                else:
                    self.close()
        print('Serial port is open. Wait for',self.sleep_after_open,'seconds.')
        time.sleep(self.sleep_after_open)
    
    def psi_write(self,string,**kwargs):
        '''
        IN: string
        OUT:    serial.Serial.write(bstring)
                where bstring is a string decorated by
                "b'" +string+"\r\n".

        Opt.:   book write_debug: writes the input string and output
                encoded string.
        '''
        try:
            self.write_debug = kwargs['write_debug']
        except:
            self.write_debug = False
        try:
            response_code = kwargs['response_code']
        except:
            response_code = True
        
        self.write_response = 0
        natempt = 0
        bstring = string+self.endOfLine
        bstring=bstring.encode()
        
        if response_code:
            while self.write_response != 8 and natempt < self.maxAttempts:
                try:
                    self.write_response=int(self.write(bstring))
                    if self.write_debug:
                        print('Input string:',string)
                        print('Output:',bstring)
                        print('write response:',self.write_response)
                except:
                    ''
                natempt+=1
            if natempt >= self.maxAttempts:
                print('Max attempt reached for psi_write.')
        else:
            self.write_response=int(self.write(bstring))
            if self.write_debug:
                print('Input string:',string)
                print('Output:',bstring)
                print('write response:',self.write_response)
        
    def psi_read(self,**kwargs):
        '''
        Function psi_read reads one byte.
        '''
        return self.read()
    
    def psi_readline(self,**kwargs):
        a = self.readline()
        return a

    def psi_write_readline(self,string,**kwargs):
        self.psi_write(string,**kwargs)
        a=self.psi_readline(**kwargs)
        if a == self.customConnectionError:
            print('Connection dropped. Restart.')
            print('------------------------------')
            self.psi_close()
            self.psi_open()
            self.psi_write_readline(string,**kwargs)
        if a == b'' and self.writeWhileEmpty:
            print('a = b"". Retry.')
            print('------------------------------')
            self.psi_close()
            self.psi_open()
            self.psi_write_readline(string,**kwargs)
        return a
        
    
    def psi_close(self,**kwargs):
        self.close()
        time.sleep(self.sleep_after_open)