import serial
import os
import time 
import random
import string

import argparse
chunksize=4096

#LOG0002   
#32 = 124 kbps
#128 = 263 kbps
#4096 = 416 kbps
#32768 = 427 kbps
#65536 = failed

serialport = serial.Serial(port='/dev/ttyACM0', baudrate=115200, timeout=1)

def establish_connection():

    serialport.write("\n".encode())
    

    serialport.write("echo off\n".encode())
    while len(serialport.readline())>0:
        continue
    

    serialport.write("test\n".encode())
    response = serialport.readline()
    hrresponse=response.rstrip().decode('ascii')
    if hrresponse != "OK":
        print("Unexpected test response:"+str(response))
        exit()

def get_filenames():

    filenames=[]

    serialport.write("ls\n".encode())
    while True:            
            response = serialport.readline()
            hrresponse=response.rstrip().decode('ascii')
            if(len(response))>0:
                #print(hrresponse)
                filenames.append(hrresponse)
                
            else:
                break

    return filenames


def get_filesize(filename):

    filesize=0

    serialport.write(("sizeof "+str(filename)+"\n").encode())
    
    response = serialport.readline()
    hrresponse=response.rstrip().decode('ascii')
    if(len(response))>0:
        filesize=int(hrresponse)
        
    return filesize


def copy_file(source,destination,expectedsize):
    os.makedirs(os.path.dirname(writefilename), exist_ok=True)

            
    transferstarttime=time.time()
    chunkstarttime=time.time()
    last_print=time.time()

    with open(writefilename, 'wb') as writer:
        serialport.write(("chunksize "+str(chunksize)+"\n").encode())
        serialport.write(("get "+filename+"\n").encode())
                    

        acc_datalen=0

        while True:
            
            '''
            response = serialport.readline()
            hrresponse=response.rstrip().decode('ascii')
            if(len(response))>0:
                #print(hrresponse)
                writer.write(response)
                
            else:
                break
            '''

            
            data=serialport.read(chunksize)
            
            if(len(data))>0: #data received
                #print("received "+str(len(data))+" bytes")
                #hrresponse=data.rstrip().decode('ascii')
                #print(hrresponse)

                acc_datalen+=len(data)

                checksum=(sum(data) & 0xFF)
                checksumarray=bytearray([checksum])

                writer.write(data)
                serialport.write(checksumarray) #request next chunk by sending checksum of last chunk        
                
            else:
                break


            if (time.time()-last_print>0.5):
                last_print=time.time()
                chunkduration=time.time()-chunkstarttime
                chunkstarttime=time.time()
                progress=acc_datalen/expectedsize
                print(str(round(progress*100,0))+"% \t"+str(round(chunkduration*1000,3))+" ms for "+str(len(data))+" Byte \t = "+str(round((len(data)/chunkduration)/1000,3))+" kB/s")


    fileduration=time.time()-transferstarttime
        
    file_stats=os.stat(writefilename)
    print("Finished transfer of "+str(acc_datalen)+" B or "+str(file_stats.st_size)+" (os) Byte in "+str(fileduration)+" s \t = "+str(round(file_stats.st_size/fileduration/1000,3))+" kB/s") 


    return acc_datalen




def log_off():
    serialport.write(("log off\n").encode())
    response = serialport.readline()
    hrresponse=response.rstrip().decode('ascii')
    if (not hrresponse.startswith("Log disabled")):
        print("Unexpected response:"+str(response))
        exit()

def delete_file(filename):       
    
    
    serialport.write(("rm "+filename+"\n").encode())
    response = serialport.readline()
    hrresponse=response.rstrip().decode('ascii')
    if hrresponse != "OK":
        print("Unexpected response:"+str(response))
        exit()



if __name__ == "__main__":


    parser = argparse.ArgumentParser(description='Transfers log files from bobbycar over serial')
    parser.add_argument('-o', '--output', nargs='?', help="output directory")
    parser.add_argument('-d','--delete', action="store_true", help="delete files after transfer")
    args = parser.parse_args()
    outputfolder="sdcard"
    if (args.output is not None):
        outputfolder = args.output
        if(outputfolder[-1]=='/'):
            outputfolder=outputfolder[:-1] #remove last slash
    print("Outputfolder:"+outputfolder)
    

    if serialport.isOpen():
        
        establish_connection()
        


        #Get File List
        filenames=get_filenames()


        #Copy all Files    
        
        failed=0
        
        for filename in filenames:
            print("Reading file "+filename)
            expectedsize=get_filesize(filename)
            print("Expecting "+str(expectedsize)+" Byte")

            writefilename=outputfolder+'/'+filename
            receivedsize=copy_file(filename,writefilename,expectedsize)
            
            if (expectedsize!=receivedsize):
                print("Warning: Filesize does not match!")
                failed+=1

            print("")

        print(str(len(filenames))+" Files copied with "+str(failed)+" failed")
        
        

        #Delete all files        
        if (args.delete):
            if (failed>0):
                print("Copy not successful. Files won't be deleted!")
                exit()
            deletecheckstring=''.join(random.choices(string.ascii_lowercase, k=3))
            deletecheck=input("Enter "+deletecheckstring+" to confirm deletion of "+str(len(filenames))+" files on bobbycar:")

            if (deletecheck==deletecheckstring):
                log_off()
                for filename in filenames:
                    print("Deleting "+filename)
                    delete_file(filename)
            else:
                print("Verification failed!")
            
        

    serialport.write("echo on\n".encode())

    serialport.close()