#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# a at foo dot be - Alexandre Dulaunoy - http://www.foo.be/cgi-bin/wiki.pl/RssAny
#
# rsscluster.py is a simple script to cluster items from an rss feed based on a
#               time interval (expressed in number of days). The maxitem is the
#               number of item maximum after the clustering.
#
# an example use is for Mastodon where you can have a lot of toots during
# one day and you want to cluster them in one single item in RSS or in (X)HTML.
#
# example of use :
#  python3 rsscluster.py --interval 5 --maxitem 20 "https://paperbay.org/@a.rss" >adulau.xml

import feedparser
import sys, os
import time
import datetime
import xml.etree.ElementTree as ET
import hashlib
from optparse import OptionParser

# print sys.stdout.encoding
version = "0.2"

feedparser.USER_AGENT = "rsscluster.py " + version + " +https://github.com/adulau/rss-tools"


def date_as_rfc(value):
    return time.strftime("%a, %d %b %Y %H:%M:%S +0000", time.localtime(value))


def build_rss(myitem, maxitem):

    RSSroot = ET.Element("rss", {"version": "2.0"})
    RSSchannel = ET.SubElement(RSSroot, "channel")

    ET.SubElement(RSSchannel, "title").text = (
        "RSS cluster of " + str(url) + " per " + str(options.interval) + " days"
    )
    ET.SubElement(RSSchannel, "link").text = str(url)
    ET.SubElement(RSSchannel, "description").text = (
        "RSS cluster of " + str(url) + " per " + str(options.interval) + " days"
    )
    ET.SubElement(RSSchannel, "generator").text = "by rsscluster.py " + version
    ET.SubElement(RSSchannel, "pubDate").text = date_as_rfc(time.time())

    for bloodyitem in myitem[0:maxitem]:

        RSSitem = ET.SubElement(RSSchannel, "item")
        ET.SubElement(RSSitem, "title").text = (
            "clustered data of "
            + date_as_rfc(float(bloodyitem[0]))
            + " for "
            + str(url)
        )
        ET.SubElement(RSSitem, "pubDate").text = date_as_rfc(float(bloodyitem[0]))
        ET.SubElement(RSSitem, "description").text = bloodyitem[1]
        h = hashlib.md5()
        h.update(bloodyitem[1].encode("utf-8"))
        ET.SubElement(RSSitem, "guid").text = h.hexdigest()

    RSSfeed = ET.ElementTree(RSSroot)
    feed = ET.tostring(RSSroot)
    return feed


def complete_feed(myfeed):

    myheader = '<?xml version="1.0"?>'
    return myheader + str(myfeed)


def DaysInSec(val):

    return int(val) * 24 * 60 * 60


usage = "usage: %prog [options] url"
parser = OptionParser(usage)

parser.add_option(
    "-m",
    "--maxitem",
    dest="maxitem",
    help="maximum item to list in the feed, default 200",
)
parser.add_option(
    "-i",
    "--interval",
    dest="interval",
    help="time interval expressed in days, default 1 day",
)

# 2007-11-10 11:25:51
pattern = "%Y-%m-%d %H:%M:%S"

(options, args) = parser.parse_args()

if options.interval is None:
    options.interval = 1
    options.output = 1

if options.maxitem == None:
    options.maxitem = 200


if len(args) != 1:
    parser.print_help()
    parser.error("incorrect number of arguments")

allitem = {}
url = args[0]

d = feedparser.parse(url)

if options.interval is None:
    options.interval = 0

interval = DaysInSec(options.interval)

previousepoch = []
clusteredepoch = []
tcluster = []

for el in d.entries:
    if 'modified_parsed' in el:
        eldatetime = datetime.datetime.fromtimestamp(time.mktime(el.modified_parsed))
    else:
        eldatetime = datetime.datetime.fromtimestamp(time.mktime(el.published_parsed))

    elepoch = int(time.mktime(time.strptime(str(eldatetime), pattern)))

    if len(previousepoch):

        # print el.link, int(previousepoch[0])-int(elepoch), interval

        if len(clusteredepoch):
            value = clusteredepoch.pop()
        else:
            value = ""
        if 'title' in el:
            clusteredepoch.append(value + ' <a href="' + el.link + '">' + el.title + "</a>")
        else:
            clusteredepoch.append(value + ' <a href="' + el.link + '">' + el.summary + "</a>")

        if not ((int(previousepoch[0]) - int(elepoch)) < interval):

            value = clusteredepoch.pop()

            starttimetuple = datetime.datetime.fromtimestamp(previousepoch[0])
            endttimetuple = datetime.datetime.fromtimestamp(previousepoch.pop())
            clusteredepoch.append(
                value
                + " from: "
                + str(starttimetuple.ctime())
                + " to: "
                + str(endttimetuple.ctime())
            )
            if previousepoch:
                startdatelist = str(previousepoch[0]), str(
                    clusteredepoch[len(clusteredepoch) - 1]
                )
                tcluster.append(startdatelist)
                del previousepoch[0 : len(previousepoch)]
                del clusteredepoch[0 : len(clusteredepoch)]
    else:
        if 'title' in el:
            clusteredepoch.append(' <a href="' + el.link + '">' + el.title + "</a>")
        else:
            clusteredepoch.append(' <a href="' + el.link + '">' + el.summary + "</a>")

    previousepoch.append(elepoch)

# if last cluster list was not complete, we add the time period information.
if len(previousepoch):
    value = clusteredepoch.pop()
    starttimetuple = datetime.datetime.fromtimestamp(previousepoch[0])
    endttimetuple = datetime.datetime.fromtimestamp(previousepoch.pop())
    clusteredepoch.append(
        value
        + " from: "
        + str(starttimetuple.ctime())
        + " to: "
        + str(endttimetuple.ctime())
    )
    del previousepoch[0 : len(previousepoch)]


tcluster.sort()
tcluster.reverse()
print(complete_feed(build_rss(tcluster, int(options.maxitem))))