#!/usr/bin/env python

import getopt
import sys

def usage():
    print '''Print side-by-side diff in HTML output.
Usage:
    pdiff.py [-F] [-C lines] [-W columnwidth] file1 file2
        -C: the number of context lines shown (default is 5)
        -F: show the full files
        -W: the number of maximum characters in column'''
    sys.exit(-1)

def main():
    context = True
    numlines = 5
    wrapcolumn = 40
    # Handle command-line arguments
    try:
        optlist, args = getopt.getopt(sys.argv[1:], 'C:FW:')
    except getopt.GetoptError, strerror:
        print 'Error:', strerror
        usage()
    for (key,value) in optlist:
        if key == '-F':
            context = False
            numlines = 0
        elif key == '-C':
            numlines = int(value)
        elif key == '-W':
            wrapcolumn = int(value)
    if len(args) != 2:
        print 'Error: specify two files to compare'
        usage()
    filename1, filename2 = args
        
    # Main process
    try:
        import difflib
        htmlDiff = difflib.HtmlDiff(wrapcolumn=wrapcolumn)
    except (ImportError, AttributeError):
        print 'Error: cannot load difflib.HtmlDiff. You need Python 2.4 or later.'
        sys.exit(-1)
    try:
        fromlines = open(filename1).readlines()
        tolines = open(filename2).readlines()
    except IOError, strerror:
        print strerror
        sys.exit(2)
    diff_html = htmlDiff.make_file(fromlines=fromlines, tolines=tolines,
                                   fromdesc=filename1, todesc=filename2,
                                   context=context, numlines=numlines)
    print diff_html

if __name__ == "__main__":
    main()