"""Example of parsing command line arguments.

LICENSE AGREEMENT

The Original Code is "pyhelp.py".

The Initial Developer of the Original Code is Leica Geosystems.
Portions created by Leica Geosystems are Copyright (C) 2014 year.
Leica Geosystems. All Rights Reserved.
"""

import sys
import webbrowser
import getopt

SHORT_OPTIONS = "hv:" # v takes an argument, hence ":"
LONG_OPTIONS = ["help", "version="]
HELP_OPTIONS = ["-h", "--help"]
VERSION_OPTIONS = ["-v", "--version"]
USAGE = """
Usage: pyhelp.py [--version version] [--help] search-string"

Parameter:
   search-string   List of search terms that you wish to search.

Options:
   --version (-v)  Indicates what library you want to search in,
                   values are 2.1, 2.2, 2.3 or current.
   --help (-h)     Displays this message.

Examples:

  pyhelp.py re
  pyhelp.py getopt
  pyhelp.py -v 2.2 getopt
"""

# This dictionary will hold our user options. Start by defining the
# defaults, if the user defines something else, we will override the
# default.
OPTIONS = {"--version":"2.2",  # default to 2.2 library
           "--help":0}         # 0 no help; 1 show help 

    
def parse_command_line():
    """Returns the options dictionary and parameters. Generates
    getopt.GetoptError if it can not process the command line.
    """
    opts, params = getopt.getopt(sys.argv[1:], SHORT_OPTIONS, LONG_OPTIONS)
    # get the defaults
    options = OPTIONS.copy()

    for option, argument in opts:
        if option in HELP_OPTIONS:
            options["--help"] = 1
        if option in VERSION_OPTIONS:
            options["--version"] = argument

    return options, params

def make_url(version, searchterms):
    """Returns a URL based on the version and search terms."""
    url = "http://starship.python.net/crew/theller/pyhelp.cgi"
    url += "?keyword=" + reduce(lambda x, y: x+"+"+y, searchterms)
    url += "&version" + version
    return url

if __name__=="__main__":
    try:
        options, params = parse_command_line()
    except getopt.GetoptError, e:
        print "error: " + str(e)
        print USAGE
        sys.exit(-1)

    if options["--help"]==1:
        print USAGE
        sys.exit()

    if not params:
        print "error: search parameters required."
        sys.exit(-2)

    url = make_url(options["--version"], params)
    webbrowser.open_new(url)