"""
A script to get a feed full of links (like Delicious bookmarks) and post
batches of them to a single entry on LJ. It accumulates links until there are
MAX_PENDING of them or until the last LJ entry it made was MAX_TIME ago.

The information which it needs between runs is written to PICKLE_FILE.
"""
# $Id: lj-minifeed.py,v 1.5 2009/10/07 22:41:58 paul Exp $
import xml.dom.minidom
import md5
import sys
import pickle
import feedparser
import codecs
import xmlrpclib
import pickle
import datetime
import time

PICKLE_FILE = "minifeed.data"
MAX_PENDING = 10 # post if we have this many items pending
MAX_TIME = 60 * 60 * 24 * 4 # or if we have something pending and it's been this long
POST_HEADING = "<img src='http://pw201.icons.ljtoys.org.uk/mi/dot.gif' border=0 alt=''>" # HTML at the begining of the body of the post. You'll want to change this

# Cheapo object persistence via pickle. This is the the object we 
# save and restore. The defaults are only used if we can't find the
# pickle file.
class State:
    def __init__(self):
        self.seen_guids = []
        self.feed_url = "http://feeds.delicious.com/v2/rss/pw201?count=15"
        self.etag = None
        self.modified = None
        self.pending = []
        self.last_time = 0
        self.tag_dict = {}

def update_lj_args(lj, args, username, password):
    challenge = lj.LJ.XMLRPC.getchallenge()
    std = {
            'version': 1, # so LJ assumes we're using UTF-8.
            'auth_method': 'challenge',
            'auth_challenge': challenge['challenge'],
            'auth_response': md5.new(challenge['challenge'] + md5.new(password).hexdigest()).hexdigest(),
            'username': username,
            }
    args.update(std)

def post_to_lj(body, title, tags, username, password):
    # Faff to comply with LJ's bots policy
    class CustomTransport(xmlrpclib.Transport):
        user_agent = "http://www.noctua.org.uk/paul/software/lj-minifeed.html; pw201 AT livejournal.com, running on behalf of lj user " + username
    lj = xmlrpclib.ServerProxy("http://www.livejournal.com/interface/xmlrpc", CustomTransport())
    args = {}
    update_lj_args(lj, args, username, password)
    # I don't want to create new tags on LJ for every tag I use on delicious
    # but I do want to use the LJ tags if they already existed. So we check the
    # delicious tags against the LJ ones. I use a "-" for a space on delicious,
    # spaces are allowed in tags on LJ.
    lj_tags = [t['name'] for t in lj.LJ.XMLRPC.getusertags(args)['tags']]
    munged_tags = [t.replace('-', ' ') for t in tags]
    post_tags = "link blog," + ",".join([t for t in munged_tags if t in lj_tags]) 

    now = datetime.datetime.now()
    args =  {
            "event" : body,
            "subject" : title,
            "year" : now.year,
            "mon" : now.month,
            "day" : now.day,
            "hour": now.hour,
            "min" : now.minute,
            "props": {"taglist": post_tags}
            }
    update_lj_args(lj, args, username, password)
    return lj.LJ.XMLRPC.postevent(args)


def get_html(item):
    """
    Generate HTML summary for an entry in the feed
    """
    html = u'<dt><a href="%s">%s</a>' % (item.link, item.title)
    if item.has_key("description"):
        html += '<dd>%s' % item.description
    if item.has_key("categories"):    
        html += '<br><small>(tags: %s)</small>' % " ".join(['<a href="%s%s">%s</a>' % (x[0], x[1], x[1]) for x in item.categories])
    
    return html

if __name__ == "__main__":
    try:
        p = open(PICKLE_FILE)
        state = pickle.load(p)
        p.close()
    except:
        state = State()

    # I keep my username and password in an xml file which configures my backup
    # tool. If you don't, you'll need to alter this.
    config = xml.dom.minidom.parse("ljdump.config.pw201")
    username = config.documentElement.getElementsByTagName("username")[0].childNodes[0].data
    password = config.documentElement.getElementsByTagName("password")[0].childNodes[0].data

    f = feedparser.parse(state.feed_url, etag=state.etag, modified=state.modified)
    # Be nice to the other side by remembering when we last polled them
    if f.has_key('etag'):
        state.etag = f.etag
    if f.has_key('modified'):
        state.modified = f.modified
    if f.status == 301: # Moved
        state.feed_url = f.href

    new_entries = [x for x in f.entries if x.id not in state.seen_guids]

    state.pending.extend([get_html(x) for x in new_entries])

    for e in new_entries:
        state.seen_guids.insert(0, e.id)
        if e.has_key("categories"):
            for c in e.categories:
                state.tag_dict[c[1]] = state.tag_dict.setdefault(c[1], 0) + 1
    state.seen_guids = state.seen_guids[:100] # Don't let this grow without limit

    # Is it time to post an entry to LJ?
    if state.pending and (len(state.pending) > MAX_PENDING or time.time() - state.last_time > MAX_TIME):
        body = POST_HEADING + u"<dl>" + "".join(state.pending) + "</dl>"

        # Put the most used tags in the subject of the posting
        popular_tags = state.tag_dict.keys()
        popular_tags.sort(lambda x, y: -cmp(state.tag_dict[x], state.tag_dict[y]))
        print post_to_lj(body, "Link blog: " + ", ".join(popular_tags[:4]), state.tag_dict.keys(), username, password)
        state.last_time = time.time()        
        state.pending = []
        state.tag_dict = {}

    # Remember everything
    p = open(PICKLE_FILE, "w")
    pickle.dump(state, p)
    p.close()