###############################################################################
# Object: Interface to FlexStack Camera demo
# Author: antics( christopher pepe )
#
# Descritpion: Host side application that uploads a jpg image from the
#           flexstack demo.  BMP is scattered thru this file because it 
#           was built from another host app that worked with bitmaps.
#
#           This application is intended to run on a host with bluetooth
#           and connect to the FlexStack via the RFCOMM profile for the demo.
#           In practice it would be useful with any RS232 to radio converter,
#           ideally radios with some real range like a few miles.  
#
#           Use this front end to issue a command to the embedded system and
#           upload the resultant image if needed.  This program is fairly 
#           customized for the demo its used in and should be modified to be
#           more generic or easier to setup.
###############################################################################

import os
import sys
import serial
import getopt
from time import time

def binDummy(fname):
    """
    This function revert the CRLF (carriage return, line feed)
    characters to '0x0a'.  Because the embedded system simply
    prints the binary data to a terminal the '0x0a' characters 
    are automatically translated to '0x0d0a'.  This function 
    undoes that.
    """
    fout=open(fname,'wb')
    fd=open('dummy','rb')
    byte = fd.read(1)
    while byte != '':
        next = fd.read(1)
        if byte == '\x0d' and next == '\x0a':
            byte = next
            next = fd.read(1)
        fout.write(byte)
        byte = next
    fd.close()
    fout.close()


CHUNKSIZE = 2048

#default serial device, file name, and command
SERDEV = '/dev/ttyUSB0'
BMPFILE = 'dummy'
CMD = 'TN'

#override defaults with commandline options
#pyHostController.py -c <command> -d /dev/tty<tty device> -f <filename.jpg>
opts,args = getopt.getopt(sys.argv[1:] , 'f:d:c:z' )
opts = dict(opts)   

cmd = opts.get('-c', CMD)
serdev = opts.get('-d', SERDEV)
bmpfile = opts.get('-f', BMPFILE)

#open the serial device
ser = serial.Serial(serdev, 57600, timeout=2, rtscts=0, xonxoff=0,
                     parity=serial.PARITY_NONE)
if ser.isOpen():
   #print 'Serial port ' + str(ser.portstr) + ' is open'
   fake=1
else:
   print 'Serial port ' + str(ser.portstr) + " can't be opened"

if 1: #FIXME: assuming connection is up, (isUp != '':)
    startTime = time()
    bmpparts = []
    cnkCnt = 1
    #Send command to FlexStack
    ser.write(cmd + "\r\n")
    #$ is the start char, read
    # the serial port until $
    # is recieved.
    fReady = ser.read(1)
    if fReady != '$':
        fReady = ser.read(1)
    #Grab the header which is no more
    # than 100 chars long.
    header = ser.read(100)
    hList = header.split(':')
    try:
        filename = hList[0].split('$')[1]
    except:
        filename = hList[0]
    filesize = hList[1]
    #chunk0 is the leftover binary data
    #once the filename and filesize have
    #been stripped out
    chunk0 = hList[2]
    #Write chunk0 to file for debugging
    #debug = file('debug.txt', 'wb')
    #debug.write(chunk0)
    #debug.close()
    
    #print 'Filename: ' + filename
    #print 'Filesize: ' + filesize
    chunk = ser.read(CHUNKSIZE)
    while len(chunk) == CHUNKSIZE:
        bmpparts.append(chunk)
        chunk = ser.read(2048)
        #print 'Reading Chunk ' + str(cnkCnt) + ' [' + str(CHUNKSIZE) + ' bytes]'
        cnkCnt += 1
    #There are some extra chars at the end of the 
    #stream because the embedded shell gets confused.
    #Time constraints dictated it being fixed here since
    #the extra output is always the same.
    #rm '\r\nACK\r\ncmd>cmd>'
    bmpparts.append(chunk[:-12])

    ###use filename to write temp file which contains
    ###extra characters
    fd = file(bmpfile,'wb')
    #fd.write(bmp)
    fd.write(chunk0)
    for chunk in bmpparts:
        fd.write(chunk)
    fd.close()
    ###use eval('0xff') to get int.  how to get that to '\xff'?
    #print "Capture took " + str(time()-startTime) + " sec"
    #print 'Wrote BMP to ' + str(os.path.abspath(os.curdir)) + str(bmpfile)
    
    ser.close()
    if( filename[:2] == 'tn'):
        binDummy('../images/tn/' + filename)
    else:
        binDummy('../images/' + filename)
else:
    print 'Serial device is not responding'
ser.close()