#
# Copyright Michael Orlitzky
#
# http://michael.orlitzky.com/
#
# 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 3 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.
#
# http://www.fsf.org/licensing/licenses/gpl.html
#

require 'src/website'
require 'cgi'

class BliptvMediaFormat
  # This is just a convenience class for parsing two parameters out of
  # an RSS feed: 'url' and 'blip:role'.
  def initialize(line)
    @url = nil
    @role = nil

    url_regex  = /url=\"([^\"]+)\"/
    role_regex = /blip:role=\"([^\"]+)\"/
    url_matches  = url_regex.match(line)
    role_matches = role_regex.match(line)

    if not url_matches.nil? and (url_matches.length) > 1
      @url = url_matches[1]
    end

    if not role_matches.nil? and (role_matches.length > 1)
      @role = role_matches[1]
    end
  end

  def role
    return @role
  end

  def url
    return @url
  end
end


class Bliptv < Website

  VALID_BLIPTV_URL_REGEX = /^(http:\/\/)?blip\.tv\/.*?(\d+)$/

  def self.owns_url?(url)
    return url =~ VALID_BLIPTV_URL_REGEX
  end


  def get_video_url()
    video_id = self.parse_video_id()
    rss_page_url = "http://blip.tv/rss/flash/#{video_id}"
    rss_data = get_page_data(rss_page_url)
    video_url = parse_video_url(rss_data)

    return video_url
  end


  protected;

  def parse_video_id()
    video_id_regex = /(\d+)$/
    matches = video_id_regex.match(@url)

    if matches.nil? or (matches.length < 2)
      raise StandardError.new("Couldn't parse the video id from the URL.")
    else
      return matches[1]
    end
  end


  def choose_best_format(formats)
    # 'formats' is assumed to be an array of BliptvMediaFormat. We
    # return the best one (in terms of video quality).
    formats.each do |f|
      if f.url.nil? or f.role.nil?
        formats.delete(f)
        next
      end

      return f if f.role == "Source"
    end

    if formats.length == 0
      raise StandardError.new("No valid formats in the RSS feed.")
    else
      # Return whatever's left if we don't have a 'Source' video.
      return formats[0]
    end
  end

  def parse_video_url(page_data)
    # All of the elements containing video URLs begin like this.
    media_regex = /^\s*<media:content/

    formats = []
    # Create an array of BliptvMediaFormat from lines matching
    # media_regex.
    page_data.lines.each do |line|
      if (line =~ media_regex)
        bp = BliptvMediaFormat.new(line)
        formats << bp
      end
    end

    # And return the URL from the best one.
    # choose_best_format will raise an error if need be.
    return choose_best_format(formats).url
  end

end