#!/usr/bin/env python

""" FYP page checker
nosmo@netsoc.tcd.ie
"""

import urllib
import os

def WriteRSS():
    rss = open("fypfeed.rss","w")
    
    from time import strftime, gmtime, time
    date = "%s GMT" % strftime("%a, %d %b %Y %H:%M:%S", gmtime(time()))
    
    rss.write( """<?xml version=\"1.0\"?>
    <rss version=\"2.0\">
    <channel>
    <title>CS FYP alerter</title>
    <link>http://www.netsoc.tcd.ie/~nosmo</link>
    <description>Find out about new FYPs!</description>
    <language>en-us</language>
    <pubDate>%s</pubDate>
    <lastBuildDate>%s</lastBuildDate>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <generator>Nosmo's deadly script thing</generator>
    <managingEditor>nosmo@netsoc.tcd.ie</managingEditor>
    <webMaster>nosmo@netsoc.tcd.ie</webMaster>
    <ttl>5</ttl>
    """ % (date, date))

    rss.write( """ <item>
    <title>FYP update!</title>
    <link>https://www.cs.tcd.ie/courses/ss-projects/</link>
    <description>FYP page has changed!</description>
    <pubDate>%s</pubDate>
    <guid>https://www.cs.tcd.ie/courses/ss-projects/</guid>
    </item>
    """ % date)

    rss.write( """  </channel>
    </rss>\n""")

def CheckSite():
    fypsite = urllib.urlopen("https://www.cs.tcd.ie/courses/ss-projects/")
    return fypsite.read()

def DiffwithOld(current):
    old = None
    if os.path.isfile("oldsite.html"):
        old = open("oldsite.html", "rw")
    else:
        print "Old archive didn't exist!"
        old = open("oldsite.html", "w")
        old.write(current)
        WriteRSS()
        return False

    oldinfo = old.read()

    result = oldinfo != current
    
    if result:
        print "Updated feed!"

        newpage = open("newpage.html", "w")
        newpage.write(current)
        newpage.close()
        
        WriteRSS()
        old.close()
        old = open("oldsite.html", "w")
        old.write(current)
        return True
    else:
        return False

def main():
    current = CheckSite()
    if current:
        DiffwithOld(current)
    else:
        print "Oh shit!"

if __name__ == "__main__":
    main()