#!/usr/bin/env python

# Copyright (C) 2006 Julian Smith, jules@op59.net.
#
# 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.
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

'''Params:

    --dw <desktop> <window>
        Extract <user>@<machine>:<dir> from specified window's titlebar
    -c
        Open document, using new selection.
    --delay <secs>
    -s
        Open document, using existing selection if possible.
    -t <text>
    --throwbackx <executable>
        Location of the throwbackx executable.
    -v
        Verbose
'''

import os, re, sys, time

debugout = sys.stdout
#debugout = open( '/home/jules/throwback-out', 'a')

def make_command( filename, line, titlebar):
    '''
    Returns a command that will open <filename> at line number <line>,
    using info in <titlebar> to ssh to appropriate machine and cd to
    appropriate directory.

    We expect <titlebar> to be <user>@<machine>:<dir>[/<leaf>]...
    '''

    # make a command that calls nedit's client, variously called ncl,
    # neditc etc. i have a softlink in ~/bin/n on all my systems.
    command = '~/bin/n -line ' + str( line) + ' \'' + filename + '\''
    
    if titlebar:
        user_machine, directory = titlebar.split( ':', 1)
        directory = directory.split( ' ', 1)[0]
        if not directory.endswith( '/'):
            directory = os.path.dirname( directory)
        command = 'ssh -X ' + user_machine + ' "cd ' + directory + ' && ' + command + '"'
    
    return command


def parse( selection):
    '''
    parses the given X Window selection, returning (<filename>, <line>),
    both strings.
    '''
    
    m = re.match( '[^ ]+@[^ ]+ +(.*)', selection)
    if m:
        #print 'skipping prefix: ', selection
        selection = m.group(1)
        #print 'skipping prefix: ', selection
    
    # try gdb format:
    m = re.match( 'File "([^"]+)", line ([0-9]+)', selection)
    if m:
        return m.group(1), m.group(2)
    
    # gdb backtrace format:
    m = re.match( '#[0-9][^\n]+ at ([^:]+):([0-9]+)', selection)
    if m:
        return m.group(1), m.group(2)
    
    # try python format:
    m = re.match( 'Line ([0-9]+) of "([^"]+)"', selection)
    if m:
        return m.group(2), m.group(1)
    
    # gcc/grep format:
    # skip any initial `[...]':
    if selection.startswith( '['):
        i = selection.find( ']')
        if i>0:
            selection = selection[i+1:].strip()
    m = re.match( '([^:]+):([0-9]*)', selection)
    if m:
        filename = m.group(1)
        line = m.group(2)
        if line=='':    line = '1'
        return filename, line
    
    m = re.match( '([^: ]+)', selection)
    if m:
        filename = m.group(1)
        return filename, 1
    
    raise Exception( 'can\'t parse selection: ' + repr( selection))

def read_x_selection( throwbackx_exe):
    #child_in, child_outerr = os.popen4( throwbackx_exe + ' --selection')
    child_in, child_outerr = os.popen4( 'xclip -o')
    return child_outerr.read()


def main():

    verbose                 = 0
    desktop                 = None
    window                  = None
    throwbackx_exe          = None
    
    do = None
    selection = ''
    
    #print 'argv=', sys.argv
    
    args = iter( sys.argv[1:])
    while True:
        try:    arg = args.next()
        except StopIteration:   break
        if arg=='--dw':
            desktop = args.next()
            window = args.next()
        elif arg=='-c':
            do = 'c'
        elif arg=='-s':
            do = 's'
        elif arg=='-t':
            do = 't'
            selection = args.next()
        elif arg=='--throwbackx':
            throwbackx_exe = args.next()
        elif arg=='-v':
            verbose += 1
            #if verbose==1:
            #    debugout = open( '/home/jules/throwback-out', 'a')
        elif arg=='--delay':
            time.sleep( int( args.next()))
        elif arg=='-h' or arg=='--help':
            print __doc__
        else:
            raise Exception( 'unrecognised option: ' + arg)
        
        verbose = 0
        if verbose==1:
            debugout = open( '/home/jules/throwback-out', 'a')
    if do:
        if not throwbackx_exe:
            # find our directory; it should contain the throwbackx executable:
            throwback_dir = os.path.dirname( os.path.abspath( sys.argv[0]))
            throwbackx_exe = os.path.join( throwback_dir, 'throwbackx.exe')
            if not os.path.isfile( throwbackx_exe):
                raise Exception( 'can\'t find ' + throwbackx_exe + '. it should'
                        ' be built from the throwbackx.c source file - see that file'
                        ' for details.')

        if do=='s':
            # use existing selection if available:
            selection = read_x_selection( throwbackx_exe).strip()
        if selection=='':
            # fake a triple-click to select whole line under the pointer.
            os.system( throwbackx_exe + ' --click --click --click')

            selection = read_x_selection( throwbackx_exe).strip()

        if verbose:
            print >>debugout, 'selection is:', selection

        filename, line = parse( selection)

        if verbose:
            print >>debugout, 'filename:', filename
            print >>debugout, 'line:', line
        
        #if not os.path.exists( filename):
        #    raise Exception( 'fiename doesn\'t exist: ' + filename)
        
        if desktop and window:
            if verbose:
                print >>debugout, 'dw:', desktop, window
            # we have a windowID, so try to read its titlebar, and from that
            # infer the user/machine:
            child_in, child_outerr = os.popen4(
                    throwbackx_exe + ' --title '
                    + desktop + ' ' + window)
            titlebar = child_outerr.read()
        else:
            titlebar = None

        command = make_command( filename, line, titlebar)

        if verbose:
            print >>debugout, 'command is:', command

        os.system( command)

if __name__=='__main__':
    try:
        main()
    except Exception, e:
        if 0:
            print >>debugout, 'throwback:', e
            sys.exit(1)
        else:
            raise