#!/usr/bin/env python
#coding: utf-8

from models import Base, Feed, Feedinfo, Entry

from sqlalchemy import create_engine, desc, func
from sqlalchemy.orm import sessionmaker
from datetime import datetime
from ddate import ddate
import feedparser
import sys
import codecs
#import urllib
import urllib2
#import hn
import html2text
import ConfigParser
from argparse import ArgumentParser
from cStringIO import StringIO
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.header import Header
from email import Charset
from email.generator import Generator
import smtplib

def send_mail(sender, receiver, subject, body):
    print 'sending to %s: %s' % (receiver[0], subject)
    Charset.add_charset('utf-8', Charset.QP, Charset.QP, 'utf-8')
    mail = MIMEMultipart('alternative')
    mail['Subject'] = "%s" % Header(subject, 'utf-8')
    mail['From'] = "\"%s\" <%s>" % (Header(sender[0], 'utf-8'), sender[1])
    mail['To'] = "\"%s\" <%s>" % (Header(receiver[0], 'utf-8'), receiver[1])
    textpart = MIMEText(body, 'plain', 'utf-8')
    mail.attach(textpart)
    str_io = StringIO()
    gen = Generator(str_io, False)
    gen.flatten(mail)
    s = smtplib.SMTP('localhost')
    s.sendmail("", receiver[1], str_io.getvalue())

def truncate_text(content, length=100, suffix='...'):
    content = " ".join(content.split())
    if len(content) <= length:
        return content
    else:
        return content[:length].rsplit(' ', 1)[0]+suffix

def mail_daily_digest(session, sender, receiver, prefix):
    print 'mailing daily digest...'
    entries = session.query(Feed, Feedinfo, Entry).\
                filter(Feed.id == Feedinfo.feed_id).\
                filter(Feed.id == Entry.feed_id).\
                filter(Feed.enabled == 1).\
                filter(Feed.daily == 1).\
                filter(Entry.sent == None).\
                order_by(desc(Entry.firstfetched), Feedinfo.title, Entry.title).\
                all()
    body = ''
    count = 0
    for feed, feedinfo, entry in entries:
        count = count + 1
        link = entry.link
        if entry.resolvedlink:
            link = entry.resolvedlink
        try:
            body = body + '=> %s - %s\n' % (entry.firstfetched.strftime('%y%m%d-%H%M'), feedinfo.title)
            body = body + '>> %s\n' % entry.title
            body = body + '%s\n' % truncate_text(entry.get_text(), 250)
            body = body + '%s\n\n' % link
        except:
            print 'ERROR processing entry %s' % entry.id;
            print sys.exc_info()
            print 'not sending mail'
            return
    if count > 0:
        today = datetime.now()
        subject = '%s (%s) - %d entries' % (today.strftime('%y%m%d'), today.strftime('%A'), count)
        body = '%s\n\n%s\n\n%s' % (subject, ddate(), body)
        if prefix != '':
            subject = '%s %s' % (prefix, subject)
        send_mail(sender, receiver, subject, body)
        for feed, feedinfo, entry in entries:
            entry.sent = datetime.now()
    else:
        print 'no unmailed digest-entries found... not sending mail.'

def mail_single_entry(feed, feedinfo, entry, sender, receiver, prefix):
    subject = '%s' % (entry.title)
    if prefix != '':
        subject = '%s %s' % (prefix, subject)
    link = entry.link
    if entry.resolvedlink:
        link = entry.resolvedlink
    body = '%s\n\n' % entry.get_text()
    body = body + '%s\n' % feedinfo.link
    body = body + '%s\n' % link
    sender[0] = feedinfo.title
    send_mail(sender, receiver, subject, body)
    entry.sent = datetime.now()

def mail_single_entries(session, sender, receiver, prefix):
    print 'mailing single entries...'
    count = 0
    entries = session.query(Feed, Feedinfo, Entry).\
                filter(Feed.id == Feedinfo.feed_id).\
                filter(Feed.id == Entry.feed_id).\
                filter(Feed.enabled == 1).\
                filter(Feed.daily == 0 or Feed.daily == None).\
                filter(Entry.sent == None).\
                all()
    for feed, feedinfo, entry in entries:
        mail_single_entry(feed, feedinfo, entry, sender, receiver, prefix)
        count = count + 1
    if count > 0:
        print 'sent %d mails' % count
    else:
        print 'no unmailed single entries found... not sending mail.'

def fetch_readability(link):
    text = hn.upgradeLink(link)
    text = text.decode('utf8')
    return text

def fetch_full_page(link):
    opener = urllib.FancyURLopener({})
    response = opener.open(link)
    html = response.read()
    html = html.decode('utf8')
    text = html2text.html2text(html)
    return text.encode('latin-1', 'replace')

def process_feed_entry(session, feed, entry):
    thisentry = session.query(Entry).\
                filter(Entry.title == entry.title).\
                filter(Entry.link == entry.link).\
                first()
    if thisentry:
        print '  entry already known <%s>' % entry.title
        thisentry.lastfetched = datetime.now()
        session.commit()
        return 0
    else:
        print '  new entry <%s>' % entry.title
        thisentry = Entry(entry)
        if feed.resolveredirects:
            print '    fetching final link <%s>' % entry.link
            request = urllib2.Request(entry.link)
            opener = urllib2.build_opener()
            result = opener.open(request)
            thisentry.resolvedlink = result.url
            print '    final link: <%s>' % result.url
        if feed.fullpage:
            print '    fetching full page <%s>' % entry.link
            thisentry.fullpage = fetch_full_page(entry.link)
        if feed.readability:
            print '    fetching readability <%s>' % entry.link
            thisentry.readability = fetch_readability(entry.link)
        if feed.html2textcontent:
            print '    converting summary'
            h2t = html2text.HTML2Text()
            h2t.body_width = 0
            h2t.inline_links = False
            if feed.html2textignoreimages:
                h2t.ignore_images = True
            if feed.contentcolumn == 'summary':
                thisentry.summary = h2t.handle(thisentry.summary)
            elif feed.contentcolumn == 'content':
                thisentry.content = h2t.handle(thisentry.content)
            elif feed.contentcolumn == 'fullpage':
                thisentry.fullpage = h2t.handle(thisentry.fullpage)
            elif feed.contentcolumn == 'readability':
                thisentry.readability = h2t.handle(thisentry.readability)
        feed.entry.append(thisentry)
        session.commit()
        return 1

def fetch_single_feed(session, feed):
    print 'processing %s' % feed.url
    thisfeedinfo = session.query(Feedinfo).\
                filter(Feedinfo.feed_id==feed.id).\
                first()
    fetched = False
    if thisfeedinfo:
        feed.feedinfo = thisfeedinfo
        if (not feed.feedinfo.nextfetch) or (feed.feedinfo.nextfetch < datetime.now()):
            print 'feed known, fetching...'
            try:
                parser = feedparser.parse(feed.url)
                fetched = True
                feed.feedinfo.update(parser)
            except:
                print 'ERROR parsing feed'
                print sys.exc_info()
        else:
            print 'not fetching before: %s' % feed.feedinfo.nextfetch
    else:
        print 'feed seems to be new, fetching...'
        try:
            parser = feedparser.parse(feed.url)
            fetched = True
            feed.feedinfo = Feedinfo(parser)
        except:
            print 'ERROR parsing feed'
            print sys.exc_info()

    if fetched:
        print 'processing feed entries:'
        entries_new = 0
        entries_total = 0
        for entry in parser.entries:
            entries_total = entries_total + 1
            entries_new = entries_new + process_feed_entry(session, feed, entry)
            session.commit()
        print 'updated %d of %d entries' % (entries_new, entries_total)

def list_all_feeds(session):
    allfeeds = session.query(Feed).\
                order_by(Feed.id)
    totalfeeds = 0
    totalentries = 0
    for feed in allfeeds:
        print feed
        totalfeeds += 1
        totalentries += len(feed.entry)
    print 'TOTAL: %d entries in %d feeds.' % (totalentries, totalfeeds)

def fetch_all_feeds(session):
    print 'fetching all feeds...'
    allfeeds = session.query(Feed).\
                filter_by(enabled=1).\
                order_by(Feed.id)
    for feed in allfeeds:
        fetch_single_feed(session, feed)
        print

def delete_feed(session, feed_id):
    print 'deleting feed %d...' % feed_id
    # TODO implement delete

def reset_feed(session, feed_id):
    print 'resetting feed %d...' % feed_id
    # TODO implement reset

if __name__ == '__main__':
    if (sys.stdout.encoding is None):
        streamWriter = codecs.lookup('utf-8')[-1]
        sys.stdout = streamWriter(sys.stdout)

    config = ConfigParser.ConfigParser()
    config.read('atomstrom.conf')

    dbconnectstring = '%s://%s:%s@%s/%s?charset=utf8' % (
        config.get('database', 'engine'),
        config.get('database', 'user'),
        config.get('database', 'password'),
        config.get('database', 'hostname'),
        config.get('database', 'database'),
    )
    engine = create_engine(dbconnectstring)
    Base.metadata.create_all(engine)

    Session = sessionmaker(bind=engine)
    session = Session()

    #session.add(Feed('http://www.heise.de/newsticker/heise-atom.xml', 1, 0, 0, 1, 1))
    #session.add(Feed('http://blog.schatenseite.de/feed/', 1, 0, 0, 1, 1))

    parser = ArgumentParser(description='Fetch RSS- and Atom-feeds and send mails.')
    parser.add_argument('-f', '--fetch', action='store_true', help='fetch all feeds')
    parser.add_argument('-s', '--single', action='store_true', help='send single mails')
    parser.add_argument('-d', '--daily', action='store_true', help='send daily digest')
    parser.add_argument('-l', '--list', action='store_true', help='list all configured feeds')
    parser.add_argument('-e', '--delete', action='store', type=int, metavar='ID', help='delete feed <ID> from configuration')
    parser.add_argument('-r', '--reset', action='store', type=int, metavar='ID', help='reset data for feed <ID>')
    args = parser.parse_args()

    if args.fetch:
        fetch_all_feeds(session)
    if args.single:
        sender = [config.get('email', 'sender_name'), config.get('email', 'sender_address')]
        receiver = [config.get('email', 'receiver_name'), config.get('email', 'receiver_address')]
        prefix = config.get('email', 'prefix_single')
        mail_single_entries(session, sender, receiver, prefix)
    if args.daily:
        sender = [config.get('email', 'sender_name'), config.get('email', 'sender_address')]
        receiver = [config.get('email', 'receiver_name'), config.get('email', 'receiver_address')]
        prefix = config.get('email', 'prefix_digest')
        mail_daily_digest(session, sender, receiver, prefix)
    if args.list:
        list_all_feeds(session)
    if args.delete:
        delete_feed(session, args.delete)
    if args.reset:
        reset_feed(session, args.reset)
    if not (args.fetch or args.single or args.daily or args.list or args.delete or args.reset):
        parser.print_help()

    session.commit()