#!/usr/bin/python -OO
# Copyright 2008-2012 The SABnzbd-Team <team@sabnzbd.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

"""
sabnzbd.rss - rss client functionality
"""

import re
import logging
import time
import threading
import urllib
import os

import sabnzbd
from sabnzbd.constants import *
from sabnzbd.decorators import synchronized
import sabnzbd.config as config
import sabnzbd.cfg as cfg
from sabnzbd.misc import cat_convert, sanitize_foldername, wildcard_to_re, cat_to_opts
import sabnzbd.emailer as emailer
from sabnzbd.encoding import latin1, unicoder, xml_name

import sabnzbd.utils.feedparser as feedparser

__RSS = None  # Global pointer to RSS-scanner instance


################################################################################
# Wrapper functions                                                            #
################################################################################

def init():
    global __RSS
    __RSS = RSSQueue()

def stop():
    global __RSS
    if __RSS:
        __RSS.stop()
        try:
            __RSS.join()
        except:
            pass

def del_feed(feed):
    global __RSS
    if __RSS: __RSS.delete(feed)

def run_feed(feed, download, ignoreFirst=False, force=False, readout=True):
    global __RSS
    if __RSS: return __RSS.run_feed(feed, download, ignoreFirst, force=force, readout=readout)

def show_result(feed):
    global __RSS
    if __RSS: return __RSS.show_result(feed)

def flag_downloaded(feed, id):
    global __RSS
    if __RSS: __RSS.flag_downloaded(feed, id)

def lookup_url(feed, id):
    global __RSS
    if __RSS: return __RSS.lookup_url(feed, id)

def run_method():
    global __RSS
    if __RSS:
        return __RSS.run()
    else:
        return None

def save():
    global __RSS
    if __RSS: __RSS.save()

def clear_feed(feed):
    global __RSS
    if __RSS: __RSS.clear_feed(feed)

def clear_downloaded(feed):
    global __RSS
    if __RSS: __RSS.clear_downloaded(feed)


################################################################################

def notdefault(item):
    """ Return True if not 'Default'/'*'/''
    """
    return bool(item) and str(item).lower() not in ('default', '*', '', str(DEFAULT_PRIORITY))


def ListUris():
    """ Return list of all RSS uris """
    uris = []
    for uri in config.get_rss():
        uris.append(uri)
    return uris

def convert_filter(text):
    """ Return compiled regex.
        If string starts with re: it's a real regex
        else quote all regex specials, replace '*' by '.*'
    """
    text = text.strip().lower()
    if text.startswith('re:'):
        txt = text[3:].strip()
    else:
        txt = wildcard_to_re(text)
    try:
        return re.compile(txt, re.I)
    except:
        logging.error(Ta('Could not compile regex: %s'), text)
        return None

_EXPIRE_SEC = 3*24*3600 # 3 days
def remove_obsolete(jobs, new_jobs):
    """ Expire G/B links that are not in new_jobs (mark them 'X')
        Expired links older than 3 days are removed from 'jobs'
    """
    now = time.time()
    limit =  now - _EXPIRE_SEC
    olds  = jobs.keys()
    for old in olds:
        tm = jobs[old]['time']
        if old not in new_jobs:
            if jobs[old].get('status', ' ')[0] in ('G', 'B'):
                jobs[old]['status'] = 'X'
        if jobs[old]['status'] == 'X' and tm < limit:
            logging.debug("Purging link %s", old)
            del jobs[old]


LOCK = threading.RLock()
class RSSQueue(object):
    def __init__(self):
        def check_str(p):
            return p is None or p == '' or isinstance(p, str)
        def check_int(p):
            try:
                int(p)
                return True
            except:
                return False

        self.jobs = {}
        try:
            defined = config.get_rss().keys()
            feeds = sabnzbd.load_admin(RSS_FILE_NAME)
            if type(feeds) == type({}):
                for feed in feeds:
                    if feed not in defined:
                        logging.debug('Dropping obsolete data for feed "%s"', feed)
                        continue
                    self.jobs[feed] = {}
                    for link in feeds[feed]:
                        data = feeds[feed][link]
                        if type(data) == type([]):
                            # Convert previous list-based store to dictionary
                            new = {}
                            try:
                                new['status'] = data[0]
                                new['title'] = data[1]
                                new['url'] = data[2]
                                new['cat'] = data[3]
                                new['pp'] = data[4]
                                new['script'] = data[5]
                                new['time'] = data[6]
                                new['prio'] = str(NORMAL_PRIORITY)
                                new['rule'] = 0
                                self.jobs[feed][link] = new
                            except IndexError:
                                del new
                        else:
                            # Consistency check on data
                            try:
                                item = feeds[feed][link]
                                if not isinstance(item, dict) or not isinstance(item.get('title'), unicode):
                                    raise IndexError
                                if item.get('status', ' ')[0] not in ('D', 'G', 'B', 'X'):
                                    item['status'] = 'X'
                                if not isinstance(item.get('url'), unicode): item['url'] = ''
                                item['url'] = item['url'].replace('www.newzbin.com', cfg.newzbin_url())
                                if not check_str(item.get('cat')): item['cat'] = ''
                                if not check_str(item.get('orgcat')): item['orgcat'] = ''
                                if not check_str(item.get('pp')): item['pp'] = '3'
                                if not check_str(item.get('script')): item['script'] = 'None'
                                if not check_str(item.get('prio')): item['prio'] = '-100'
                                if not check_int(item.get('rule', 0)): item['rule'] = 0
                                if not isinstance(item.get('time'), float): item['time'] = time.time()
                                if not check_int(item.get('order', 0)): item.get['order'] = 0
                                self.jobs[feed][link] = item
                            except (KeyError, IndexError):
                                logging.info('Incorrect entry in %s detected, discarding %s', RSS_FILE_NAME, item)

                    remove_obsolete(self.jobs[feed], self.jobs[feed].keys())

        except IOError:
            logging.debug('Cannot read file %s', RSS_FILE_NAME)

        # jobs is a NAME-indexed dictionary
        #    Each element is link-indexed dictionary
        #        Each element is another dictionary:
        #           status : 'D', 'G', 'B', 'X' (downloaded, good-match, bad-match, obsolete)
        #               '*' added means: from the initial batch
        #               '-' added to 'D' means downloaded, but not displayed anymore
        #           title : Title
        #           url : URL or MsgId
        #           cat : category
        #           orgcat : category as read from feed
        #           pp : pp
        #           script : script
        #           prio : priority
        #           time : timestamp (used for time-based clean-up)
        #           order : order in the RSS feed

        self.shutdown = False

    def stop(self):
        self.shutdown = True

    @synchronized(LOCK)
    def run_feed(self, feed=None, download=False, ignoreFirst=False, force=False, readout=True):
        """ Run the query for one URI and apply filters """
        self.shutdown = False

        def dup_title(title):
            """ Check if this title was in this or other feeds
                Return matching feed name
            """
            title = title.lower()
            for fd in self.jobs:
                for lk in self.jobs[fd]:
                    item = self.jobs[fd][lk]
                    if item.get('status', ' ')[0] == 'D' and \
                       item.get('title', '').lower() == title:
                        return fd
            return ''


        if not feed:
            return 'No such feed'

        newlinks = []
        new_downloads = []

        # Preparations, get options
        try:
            feeds = config.get_rss()[feed]
        except KeyError:
            logging.error(Ta('Incorrect RSS feed description "%s"'), feed)
            logging.info("Traceback: ", exc_info = True)
            return T('Incorrect RSS feed description "%s"') % feed

        uri = feeds.uri()
        defCat = feeds.cat()
        if not notdefault(defCat):
            defCat = None
        defPP = feeds.pp()
        if not notdefault(defPP):
            defPP = None
        defScript = feeds.script()
        if not notdefault(defScript):
            defScript = None
        defPrio = feeds.priority()
        if not notdefault(defPrio):
            defPrio = None

        # Preparations, convert filters to regex's
        regexes = []
        reTypes = []
        reCats = []
        rePPs = []
        rePrios = []
        reScripts = []
        reEnabled = []
        for filter in feeds.filters():
            reCat = filter[0]
            if defCat in ('', '*'):
                reCat = None
            reCats.append(reCat)
            rePPs.append(filter[1])
            reScripts.append(filter[2])
            reTypes.append(filter[3])
            regexes.append(convert_filter(filter[4]))
            rePrios.append(filter[5])
            reEnabled.append(filter[6] != '0')
        regcount = len(regexes)

        # Set first if this is the very first scan of this URI
        if feed not in self.jobs:
            self.jobs[feed] = {}
        first = not bool(self.jobs[feed])

        jobs = self.jobs[feed]

        first = first and ignoreFirst

        # Add sabnzbd's custom User Agent
        feedparser.USER_AGENT = 'SABnzbd+/%s' % sabnzbd.version.__version__

        # Check for nzbs.org
        if 'nzbs.org/' in uri and not ('&dl=1' in uri):
            uri += '&dl=1'

        # Read the RSS feed
        if readout:
            uri = uri.replace(' ', '%20')
            logging.debug("Running feedparser on %s", uri)
            d = feedparser.parse(uri.replace('feed://', 'http://'))
            logging.debug("Done parsing %s", uri)
            if not d:
                msg = Ta('Failed to retrieve RSS from %s: %s') % (uri, '?')
                logging.info(msg)
                return unicoder(msg)

            status = d.get('status', 999)
            if status in (401, 402, 403):
                msg = Ta('Do not have valid authentication for feed %s') % feed
                logging.info(msg)
                return unicoder(msg)

            entries = d.get('entries')
            if 'bozo_exception' in d and not entries:
                msg = Ta('Failed to retrieve RSS from %s: %s') % (uri, xml_name(str(d['bozo_exception'])))
                logging.info(msg)
                return unicoder(msg)
            if not entries:
                msg = Ta('RSS Feed %s was empty') % uri
                logging.info(msg)
                return unicoder(msg)
        else:
            entries = jobs.keys()

        order = 0
        # Filter out valid new links
        for entry in entries:
            if self.shutdown: return

            if readout:
                try:
                    link, category = _get_link(uri, entry)
                except (AttributeError, IndexError):
                    link = None
                    category = ''
                    logging.info(Ta('Incompatible feed') + ' ' + uri)
                    logging.info("Traceback: ", exc_info = True)
                    return T('Incompatible feed')
                category = latin1(category)
                # Make sure only latin-1 encodable characters occur
                atitle = latin1(entry.title)
                title = unicoder(atitle)
            else:
                link = entry
                category = jobs[link].get('orgcat', '')
                if category in ('', '*'):
                    category = None
                atitle = latin1(jobs[link].get('title', ''))
                title = unicoder(atitle)

            if link:
                # Make sure spaces are quoted in the URL
                if 'nzbclub.com' in link:
                    link, path = os.path.split(link.strip())
                    link = '%s/%s' % (link, urllib.quote(path))
                else:
                    link = link.strip().replace(' ','%20')

                newlinks.append(link)

                if link in jobs:
                    jobstat = jobs[link].get('status', ' ')[0]
                else:
                    jobstat = 'N'
                if jobstat in 'NGB' or (jobstat == 'X' and readout):
                    # Match this title against all filters
                    logging.debug('Trying title %s', atitle)
                    result = False
                    myCat = defCat
                    myPP = defPP
                    myScript = defScript
                    myPrio = defPrio
                    n = 0

                    # Match against all filters until an postive or negative match
                    for n in xrange(regcount):
                        if reEnabled[n]:
                            if category and reTypes[n] == 'C':
                                found = re.search(regexes[n], category)
                                if not found:
                                    logging.debug("Filter rejected on rule %d", n)
                                    result = False
                                    break
                            else:
                                found = re.search(regexes[n], title)
                                if reTypes[n] == 'M' and not found:
                                    logging.debug("Filter rejected on rule %d", n)
                                    result = False
                                    break
                                if found and reTypes[n] == 'A':
                                    logging.debug("Filter matched on rule %d", n)
                                    result = True
                                    break
                                if found and reTypes[n] == 'R':
                                    logging.debug("Filter rejected on rule %d", n)
                                    result = False
                                    break

                    if len(reCats):
                        if notdefault(reCats[n]):
                            myCat = reCats[n]
                        elif category and not defCat:
                            myCat = cat_convert(category)
                        if myCat:
                            myCat, catPP, catScript, catPrio = cat_to_opts(myCat)
                        else:
                            myCat = catPP = catScript = catPrio = None
                        if notdefault(rePPs[n]):
                            myPP = rePPs[n]
                        elif not (reCats[n] or category):
                            myPP = catPP
                        if notdefault(reScripts[n]):
                            myScript = reScripts[n]
                        elif not (notdefault(reCats[n]) or category):
                            myScript = catScript
                        if rePrios[n] not in (str(DEFAULT_PRIORITY), ''):
                            myPrio = rePrios[n]
                        elif not ((rePrios[n] != str(DEFAULT_PRIORITY)) or category):
                            myPrio = catPrio

                    if cfg.no_dupes() and dup_title(title):
                        if cfg.no_dupes() == 1:
                            logging.info("Ignoring duplicate job %s", atitle)
                            continue
                        else:
                            myPrio = DUP_PRIORITY

                    act = download and not first
                    if link in jobs:
                        act = act and not jobs[link].get('status', '').endswith('*')
                        act = act or force
                        star = first or jobs[link].get('status', '').endswith('*')
                    else:
                        star = first
                    if result:
                        _HandleLink(jobs, link, title, 'G', category, myCat, myPP, myScript,
                                    act, star, order, priority=myPrio, rule=str(n))
                        if act:
                            new_downloads.append(title)
                    else:
                        _HandleLink(jobs, link, title, 'B', category, myCat, myPP, myScript,
                                    False, star, order, priority=myPrio, rule=str(n))
            order += 1

        # Send email if wanted and not "forced"
        if new_downloads and cfg.email_rss() and not force:
            emailer.rss_mail(feed, new_downloads)

        remove_obsolete(jobs, newlinks)
        return ''


    def run(self):
        """ Run all the URI's and filters
        """
        if not sabnzbd.PAUSED_ALL:
            active = False
            feeds = config.get_rss()
            for feed in feeds.keys():
                try:
                    if feeds[feed].enable.get():
                        if not active:
                            logging.info('Starting scheduled RSS read-out')
                        active = True
                        self.run_feed(feed, download=True, ignoreFirst=True)
                        # Wait 15 seconds, else sites may get irritated
                        for x in xrange(15):
                            if self.shutdown:
                                return
                            else:
                                time.sleep(1.0)
                except KeyError:
                    # Feed must have been deleted
                    pass
            if active:
                self.save()
                logging.info('Finished scheduled RSS read-out')


    @synchronized(LOCK)
    def show_result(self, feed):
        if feed in self.jobs:
            try:
                return self.jobs[feed]
            except:
                return {}
        else:
            return {}

    @synchronized(LOCK)
    def save(self):
        sabnzbd.save_admin(self.jobs, sabnzbd.RSS_FILE_NAME)

    @synchronized(LOCK)
    def delete(self, feed):
        if feed in self.jobs:
            del self.jobs[feed]

    @synchronized(LOCK)
    def flag_downloaded(self, feed, id):
        if feed in self.jobs:
            lst = self.jobs[feed]
            for link in lst:
                if lst[link].get('url', '') == id:
                    lst[link]['status'] = 'D'

    @synchronized(LOCK)
    def lookup_url(self, feed, url):
        if url and feed in self.jobs:
            lst = self.jobs[feed]
            for link in lst:
                if lst[link].get('url') == url:
                    return lst[link]
        return None

    @synchronized(LOCK)
    def clear_feed(self, feed):
        # Remove any previous references to this feed name, and start fresh
        if feed in self.jobs:
            del self.jobs[feed]

    @synchronized(LOCK)
    def clear_downloaded(self, feed):
        # Mark downloaded jobs, so that they won't be displayed any more.
        if feed in self.jobs:
            for item in self.jobs[feed]:
                if self.jobs[feed][item]['status'] == 'D':
                    self.jobs[feed][item]['status'] = 'D-'


RE_NEWZBIN = re.compile(r'(newz)(bin|xxx|bin2)\.[\w]+/browse/post/(\d+)', re.I)

def _HandleLink(jobs, link, title, flag, orgcat, cat, pp, script, download, star, order,
                priority=NORMAL_PRIORITY, rule=0):
    """ Process one link """
    if script == '': script = None
    if pp == '': pp = None

    jobs[link] = {}
    jobs[link]['order'] = order
    jobs[link]['orgcat'] = orgcat
    if special_rss_site(link):
        nzbname = None
    else:
        nzbname = sanitize_foldername(title)
    m = RE_NEWZBIN.search(link)
    if m and m.group(1).lower() == 'newz' and m.group(2) and m.group(3):
        if download:
            jobs[link]['status'] = 'D'
            jobs[link]['title'] = title
            logging.info("Adding %s (%s) to queue", m.group(3), title)
            sabnzbd.add_msgid(m.group(3), pp=pp, script=script, cat=cat, priority=priority, nzbname=nzbname)
        else:
            if star:
                jobs[link]['status'] = flag + '*'
            else:
                jobs[link]['status'] = flag
            jobs[link]['title'] = title
            jobs[link]['url'] = m.group(3)
            jobs[link]['cat'] = cat
            jobs[link]['pp'] = pp
            jobs[link]['script'] = script
            jobs[link]['prio'] = str(priority)
    else:
        if download:
            jobs[link]['status'] = 'D'
            jobs[link]['title'] = title
            logging.info("Adding %s (%s) to queue", link, title)
            sabnzbd.add_url(link, pp=pp, script=script, cat=cat, priority=priority, nzbname=nzbname)
        else:
            if star:
                jobs[link]['status'] = flag + '*'
            else:
                jobs[link]['status'] = flag
            jobs[link]['title'] = title
            jobs[link]['url'] = link
            jobs[link]['cat'] = cat
            jobs[link]['pp'] = pp
            jobs[link]['script'] = script
            jobs[link]['prio'] = str(priority)

    jobs[link]['time'] = time.time()
    jobs[link]['rule'] = rule

def _get_link(uri, entry):
    """ Retrieve the post link from this entry
        Returns (link, category)
    """
    link = None
    category = ''
    uri = uri.lower()
    if 'newzbin.' in uri or 'newzxxx.'in uri or 'newzbin2.' in uri:
        link = entry.link
        if not (link and '/post/' in link.lower()):
            # Use alternative link
            link = entry.links[0].href
    else:
        # Try standard link first
        link = entry.link
        if not link:
            link = entry.links[0].href
        if encl_sites(uri, link):
            try:
                link = entry.enclosures[0]['href']
            except:
                pass

    if link and 'http' in link.lower():
        try:
            category = entry.cattext
        except:
            try:
                category = entry.category
            except:
                try: # nzb.su
                    category = entry.tags[0]['term']
                except:
                    try: # nzbmatrix.com
                        category = entry.description
                    except:
                        category = ''
        return link, category
    else:
        logging.warning(Ta('Empty RSS entry found (%s)'), link)
        return None, ''


def special_rss_site(url):
    """ Return True if url describes an RSS site with odd titles
    """
    return cfg.rss_filenames() or 'nzbindex.nl/' in url or 'nzbindex.com/' in url or 'nzbclub.com/' in url


_ENCL_SITES = ('nzbindex.nl', 'nzbindex.com', 'animeusenet.org', 'nzbclub.com')
def encl_sites(url, link):
    """ Return True if url or link match sites that use enclosures
    """
    for site in _ENCL_SITES:
        if site in url or (link and site in link):
            return True
    return False
