#!/usr/bin/python
# vim:fileencoding=utf8
# Both python and vim understand the above encoding declaration

#<!--Exclude from bashfeed-->

"""
 Control program for the Home Electronics Tira-2 IR transceiver
 Copyright © 2006,2007 Lincor Solutions.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 2 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.
"""

# 1.0, 28 Apr 2006, Initial release
# 1.1, 02 May 2006, Support delays in transmit list
# 1.2, 03 May 2006, Handle Tira-2 responses (to transmit command)
#                   with interspersed 6 bytes data
# 1.3, 03 May 2006, Retry button capture if remote too close to Tira-2
# 1.4, 29 Mar 2007, Retry button capture if get "remote code too complex"
#                   as this was reported as being a transient error.
#                   Don't prompt for button name again on transient errors.
#                   Don't write a new config file if nothing was changed.
#                   Check config file before checking Tira-2 communications.
# 1.5, 16 Jul 2007, Increase time to wait for data to finish arriving
#                   from 200ms to 340ms, as this was seen to be needed with the
#                   Tira-2.4 (compared to the Tira-2.1 as originally tested).
#                   Display a hexdump of received data when --verbose specified,
#                   to aid debugging, and to help show erroneous repeats
#                   (holding the remote button too long), to the user.
#                   Warn user about the possibility of holding the remote button
#                   too long, when invalid data is received.
# 1.6, 12 Aug 2008, Support from Jake Luck <tira@10k.org> for older Tira 1.x
# 1.7, 16 Sep 2009, Add a --find option to report where devices are connected.

# Notes:
#   Has only been tested on linux at present (with python 2.3 - 2.6).
#
#   This script takes around 0.1s to be parsed (and transmit a single code),
#   with python 2.4.1 on a 1.7GHz pentium-m.
#   One could py_compile.compile() it to save another 0.065s.
#   Update: Python 2.5 startup is much faster and only takes 0.055s
#   to parse this script and transmit a single code
#   (without waiting for confirmation from the Tira-2).
#
#   Details of the Tira-2 protocol implemented here, are at:
#   http://www.home-electro.com/download/Protocol2.pdf

# TODO:
#   Implement locking for the serial port
#   Support serial versions of device as well as USB
#   Maybe support repeats (*num) in transmit list?

##################################################################

import sys,os,time,tty

def get_options():

    global verbose,configs,remote,port,transmit,capture,find

    verbose=False
    configs="."
    remote=None
    port="/dev/ttyUSB0"
    transmit=None
    capture=False
    find=False

    def Usage():
        print "Usage: %s OPTIONS" % os.path.split(sys.argv[0])[1]
        print
        print "    [--help]"
        print "    [--verbose]"
        print
        print "    --remote=remote_name"
        print
        print "    --capture"
        print "        or"
        print "    --transmit=button_name[:delay_in_ms][,button_name,...]"
        print "        or"
        print "    --find"
        print
        print "    [--port=%s]" % port
        print "    [--configs=%s]" % configs

    import getopt
    try:
        lOpts, lArgs = getopt.getopt(sys.argv[1:], "",
        ["help","verbose","port=","capture","transmit=",
         "find", "remote=","configs="])

        if ("--help","") in lOpts:
            Usage()
            sys.exit(None)

        for opt in lOpts:
            if opt[0] == "--verbose":
                verbose=True
            elif opt[0] == "--port":
                port=opt[1]
            elif opt[0] == "--capture":
                capture=True
            elif opt[0] == "--transmit":
                transmit=opt[1]
            elif opt[0] == "--find":
                find=True
            elif opt[0] == "--remote":
                remote=opt[1]
            elif opt[0] == "--configs":
                configs=opt[1]
                if configs[-1]=='/':
                    configs=configs[:-1]

        if (not capture and not transmit and not find) or \
           (capture+(transmit!=None)+find > 1) or \
           (not remote and (transmit!=None or capture)):
            Usage()
            sys.exit(1)

    except getopt.error, msg:
        print msg
        print
        Usage()
        sys.exit(2)

def handle_ctrl_c():
    def cli_exception(type, value, tb):
        if not issubclass(type, KeyboardInterrupt):
            sys.__excepthook__(type, value, tb)
    if sys.stdin.isatty():
        sys.excepthook=cli_exception

#http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/142812
FILTER=''.join([(len(repr(chr(x)))==3) and chr(x) or '.' for x in range(256)])
def hexdump(src, length=16):
    result=[]
    for i in xrange(0, len(src), length):
       s = src[i:i+length]
       hexa = ' '.join(["%02X"%ord(x) for x in s])
       printable = s.translate(FILTER)
       result.append("%04X   %-*s   %s\n" % (i, length*3, hexa, printable))
    return ''.join(result)

def read_chunk(fd,num=0,timeout=0.5):
    """
    num =     number of bytes to wait for.      0 = don't care
    timeout = time in seconds to wait for data. 0 = don't care
    """
    check_delay=20 #ms. Wait this long between data polls. TODO: Use VTIME
    wait_delay=340 #ms. Wait this long for data to finish (if num not specified)
    ret = ""
    num_left=num
    wait=0
    start = time.time()
    while (not timeout) or (time.time()-start < timeout):
        try:
            ret += os.read(fd, num_left or 256)
            if num:
                if len(ret) == num: break
                num_left=num-len(ret)
        except OSError, e:
            if e.errno == 11:
                if len(ret):
                    wait+=1
                    if wait > (wait_delay/check_delay): break
        time.sleep(check_delay/1000.0)
    if verbose and len(ret):
        print "------- rxdata -------"
        print hexdump(ret),
        print "----------------------"
    return ret

def dump_txdata(txdata,c=False,name="txdata"):
    if c:
        print "unsigned char %s[]={" % name
    else:
        name_width = len(name)+2
        dash_width = (23 - name_width) / 2
        print "-"*dash_width + " " + name + " " + "-"*dash_width
    if c:
        format="0x%02X,"
    else:
        format="%02X"
    print " ".join([ format % ord(x) for x in txdata[:4]])
    for i in (0,1,2):
        for j in range(4+(i*8),4+((i+1)*8),2):
            print (format*2) % (ord(txdata[j]),ord(txdata[j+1])),
        print
    i=0
    for x in txdata[28:]:
        print format % ord(x),
        i+=1
        if i%8==0: print
    print
    if c:
        print "};"
    else:
        print "-"*23

def read_response(search_str):
    """When the Tira-2 is in "6 bytes" mode (it's default state)
       it will send a 6 byte representation of any received IR code it receives.
       Since this can happen around our response we need to
       search for our response in the noise"""
    TX_OK=False
    response=""
    retry=0
    while retry < 2:
        if retry:
            read_size=0 #subsequent reads need to read everything
        else:
            read_size=len(search_str) #shortcut the common case
        response += read_chunk(tira,num=read_size)
        if response.find(search_str) != -1:
            TX_OK=True
            break
        retry+=1
    #if retry and verbose:
    #    print hexdump(response),
    return TX_OK

def transmit_tira2(txdata):
    if not transmit: #For speed, assume not in timing mode if just transmitting
        os.write(tira,"IR") #Can't transmit in timing mode
        if read_chunk(tira,2) != "OK":
            print "Error changing to sixbytes mode"
            sys.exit(1)
    tty.tcflush(tira,tty.TCIFLUSH) #bin any pending data
    os.write(tira,txdata)
    #if transmit: return True #A dangerous optimization
    return read_response("OIX")

# ripped from pyserial. This is linux specific,
# see pyserial for OS X support.
# Hmm can do this externally to match what kernel sets for USB like:
# sudo setserial /dev/ttyS0 spd_cust baud_base "24000000"\
#                          divisor "240" closing_wait "0"\
#                          close_delay "0" low_latency
def set_custom_baudrate(fd, baudrate):
    import fcntl, termios
    import array
    buf = array.array('i', [0] * 32)

    # get serial_struct
    fcntl.ioctl(fd, termios.TIOCGSERIAL, buf)
    print buf

    # set custom divisor and baud_base
    buf[6] = 240
    buf[7] = 240 * 100000 #need root access to change this

    # update flags
    ASYNC_SPD_MASK = 0x1030
    ASYNC_SPD_CUST = 0x0030
    buf[4] &= ~ASYNC_SPD_MASK
    buf[4] |= ASYNC_SPD_CUST

    # set serial_struct
    try:
        res = fcntl.ioctl(fd, termios.TIOCSSERIAL, buf)
    except IOError:
        raise ValueError('Failed to set custom baud rate: %r' % baudrate)

def open_tira2():
    tira = os.open(port,os.O_RDWR|os.O_NONBLOCK|os.O_NOCTTY)
    tty.setraw(tira,tty.TCSAFLUSH)
    mode = tty.tcgetattr(tira)
    mode[tty.CFLAG] &= ~tty.CSTOPB #NB: 1 stop bit
    mode[tty.CFLAG] |= tty.CLOCAL  #Don't worry about DCD
    mode[tty.CFLAG] |= tty.CREAD   #Enable the receiver
    #Note baud & flow control are automatically setup (and fixed) by the linux
    #ftdi_sio module, i.e. this is redundant on the USB versions of the device
    mode[tty.CFLAG] |= tty.CRTSCTS
    mode[tty.ISPEED] = mode[tty.OSPEED] = tty.B38400 #select custom
    tty.tcsetattr(tira,tty.TCSAFLUSH,mode)
    #Note the following doesn't get the serial versions of
    #the device working, so just ignore for now
    #  set_custom_baudrate(tira, 100000)
    #Note Receiver enabled so can now receive erroneous (pending) data
    #(for example if user is holding a remote button we will get "6 bytes" info)
    #The flushes above are done too early to ignore this.
    if not transmit: #Be more robust as speed not an issue
        os.write(tira,"IV")
        version = read_chunk(tira)
        if "Tira-2." not in version and "1.1" not in version:
            return 0
    return tira

def capture_tira2(button):
    while 1:
        os.write(tira,"IC\x00\x00")
        if not read_response("OIC"):
            print "Error entering timing mode"
            sys.exit(1)
        print "Hit '%s' remote button now" % button
        timing_data = read_chunk(tira,timeout=0)
        if timing_data[-1]=="\xB2" and timing_data[-4:-2]=="\x00\x00":
            print "Valid IR code captured"
            clock = ord(timing_data[-2])
            timing_data = timing_data[:-4]
            timings=[]
            for i in range(0,len(timing_data),2):
                timings.append((ord(timing_data[i]),ord(timing_data[i+1])))
            break
        else:
            print "Invalid IR code received."
            print "Try moving the remote to around 5cm from the Tira-2, and"
            print "ensure you are not holding the button too long."

    class counter:
        def __init__(self):
            self.dict = {}
        def add(self,item):
            count = self.dict.get(item,0)
            self.dict[item] = count + 1
        def counts(self,descending=False):
            """Returns list of keys, sorted by values."""
            result = zip(self.dict.values(),self.dict.keys())
            result.sort()
            if descending: result.reverse()
            return result

    def replace_timings(old,new):
        for i in range(len(timings)):
            hi,lo = timings[i]
            if hi*256+lo == old:
                timings[i]=(new/256, new%256)

    merge_width=clock/16 #within a pulse period
    widths=counter()
    for hi,lo in timings:
        width = hi*256+lo
        widths.add(width)
    counts = widths.counts(descending=True)

    def merge(counts):
        for freq, val in counts:
            for freq2, val2 in counts:
                if (freq,val) == (freq2,val2): continue
                if val2 in range(val-merge_width,val+merge_width+1):
                    replace_timings(val2,val)
                    counts.remove((freq2,val2))
                    counts[counts.index((freq,val))]=(freq+freq2,val)
                    return True
        return False

    while merge(counts): pass

    if len(counts) > 12:
        print "Error: The remote code was too complex!"
        return None

    counts.sort()
    counts.reverse()
    counts+=[(0,0)]*(12-len(counts))
    counts = [ val for freq,val in counts ]

    txdata = "IX"+chr(clock)+chr(0x00)
    for val in counts:
        txdata += chr(val/256)
        txdata += chr(val%256)
    iter=0
    byte=0
    for hi,lo in timings:
        index = counts.index(hi*256+lo)
        if iter%2 == 0:
            byte = index<<4
        else:
            txdata += chr(byte+index)
        iter+=1
    else:
        if iter%2 == 0:
            txdata += chr(0xFF)
        else:
            txdata += chr(byte+0xF)

    if verbose: dump_txdata(txdata)

    #Retransmit so that the Tira-2 can verify things
    if transmit_tira2(txdata):
        print "The Tira-2 successfully retransmitted the captured code"
        return txdata
    else:
        print "Warning the Tira-2 did not retransmit the captured code"
        return None

##################################################################

handle_ctrl_c()

get_options()

if find:
    import glob
    ports = glob.glob("/dev/ttyUSB*")[::-1] + glob.glob("/dev/ttyS*")[::-1]
    for port in ports:
        try:
            if verbose:
                print "trying", port
            tira = open_tira2()
            if tira:
                print port
                sys.exit(0)
        except (tty.error, OSError):
            pass
    sys.exit(1)

config_filename = "%s/%s.tira2" % (configs,remote)
if os.path.isfile(config_filename):
    config = eval(open(config_filename).read())
else:
    config={}
    if transmit:
        print "Error: %s does not exist" % config_filename
        sys.exit(1)

tira = open_tira2()
if tira:
    if verbose: print "Found Tira-2"
else:
    print "Error communicating with Tira-2"
    sys.exit(1)

if transmit:
    delay=0
    for button in transmit.split(','):
        if delay: #from previous button
            time.sleep(delay/1000.0)
        if ':' in button:
            button,delay=button.split(':')
            delay=int(delay)
        else:
            delay=0
        if not config.has_key(button):
            print "Error: missing definition for %s" % repr(button)
            sys.exit(1)
        else:
            if verbose: dump_txdata(config[button],button)
            if transmit_tira2(config[button]):
                if verbose: print "Successfully transmitted %s" % repr(button)
            else:
                print "Error transmitting %s" % repr(button)
                sys.exit(1)
else:
    def get_button_name():
        button = raw_input("Enter button name (blank to end): ")
        for char in button:
            if char in "\"' ,:*": #some restrictions to future proof
                print "Sorry the %s character is not allowed" % repr(char)
                button=None
                break
        return button

    newdata=False
    while 1:
        button = get_button_name()
        if button==None: continue #invalid char
        if button=="":   break    #user finished

        txdata=None
        while not txdata: #loop over transient errors
            txdata = capture_tira2(button)
        olddata=config.get(button)
        if olddata != txdata:
            config[button]=txdata
            newdata=True
    if not newdata:
        sys.exit(0)

    config_text="# vim:nowrap syntax=python\n{\n"
    buttons=config.keys()
    buttons.sort()
    for button in buttons:
        spacing=" " * (16-(len(repr(button))+1))
        config_text += "%s:%s%s,\n" % (repr(button),spacing,
                                       repr(config[button]))
    config_text+="}\n"
    open(config_filename, 'w').write(config_text)
    print "Sucessfully updated %s" % config_filename