#!/usr/bin/env python2.5
"""
Filename:      google_correct.py
Purpose:       correct a keyword using google search
Authors:       (c) Michael Prokop <mika@grml.org>
Bug-Reports:   see http://grml.org/bugs/
License:       This file is licensed under the GPL v2 or any later version.
Latest change: Sun Mar 09 19:19:04 CET 2008 [mika]

Notice:

* requires xsel binary
* requires python >= 2.4 (for urllib2), version 2.5 suggested :)
* if python-notify is installed it's used as notification system

History:

* 2008-03-09: improve cmdline parsing logic [gregor herrmann]
              include support for libnotify [mika]
              usage information for -h/--help [mika]
              provide output on stdout even when using xsel [mika]
* 2008-02-11: initial version [mika]

Whishlist:

* support multiple keywords in one single invocation
* use python-xlib instead of xsel,
  like in http://kalvdans.no-ip.org/svn/saturnapps/selection.py ?
* support something like a search gateway for anonymous search requests
* support different backends (like fuzzy search in local dictionaries)
* provide small selection menu for X, vim,...
"""

import os
import re
import urllib
import urllib2
import subprocess
import sys

_correction_re = re.compile(r'<font[^>]*>Did you mean: </font><a[^>]*>'
                            r'<b><i>(.*?)</i></b></a>(?i)')

def usage():
    print """
google_correct.py: correct a keyword using google's 'Did you mean' feature

Usage:

      Either run:

        google_correct.py <keyword>

      or select keyword in X and execute the script to set new X selection:

        google_correct.py

Send bug reports, feature requests and patches to Michael Prokop <mika@grml.org>
"""

def which(filename):
    """Check whether a given program can be executed"""
    for path in (os.environ.get('PATH') or os.defpath).split(os.pathsep):
        myfile = os.path.join(path, filename)
        if os.access(myfile, os.X_OK):
            return myfile

def correct_keyword(keyword):
    """Correct spelling of a keyword using google's 'Did you mean' feature"""
    req = urllib2.Request('http://www.google.com/search?%s' % urllib.urlencode({
        'q':        keyword.encode('utf-8'),
        'spell':    '1'
    }))
    req.add_header('User-Agent', 'Mikas-Keyword-Corrector/1.0 :-)')
    resp = urllib2.urlopen(req)
    match = _correction_re.search(resp.read())
    return match and match.group(1) or keyword

# would be nice to support multiple keywords at once,
# needs work in _correction_re though:
#def cmdline():
#    for argument in sys.argv[1:]:
#        return ' '.join(arg for arg in sys.argv[1:])
#keyword = cmdline()

def get_x_selection():
    """Get X selection"""
    proc = subprocess.Popen(['xsel', ], stdout=subprocess.PIPE)
    x_selection = proc.stdout.read()
    proc.stdout.close()
    proc.wait()
    return x_selection

def set_x_selection(keyword):
    """Set X selection to the given keyword"""
    proc = subprocess.Popen(['xsel', '-i'], stdin=subprocess.PIPE)
    proc.stdin.write(keyword)
    proc.stdin.close()
    proc.wait()

def default_cb(n, action):
    assert action == "default"
    print "You clicked the default action"
    n.close()
    gtk.main_quit()

def notify(new_keyword, old_keyword):
    try:
        import pynotify
        if pynotify.init("google_correct"):
            if new_keyword is not old_keyword:
                n = pynotify.Notification("New keyword for \"%s\":" % old_keyword, new_keyword)
            else:
                n = pynotify.Notification("google_correct result:", "No new keyword for \"%s\" found" % old_keyword)

            n.set_timeout(2000)
            n.show()
    except:
        return 0 # don't print anything because someone might use the output :)

if __name__ == '__main__':
    if '--help' in sys.argv or '-h' in sys.argv:
        usage()
        sys.exit(1);

    if sys.argv[1:]:
        # print it to stdout:
        old_keyword = sys.argv[1]
        new_keyword = correct_keyword(old_keyword)
        print new_keyword
        notify(new_keyword, old_keyword)
        # or if you prefer to put it directly to X selection:
        #set_x_selection(correct_keyword(sys.argv[1]))
    else:
       if which('xsel'):
           old_keyword = get_x_selection()
           new_keyword = correct_keyword(old_keyword)
           print new_keyword
           set_x_selection(new_keyword)
           notify(new_keyword, old_keyword)
       else:
           sys.exit("Sorry, xsel not found. Exiting.")

## END OF FILE #################################################################
# vim: ft=python tw=100 ai et