#!/usr/bin/env python
#
# Copyright (C) 2003-2011 Upi Tamminen <desaster@dragonlight.fi>
#

import getopt
import os
import struct
import sys
import time

OP_OPEN, OP_CLOSE, OP_WRITE, OP_EXEC = 1, 2, 3, 4
TYPE_INPUT, TYPE_OUTPUT, TYPE_INTERACT = 1, 2, 3


def playlog(fd, settings):
    ssize = struct.calcsize('<iLiiLL')
    currtty, prevtime, prefdir = 0, 0, 0

    color = None

    if sys.version_info >= (3,):
        stdout = sys.stdout.buffer
    else:
        stdout = sys.stdout

    while 1:
        try:
            (op, tty, length, dir, sec, usec) = \
                struct.unpack('<iLiiLL', fd.read(ssize))
            data = fd.read(length)
        except struct.error:
            if settings['tail']:
                prevtime = 0
                time.sleep(0.1)
                settings['maxdelay'] = 0
                continue
            break

        if currtty == 0: currtty = tty

        if str(tty) == str(currtty) and op == OP_WRITE:
            # the first stream seen is considered 'output'
            if prefdir == 0:
                prefdir = dir
                # use the other direction
                if settings['input_only']:
                    prefdir = TYPE_INPUT
                    if dir == TYPE_INPUT: prefdir = TYPE_OUTPUT
            if dir == TYPE_INTERACT:
                color = '\033[36m'
            elif dir == TYPE_INPUT:
                color = '\033[33m'
            if dir == prefdir or settings['both_dirs']:
                curtime = float(sec) + float(usec) / 1000000
                if prevtime != 0:
                    sleeptime = curtime - prevtime
                    if sleeptime > settings['maxdelay']:
                        sleeptime = settings['maxdelay']
                    if settings['maxdelay'] > 0:
                        time.sleep(sleeptime)
                prevtime = curtime
                if settings['colorify'] and color:
                    stdout.write(color)
                stdout.write(data)
                if settings['colorify'] and color:
                    stdout.write('\033[0m')
                    color = None
                sys.stdout.flush()
        elif str(tty) == str(currtty) and op == OP_CLOSE:
            break


def help(brief=0):
    print('Usage: %s [-bfhi] [-m secs] [-w file] <tty-log-file> <tty-log-file>...\n' % \
          os.path.basename(sys.argv[0]))

    if not brief:
        print('  -f             keep trying to read the log until it\'s closed')
        print('  -m <seconds>   maximum delay in seconds, to avoid' + \
              ' boredom or fast-forward\n' + \
              '                 to the end. (default is 3.0)')
        print('  -i             show the input stream instead of output')
        print('  -b             show both input and output streams')
        print('  -c             colorify the output stream based on what streams are being received')
        print('  -h             display this help\n')

    sys.exit(1)


if __name__ == '__main__':

    settings = {
        'tail': 0,
        'maxdelay': 3.0,
        'input_only': 0,
        'both_dirs': 0,
        'colorify': 0,
    }

    try:
        optlist, args = getopt.getopt(sys.argv[1:], 'fhibcm:w:', ['help'])
    except getopt.GetoptError as error:
        print('Error: %s\n' % error)
        help()

    for o, a in optlist:
        if o == '-f':
            settings['tail'] = 1
        elif o == '-m':
            settings['maxdelay'] = float(a)  # takes decimals
        elif o == '-i':
            settings['input_only'] = 1
        elif o == '-b':
            settings['both_dirs'] = 1
        elif o in ['-h', '--help']:
            help()
        elif o == '-c':
            settings['colorify'] = 1

    if len(args) < 1:
        help()

    try:
        for logfile in args:
            logfd = open(logfile, 'rb')
            playlog(logfd, settings)
    except IOError:
        print("\n\n[!] Couldn't open log file (%s)!" % logfile)
        sys.exit(2)