# The contents of this file are subject to the Common Public Attribution

# License Version 1.0. (the "License"); you may not use this file except in

# compliance with the License. You may obtain a copy of the License at

# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public

# License Version 1.1, but Sections 14 and 15 have been added to cover use of

# software over a computer network and provide for limited attribution for the

# Original Developer. In addition, Exhibit A has been modified to be consistent

# with Exhibit B.

# 

# Software distributed under the License is distributed on an "AS IS" basis,

# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for

# the specific language governing rights and limitations under the License.

# 

# The Original Code is Reddit.

# 

# The Original Developer is the Initial Developer.  The Initial Developer of the

# Original Code is CondeNet, Inc.

# 

# All portions of the code written by CondeNet are Copyright (c) 2006-2008

# CondeNet, Inc. All Rights Reserved.

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

from pylons import g, config

from r2.models.link import Link

from r2.lib.workqueue import WorkQueue

from r2.lib import s3cp

from r2.lib.utils import timeago, fetch_things2

from r2.lib.db.operators import desc

from r2.lib.scraper import make_scraper

import tempfile

from Queue import Queue

s3_thumbnail_bucket = g.s3_thumb_bucket

media_period = g.media_period

threads = 20

log = g.log

def thumbnail_url(link):

    """Given a link, returns the url for its thumbnail based on its fullname"""

    return 'http:/%s%s.png' % (s3_thumbnail_bucket, link._fullname)

def upload_thumb(link, image):

    """Given a link and an image, uploads the image to s3 into an image

    based on the link's fullname"""

    f = tempfile.NamedTemporaryFile(suffix = '.png')

    image.save(f)

    resource = s3_thumbnail_bucket + link._fullname + '.png'

    log.debug('uploading to s3: %s' % link._fullname)

    s3cp.send_file(f.name, resource, 'image/png', 'public-read', None, False)

    log.debug('thumbnail %s: %s' % (link._fullname, thumbnail_url(link)))

def make_link_info_job(results, link, useragent):

    """Returns a unit of work to send to a work queue that downloads a

    link's thumbnail and media object. Places the result in the results

    dict"""

    def job():

        scraper = make_scraper(link.url)

        thumbnail = scraper.thumbnail()

        media_object = scraper.media_object()

        if thumbnail:

            upload_thumb(link, thumbnail)

        results[link] = (thumbnail, media_object)

    return job

def update_link(link, thumbnail, media_object):

    """Sets the link's has_thumbnail and media_object attributes iin the

    database."""

    if thumbnail:

        link.has_thumbnail = True

    if media_object:

        link.media_object = media_object

    link._commit()

def process_new_links(period = media_period, force = False):

    """Fetches links from the last period and sets their media

    properities. If force is True, it will fetch properities for links

    even if the properties already exist"""

    links = Link._query(Link.c._date > timeago(period), sort = desc('_date'),

                        data = True)

    results = {}

    jobs = []

    for link in fetch_things2(links):

        if link.is_self:

            continue

        if not force and (link.has_thumbnail or link.media_object):

            continue

        jobs.append(make_link_info_job(results, link, g.useragent))

    #send links to a queue

    wq = WorkQueue(jobs, num_workers = 20)

    wq.start()

    wq.jobs.join()

    #when the queue is finished, do the db writes in this thread

    for link, info in results.items():

        update_link(link, info[0], info[1])

def set_media(link):

    """Sets the media properties for a single link."""

    results = {}

    make_link_info_job(results, link, g.useragent)()

    update_link(link, *results[link])