#!/usr/bin/env ruby
#:mode=ruby:

# This program is released under the GNU General Public Licence. Please see
# http://opensource.org/licenses/gpl-license.php for more information.
# Author: Doga Armangil, armangild@yahoo.com

PODCATCHER_WEBSITE = 'http://podcatcher.rubyforge.org/'
PODCATCHER_VERSION = '3.1.6'

# todo: allow files to be selected not only by its MIME type, but also other attributes. Example: --content '^video/ width:680-1024 height:400'
# todo: --proxy option
# todo: download at most one enclosure or media:content per rss item
# todo: support for --content and --language options in search mode
# todo: code refactoring: do not duplicate option handling for 'options' option, factor out conversion between MIME type and file extension, avoid code duplication between implementations of download and search functions
# todo: "item search" - search function that generates a feed containing relevant items of feeds (":item" or ":show" ?)
# todo: option to specify share ratio for torrents
# todo: symlink support in directory (for history, cache etc)
# todo: improve playlist generation when using --strategy cache (only include audio and video content)
# todo: improve --feeds implementation
# todo: resuming of failed media downloads
# todo: --subscriptions option (subscription d/l limit)
# todo: informative exception messages
# todo: only fetch bittorrent metainfo for d/l candidates
# todo: option to download shows concurrently
# todo: "lock" directory to prevent concurrency issues
# todo: option to throttle non-BitTorrent downloads
# 3.1.6: fix a bug whereby a failed content download caused all other content from the same feed to be ignored, fix ruby 1.9 compatibility bug (String#each becomes String#each_line)
# 3.1.5: updated --arguments file format (# now comments out line), updated sponsor message
# 3.1.4: added publication date to content titles in generated playlists, added better handling of invalid URLs in feeds and subscription lists (such URLs are now simply ignored instead of causing the whole document to be skipped)
# 3.1.3: --restrictednames option is now enabled by default, fixed directory name generation bug that allowed '!' character when --perfeed and --restrictednames options were used simultaneously, updated sponsor message
# 3.1.2: modified the help text that appears when --help option is used, updated sponsor message
# 3.1.1: fixed a bug in verbose mode that caused content to be listed twice if it is declared as both RSS enclosure and Media RSS content, changed the sponsor message
# 3.1.0: added support for yyyy and yyyy.mm formats for --horizon parameter
# 3.0.0: added the --cachedir option for explicitely specifying cache directory, added --language option for selecting feeds by language, added the --horizon option that prevents the downloading of content older than a given date, added --restrictednames option for using content subdirectory and file names that are acceptable for restrictive filesystems such as VFAT, http://search.yahoo.com/mrss is now accepted as namespace for RSS Media module, fixed a bug in update checking (flash now only appears if podcatcherstats version is newer than current one), fixed a bug that caused votes to be sent for feeds that have file URLs or filenames.
# 2.0.1: fixed Yahoo Media RSS module handling bug
# 2.0.0: fixed a bug that caused the generation of invalid playlists for feeds containing control characters (such as Ctrl-M) in their title or in the title of one of its entries, added --order option that determines feed order, changed default feed order from 'sequential' to 'random', all content is downloaded by default (not only MP3), changed default cache size to 512MB, added support for the Yahoo Media RSS module (http://search.yahoo.com/mrss), added strategies for downloading content in chronological order (chron_one, chron, chron_all), added -C option that specifies the types of content that are to be received (overrides the default types), added -o option for reading options from a file, added -A option for reading arguments from a file, changed the default download strategy to 'one', added -V alias for --version option, fixed a bug that caused the order of feeds to be ignored in OPML files, fixed a bug that caused downloads of some video files to fail in vodcatcher mode, added --checkforupdate option for informing the user when a new version is available, added --vote option for voting in favour of downloaded podcasts at podcatcherstats.com
# 1.3.7: added status code and content type check when downloading a media file using HTTP, removed some debugging comments
# 1.3.5: fixed a bug that caused wrong cache filenames to be generated when an HTTP redirection was received from a server, added Operating System and processor information to the User-Agent HTTP header sent to web servers
# 1.3.4: fixed the help message
# 1.3.3: added the -p option that assigns a separate cache subfolder to each feed
# 1.3.2: bug fix
# 1.3.1: added robust handling of subscription lists that directly link to media files (such links are now ignored), fixed an OPML generation bug for interrupted searches
# 1.3.0: added search function for online podcast directories such as the iPodder podcast directory, added xspf support
# 1.2.0: added support for decentralized subscription lists (i.e. subscription lists that point to other subscription lists), fixed a bug that sometimes caused an invalid Referer header to be sent in HTTP requests, added the -f option, added support for Atom feeds that do not list items in reverse chronological order, added support for RSS/Atom feeds as command line arguments, added support for Extended M3U and Extended PLS playlist formats, M3U playlists can now also be generated in vodcatcher mode, m3u is now the default type in vodcatcher mode, added "cache" strategy which deprecates -c option
# 1.1.1: added support for iTunes .pcast subscription files
# 1.1.0: names of media files downloaded via BitTorrent are now preserved, done some refactoring so that the script can function as a vodcatcher
# 1.0.4: added support for RSS feeds that do not list items in reverse chronological order
# 1.0.3: fixed an RSS parsing bug that caused enclosures of some feeds to be ignored
# 1.0.2: fixed some minor MP3 file naming bugs
# 1.0.1: names of downloaded MP3 files are now preserved
# 1.0.0: added ATOM support
# 0.4.0: added duplicate removal for MP3, RSS/Atom and OPML URLs and pathnames; added the -i option that attempts to increase the listen-time given to podcasts which frequently release short shows
# 0.3.2: fixed BitTorrent handling bug
# 0.3.1: added robust handling of network exceptions, removed support for Ctrl-C to terminate execution
# 0.3.0: added support for opml format used by podcastalley, added podcast title information in playlists, reduced RAM usage by not loading the history file in memory, history file and playlist are now updated after each download
# 0.2.1: added support for Ctrl-C to terminate execution; added robust handling of some bad command line arguments; (James Carter patch) fixed the "OPML truncation" issue where a bad RSS feed was considered the last of the list
# 0.2.0: added a new download strategy ("one"); added support for more than one OPML argument, fixed some issues
# 0.1.7: bug fix
# 0.1.6: added internal Bittorrent support, fixed flawed handling of some exceptions
# 0.1.5: changed -d option description, added external handling of Bittorrent files
# 0.1.4: bug-fix, robust handling of bad //enclosure/@length attributes, handling of relative enclosure URLs
# 0.1.3: podcast download strategies (and changed default), download retries
# 0.1.2: added TOX playlist support, added HTTP and FTP support for the OPML parameter, done some code clean-up
# 0.1.1: fixed RSS parsing issue
# 0.1.0: initial version

require 'uri'
require 'open-uri'
require 'ostruct'
require 'optparse'
require 'pathname'
require 'date'
require 'cgi'
require 'yaml'
require 'net/http'
require 'rexml/document'

include REXML

#PODCATCHER_ENV = :development
PODCATCHER_ENV = :production

USER_AGENT = "podcatcher/#{PODCATCHER_VERSION} Ruby/#{RUBY_VERSION} #{RUBY_PLATFORM}"
UPDATE_CHECK_INTERVAL = 6 #months

opt = OpenStruct.new
opt.PLAYLIST_TYPES = [:m3u, :smil, :pls, :asx, :tox, :xspf]
opt.playlist_type = opt.PLAYLIST_TYPES[0]
opt.size = 512
opt.content_type = Regexp.new '' 
opt.DESCRIPTION = <<END

Armangil's podcatcher is a podcast client for the command line.
It can download any type of content enclosed in RSS or Atom files, such as 
MP3 or other audio content, video and images. A search function for 
subscribing to feeds is also included. It provides several download 
strategies, supports BitTorrent, offers cache management, and generates 
playlists for media player applications. 

As argument, it accepts feeds (RSS or Atom) or subscription lists 
(OPML or iTunes PCAST), in the form of filenames or URLs (HTTP or FTP).
Alternatively, it accepts one feed or subscription list from the standard 
input.

BitTorrent is supported both internally (through the RubyTorrent library) 
and externally (.torrent files are downloaded, but the user handles
them using a BitTorrent application). The latter is currently the most
reliable method, as RubyTorrent is still in alpha phase.

Concurrency is not handled: simultaneous executions of this program should
target different directories.

Visit http://podcatcher.rubyforge.org/ for more information.

Usage: #{$0} [options] [arguments] 
END

opt.dir = Pathname.new Dir.pwd
opt.CACHEDIR= 'cache'
opt.cachedir = opt.dir + opt.CACHEDIR
opt.memsize = 1_000
opt.empty = false
opt.simulate = false
opt.verbose = false
opt.STRATEGIES = [:one, :new, :back_catalog, :all, :chron, :chron_one, :chron_all, :cache]
opt.strategy = opt.STRATEGIES[0]
opt.retries = 1
opt.torrent_dir = nil
opt.rubytorrent = false
opt.upload_rate = nil #10
opt.itemsize = 0
opt.feeds = 1_000
opt.FUNCTIONS = [:download, :search]
opt.function = opt.FUNCTIONS[0]
opt.per_feed = false
opt.vote = true
opt.check_for_update = true
opt.ORDERS = [:random, :sequential, :alphabetical, :reverse]
opt.order = opt.ORDERS[0]
opt.horizon=nil
opt.language=[]
opt.restricted_names = true

arguments = [] 

option_parser = OptionParser.new() do |c|
	c.banner = opt.DESCRIPTION
	c.separator ""
	c.separator "Options:"
	c.on("-d", "--dir DIR", 
		"Directory for storing application state.",
		"Default value is current directory.\n") do |e|
		contained=false
		#cache directory inside old state directory?
		statedir=opt.dir
		cachedir=opt.cachedir
		loop do
			if cachedir==statedir
				contained=true
				break
			end
			break if cachedir.root?
			cachedir=cachedir.parent
		end
		opt.dir = Pathname.new(Dir.pwd)+e
		#cache directory inside new state directory?
		unless contained
			statedir=opt.dir
			cachedir=opt.cachedir
			loop do
				if cachedir==statedir
					contained=true
					break
				end
				break if cachedir.root?
				cachedir=cachedir.parent
			end
		end
		#new state directory inside cache directory?
		unless contained
			statedir=opt.dir
			cachedir=opt.cachedir
			loop do
				if cachedir==statedir
					contained=true
					break
				end
				break if statedir.root?
				statedir=statedir.parent
			end
		end
		#
		opt.dir.mkdir unless opt.dir.exist?
		exit 1 unless opt.dir.directory?
		if contained
			opt.cachedir = opt.dir + opt.CACHEDIR
		end
	end
	c.on("-D", "--cachedir DIR", 
		"Directory for storing downloaded content.",
		"Default value is the '#{opt.CACHEDIR}' subdirectory",
		"of the state directory (specified by ", 
		"the --dir option).",
		"This option is ignored if this directory",
		"is inside the state directory, or if the",
		"state directory is inside this directory.\n") do |e|
		contained=false
		#cache directory should be outside state directory
		statedir=opt.dir
		cachedir = Pathname.new(Dir.pwd)+e
		loop do
			if cachedir==statedir
				contained=true
				break
			end
			break if cachedir.root?
			cachedir=cachedir.parent
		end
		next if contained
		#state directory should be outside cache directory
		statedir=opt.dir
		cachedir = Pathname.new(Dir.pwd)+e
		loop do
			if cachedir==statedir
				contained=true
				break
			end
			break if statedir.root?
			statedir=statedir.parent
		end
		next if contained
		#accept cache directory
		opt.cachedir=Pathname.new(Dir.pwd)+e
	end
	c.on("-s", "--size SIZE", 
		"Size, in megabytes, of the cache directory", 
		"(specified by the --cachedir option).",
		"0 means unbounded. Default value is #{opt.size}.",
		"This option also sets the upper limit for",
		"the amount of content that can be downloaded",
		"in one session.",
		"Content downloaded during previous sessions",
		"may be deleted by podcatcher in order to",
		"make place for new content.\n") do |e|
		opt.size = e.to_i
		opt.size = nil if opt.size<1
	end
	c.on("-e", "--[no-]empty", 
		"Empty the cache directory before", 
		"downloading content.\n") do |e|
		opt.empty = e
	end
	c.on("-p", "--[no-]perfeed", 
		"Create one subdirectory per feed", 
		"in the cache directory.\n") do |e|
		opt.per_feed = e
	end
	c.on("-S", "--strategy S", opt.STRATEGIES, 
		"Strategy to use when downloading content:",
		"* back_catalog: download any content that",
		" has not been downloaded before; prefer",
		" recent content to older content (may ",
		" download more than one content file per",
		" feed),",
		"* one: download one content file (not ",
		" already downloaded) for each feed, with a ",
		" preference for recent content,",
		"* all: download all content, with a ",
		" preference for recent content; even ",
		" already downloaded content is downloaded ",
		" once again (may download more than one",
		" content file per feed),",
		"* chron: download in chronological order",
		" any content that has not been downloaded ",
		" before; this is useful for audiobook", 
		" podcasts etc (may download more than one",
		" content file per feed),",
		"* chron_one: download the oldest content of",
		" each feed that has not already been ",
		" downloaded, ",
		"* chron_all: download all content in ",
		" chronological order, even if the content",
		" has already been downloaded (may download", 
		" more than one content file per feed), ",
		"* new: download the most recent content ",
		" of each feed, if it has not already been ",
		" downloaded (DEPRECATED: use 'one' instead", 
		" of 'new'),",
		"* cache: generate a playlist for content ",
		" already in cache.",
		"Default value is #{opt.strategy}.\n") do |e|
		opt.strategy = e if e
	end
	c.on("-C", "--content REGEXP", 
		"A regular expression that matches the",
		"MIME types of content to be downloaded.",
		"Examples: '^video/', '^audio/mpeg$'.",
		"Default value is '', which matches any",
		"type of content.\n") do |e|
		begin 
			opt.content_type = Regexp.new(e.downcase) if e
		rescue Exception
			$stderr.puts "Error: ignoring regular expression '#{e}'"
		end 
	end
	c.on("-l", "--language LANG", 
		"A list of language tags separated by",
		"commas. Examples: 'en-us,de', 'fr'.",
		"A feed whose language does not match",
		"this list is ignored. By default, all",
		"feeds are accepted. See",
		"http://cyber.law.harvard.edu/rss/languages.html",
		"and",
		"http://cyber.law.harvard.edu/rss/rss.html#optionalChannelElements",
		"for allowed tags.\n") do |e|
		opt.language = e.split ','
		for i in 0...opt.language.size
			opt.language[i].downcase!
			opt.language[i] = opt.language[i].split '-'
		end
	end
	c.on("-H", "--horizon DATE", 
		"Do not download content older than",
		"the given date. The date has the format",
		"yyyy.mm.dd (example: 2007.03.22) or",
		"yyyy.mm (equivalent to yyyy.mm.01) or",
		"yyyy (equivalent to yyyy.01.01).",
		"#{opt.horizon ? 'Default value is '+opt.horizon.to_s.split('-').join('.') : 'By default, no horizon is specified'}.\n") do |e|
		begin
			date = e.split '.'
			if (1..3).include? date.size
				while date.size < 3
					date << '01'
				end
				opt.horizon = Date.parse date.join('-')
			end
		rescue ArgumentError
		end
	end
	c.on("-r", "--retries N", 
		"Try downloading files (content, feeds",
		"or subscription lists) at most N times", 
		"before giving up. Default value is #{opt.retries}.\n") do |e|
		opt.retries = e.to_i unless e.to_i<1
	end
	c.on("-t", "--type TYPE", opt.PLAYLIST_TYPES, 
		"Type of the playlist written to",
		"standard output. Accepted values are",
		"#{opt.PLAYLIST_TYPES.join ', '}.",
		"Default value is #{opt.playlist_type}.\n") do |e|
		opt.playlist_type = e if e
	end
	c.on("-m", "--memsize N", 
		"Remember last N downloaded content,",
		"and do not download them again. ", 
		"0 means unbounded. Default value is #{opt.memsize}.\n") do |e|
		opt.memsize = e.to_i
		opt.memsize = nil if opt.memsize<1
	end
	c.on("-o", "--order ORDER", opt.ORDERS, 
		"The order in which feeds are traversed",
		"when downloading content:",
		"* random: randomizes the feed order,",
		" so that every feed has an equal chance",
		" when content is downloaded, even if",
		" the cache size is small and the number",
		" of feeds is big,",
		"* alphabetical: orders feeds",
		" alphabetically by using their titles,",
		"* sequential: preserves the argument ",
		" order (and the feed order in",
		" subscription lists),",
		"* reverse: reverses the feed order.",
		"Default value is #{opt.order}.\n") do |e|
		opt.order = e if e
	end
	c.on("-F", "--function FUNCTION", opt.FUNCTIONS, 
		"Used function:",
		"* download: downloads content from",
		" specified feeds,",
		"* search: generates an OPML subscription",
		" list of feeds matching the specified",
		" query; the only options relevant for ",
		" search are -v, -r and -f.",
		"Default value is #{opt.function}.\n") do |e|
		opt.function = e if e
	end
	c.on("-f", "--feeds N", 
		"Do not download more than N feeds", 
		"(when using the download function),",
		"or return the first N relevant feeds", 
		"(when using the search function).",
		"0 means unbounded. Default value is #{opt.feeds}.\n") do |e|
		opt.feeds = e.to_i
		opt.feeds = nil if opt.feeds<1
	end
	c.on("-T", "--torrentdir DIR", 
		"Copy torrent files to directory DIR.",
		"The handling of torrents through an",
		"external BitTorrent client is left to",
		"the user. If this option is not used,",
		"torrents are handled internally (if",
		"RubyTorrent is installed), or else",
		"ignored.\n") do |e|
		dir = Pathname.new e
		if dir.exist? and dir.directory?
			opt.torrent_dir = dir
		end
	end
	c.on("-U", "--uploadrate N", 
		"Maximum upload rate (kilobytes per second)",
		"for the internal BitTorrent client.",
		"#{opt.upload_rate ? 'Default value is '+opt.upload_rate : 'Unbounded by default'}.\n") do |e|
		opt.upload_rate = e.to_i unless e.to_i<1
	end
	c.on("-i", "--itemsize N", 
		"If downloaded content is less than N MB in",
		"size (where N is an integer), fetch other",
		"content of that same feed until this size",
		"is reached. ",
		"Default value is #{opt.itemsize}.",
		"The intent here is to ensure that podcatcher",
		"downloads about as much content from podcasts",
		"that frequently post small content (in", 
		"terms of minutes) as it does from podcasts",
		"that post bigger content less frequently.",
		"This option was more relevant in the early",
		"days of podcasting when content size varied",
		"greatly from one podcast to another. You",
		"would rarely need to use this option today.\n") do |e|
		opt.itemsize = e.to_i unless e.to_i<0
	end
	c.on("-c", "--[no-]cache", 
		"Generate a playlist for content",
		"already in cache.", 
		"DEPRECATED, use '--strategy cache'.\n") do |e|
		opt.strategy = :cache if e
	end
	c.on("-a", "--[no-]asif", 
		"Do not download content, only download",
		"feeds and subscription lists.", 
		"Useful for testing.\n") do |e|
		opt.simulate = e
	end
	c.on("-v", "--[no-]verbose", "Run verbosely.\n") do |e|
		opt.verbose = e
	end
	c.on("-V", "--version", "Display current version and exit.\n") do
		puts PODCATCHER_VERSION
		exit
	end
	c.on("-h", "--help", "Display this message and exit.\n") do
		puts c.to_s
		exit
	end
	c.on("--[no-]restrictednames", 
		'In the cache directory, make the names of', 
		'created subdirectories and files acceptable', 
		'for restrictive file systems such as VFAT', 
		'and FAT, which are used on Windows and MP3', 
		'player devices.',
		"Enabled by default.\n") do |e|
		opt.restricted_names = e
	end
	c.on("--[no-]checkforupdate", 
		"Check once every #{UPDATE_CHECK_INTERVAL} months if a newer ",
		"version is available and display an ",
		"informational message. Enabled by default.\n") do |e|
		opt.check_for_update = e
	end
	c.on("--[no-]vote", 
		"Automatically vote for the downloaded",
		"podcasts at podcatcherstats.com.",
		"Enabled by default.\n") do |e|
		opt.vote = e
	end
	c.on("-A", "--arguments FILENAME_OR_URL", 
		"Read arguments from specified file.",
		"Rules:",
		"* accepts one argument per line,",
		"* ignores empty lines and lines starting",
		"  with #,",
		"* this option may be used several times",
		"  in one command.\n") do |e|
		begin 
			open(e) do |f|
				loop do
					line = f.gets
					break unless line
					line = line.chomp.strip
					next if line.length == 0
					next if line =~ /^\s*#/
					arguments << line
				end
			end
		rescue Exception
			$stderr.puts "Error: arguments file could not be read and will be ignored"
		end
	end
	c.on("-O", "--options FILENAME_OR_URL", 
		"Read options from specified file.",
		"The options file uses the YAML format.\n") do |e|
		loop do
			options = nil
			begin 
				open(e) do |f|
					options = YAML::load(f)
				end
			rescue Exception
				$stderr.puts "Error: options file could not be read and will be ignored"
			end
			break unless options
			break unless options.instance_of? Hash
			options.each() do |option, value|
				case option.downcase
				when 'arguments'
					begin 
						open(value) do |f|
							loop do
								line = f.gets
								break unless line
								line = line.chomp.strip
								next if line.length == 0
								arguments << line
							end
						end
					rescue Exception
						$stderr.puts "Error: arguments file could not be read and will be ignored"
					end
				when 'dir'
					contained=false
					#cache directory inside old state directory?
					statedir=opt.dir
					cachedir=opt.cachedir
					loop do
						if cachedir==statedir
							contained=true
							break
						end
						break if cachedir.root?
						cachedir=cachedir.parent
					end
					opt.dir = Pathname.new(Dir.pwd)+value
					#cache directory inside new state directory?
					unless contained
						statedir=opt.dir
						cachedir=opt.cachedir
						loop do
							if cachedir==statedir
								contained=true
								break
							end
							break if cachedir.root?
							cachedir=cachedir.parent
						end
					end
					#new state directory inside cache directory?
					unless contained
						statedir=opt.dir
						cachedir=opt.cachedir
						loop do
							if cachedir==statedir
								contained=true
								break
							end
							break if statedir.root?
							statedir=statedir.parent
						end
					end
					#
					opt.dir.mkdir unless opt.dir.exist?
					exit 1 unless opt.dir.directory?
					if contained
						opt.cachedir = opt.dir + opt.CACHEDIR
					end
				when 'cachedir'
					contained=false
					#cache directory should be outside state directory
					statedir=opt.dir
					cachedir = Pathname.new(Dir.pwd)+value
					loop do
						if cachedir==statedir
							contained=true
							break
						end
						break if cachedir.root?
						cachedir=cachedir.parent
					end
					next if contained
					#state directory should be outside cache directory
					statedir=opt.dir
					cachedir = Pathname.new(Dir.pwd)+value
					loop do
						if cachedir==statedir
							contained=true
							break
						end
						break if statedir.root?
						statedir=statedir.parent
					end
					next if contained
					#accept cache directory
					opt.cachedir=Pathname.new(Dir.pwd)+value
				when 'size'
					if value.instance_of?(Fixnum)
						opt.size = value
						opt.size = nil if opt.size<1
					end
				when 'strategy'
					opt.strategy = value.to_sym if opt.STRATEGIES.detect{|s| value.to_sym == s}
				when 'type'
					opt.playlist_type = value.to_sym if opt.PLAYLIST_TYPES.detect{|s| value.to_sym == s}
				when 'retries'
					opt.retries = value if value.instance_of?(Fixnum) and value>=1
				when 'memsize'
					if value.instance_of?(Fixnum)
						opt.memsize = value
						opt.memsize = nil if opt.memsize<1
					end
				when 'content'
					begin 
						opt.content_type = Regexp.new(value.downcase)
					rescue Exception
						$stderr.puts "Error: '#{value.downcase}' is not a valid regular expression and will be ignored"
					end
				when 'language'
					opt.language = value.split ','
					for i in 0...opt.language.size
						opt.language[i].downcase!
						opt.language[i] = opt.language[i].split '-'
					end
				when 'order'
					opt.order = value.to_sym if opt.ORDERS.detect{|s| value.to_sym == s}
				when 'function'
					opt.function = value.to_sym if opt.FUNCTIONS.detect{|s| value.to_sym == s}
				when 'feeds'
					if value.instance_of?(Fixnum)
						opt.feeds = value
						opt.feeds = nil if opt.feeds<1
					end
				when 'horizon'
					begin
						date = value.split '.'
						if (1..3).include? date.size
							while date.size < 3
								date << '01'
							end
							opt.horizon = Date.parse date.join('-')
						end
					rescue ArgumentError
					end
				when 'torrentdir'
					dir = Pathname.new value
					if dir.exist? and dir.directory?
						opt.torrent_dir = dir
					end
				when 'uploadrate'
					opt.upload_rate = value if value.instance_of?(Fixnum) and value>=1
				when 'itemsize'
					opt.itemsize = value if value.instance_of?(Fixnum) and value>=0
				when 'perfeed'
					opt.per_feed = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				when 'cache'
					opt.strategy = :cache if value.instance_of?(TrueClass)
				when 'empty'
					opt.empty = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				when 'asif'
					opt.simulate = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				when 'checkforupdate'
					opt.check_for_update = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				when 'vote'
					opt.vote = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				when 'verbose'
					opt.verbose = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				when 'restrictednames'
					opt.restricted_names = value if value.instance_of?(FalseClass) or value.instance_of?(TrueClass)
				end
			end
			break
		end
	end
	c.separator ""
	c.separator "Usage examples:"
	c.separator "    #{$0} --dir ~/podcasts http://podcastalley.com/PodcastAlleyTop50.opml > latest.m3u"
	c.separator ""
	c.separator "    #{$0} --dir ~/podcasts rss.xml atom.xml *.pcast feeds.opml http://host/second.opml > latest.m3u"
	c.separator ""
	c.separator "    #{$0} --dir ~/podcasts --strategy cache > cache.m3u"
	c.separator ""
	c.separator "    cat feeds.opml | #{$0} --dir ~/podcasts > latest.m3u"
	c.separator ""
	c.separator "    #{$0} -vd ~/podcasts -s 500 -m 10_000 -t tox feeds.opml > latest.tox"
	c.separator ""
	c.separator "    #{$0} -vF search 'book health daily source code' 'http://www.ipodder.org/discuss/reader$4.opml' > results.opml"
	c.separator ""
	c.separator "    #{$0} -F search -f 12 mac http://www.podfeed.net/opml/directory.opml > results.opml"
end
option_parser.parse!

class Playlist
	def initialize(playlisttype)
		@playlisttype = playlisttype
		@audio_or_video = Regexp.new '^audio/|^video/'
		@size = 0
	end
	def start()
		@str = ""
		case @playlisttype
		when :tox
			@str = "# toxine playlist \n"
		when :m3u
			@str = "#EXTM3U\n"
		when :pls
			@str = "[playlist]\n"
		when :asx
			@str = <<END
<asx version = "3.0">
END
		when :smil
			@str = <<END
<?xml version="1.0"?>
<!DOCTYPE smil PUBLIC "-//W3C//DTD SMIL 2.0//EN" "http://www.w3.org/2001/SMIL20/SMIL20.dtd">
<smil xmlns="http://www.w3.org/2001/SMIL20/Language">
  <head></head>
  <body>
END
		when :xspf
			@doc = Document.new
			@doc.xml_decl.dowrite
			@doc.add_element Element.new("playlist")
			@doc.root.add_attribute "version", "1"
			@doc.root.add_attribute "xmlns", "http://xspf.org/ns/0/"
			@tracklist = Element.new("trackList")
			@doc.root.add_element @tracklist
		end
		print @str
		@str
	end 
	def add(content)
		return unless content
		if content.mime
			return unless @audio_or_video =~ content.mime
		end
		@size+=1
		feed_title = content.feed_title
		feed_title = '' unless feed_title
		feed_title = sanitize feed_title
		title = content.title
		title = '' unless title
		title = sanitize title
		title = "#{content.pub_date.strftime('%Y.%m.%d')} - "+title if content.pub_date
		entry = ""
		case @playlisttype
		when :m3u
			feed_title = feed_title.gsub(/,/," ")
			title = title.gsub(/,/," ")
			entry = "#EXTINF:-1,[#{feed_title}] #{title}\n#{content.file.to_s}\n"
		when :pls
			entry = "File#{@size}:#{content.file}\nTitle#{@size}:[#{feed_title}] #{title}\nLength#{@size}:-1\n"
		when :asx
			entry = "  <entry><ref href='#{content.file.to_s.gsub(/&/,"&amp;").gsub(/'/,"&apos;").gsub(/"/,"&quot;")}' /></entry>\n"
		when :smil
			entry = "  <ref src='#{content.file.to_s.gsub(/&/,"&amp;").gsub(/'/,"&apos;").gsub(/"/,"&quot;")}' />\n"
		when :tox
			entry = "entry { \n\tidentifier = [#{feed_title}] #{title};\n\tmrl = #{content.file};\n};\n"
		when :xspf
			track = Element.new("track")
			@tracklist.add_element track
			title = Element.new("title")
			title.add_text "[#{feed_title}] #{title}"
			track.add_element title
			location = Element.new("location")
			location.add_text fileurl(content.file) 
			track.add_element location
		end
		@str += entry
		print entry
		entry
	end 
	def finish()
		res = ""
		case @playlisttype
		when :tox
			res = "# end "
		when :asx
			res = <<END
</asx>
END
		when :smil
			res = <<END
  </body>
</smil>
END
		when :pls
			res = "NumberOfEntries=#{@size}\nVersion=2\n"
		when :xspf
			@doc.write $stdout, 0
		end 
		@str += res
		print res
		res
	end 
	def to_s()
		if @doc
			@doc.to_s
		else 
			@str
		end
	end 
private
	def fileurl(path)
		res = ""
		loop do
			path, base = path.split
			if base.root?
				if base.to_s != "/"
					res = "/"+CGI.escape(base.to_s)+res
				end
				break
			end
			res = "/"+CGI.escape(base.to_s)+res
		end
		"file://"+res
	end
	def sanitize(text) #removes invisible characters from text
		return nil unless text
		res = ''
		text.each_byte() do |c|
			case c
			when 0..31, 127 #control chars
				res << ' '
			else
				res << c
			end
		end
		res
	end
end

class Update
	def initialize(dir)
		@now = Time.now
		@data = {'last-check' => @now, 'latest-version' => PODCATCHER_VERSION, 'latest-version-description' => ''}
		@server = URI.parse('http://www.podcatcherstats.com/podcatcher/latest_release')
		@server = URI.parse('http://0.0.0.0:3000/podcatcher/latest_release') if PODCATCHER_ENV == :development
		return unless dir
		return unless dir.directory?
		@file = dir + 'updates'
		if @file.exist? and @file.file?
			begin 
				data = nil
				@file.open() do |f|
					data = YAML.load f
				end
				if data.instance_of? Hash
					if newer_or_equal? data['latest-version']
						data.each() do |key, value|
							case key
							when 'last-check'
								@data[key] = value if value.instance_of? Time and value < @now
							when 'latest-version'
								@data[key] = value if value.instance_of? String
							when 'latest-version-description'
								@data[key] = value if value.instance_of? String
							end
						end
					end
				end
			rescue Interrupt
				@file.delete
			rescue SystemExit
				exit 1
			rescue Exception
				@file.delete
			end
		end
		save 
		exit 1 unless @file.file?
	end
	def check()
		if @now - @data['last-check'] > 60.0 * 60.0 * 24 * 30 * UPDATE_CHECK_INTERVAL
			@data['last-check'] = @now
			begin 
				Net::HTTP.start(@server.host, @server.port) do |http|
					resp = http.get(@server.path, {'User-Agent' => USER_AGENT, 'Connection' => 'close'})
					loop do
						break unless resp.code =~ Regexp.new('^2')
						doc = Document.new resp.body
						break unless doc and doc.root and doc.root.name == 'release'
						version = XPath.first doc.root, 'version'
						break unless version
						break unless newer? version.text 
						description = XPath.first doc.root, 'description'
						if description
							description = description.text.strip
						else 
							description = ''
						end
						@data['latest-version'] = version.join '.'
						@data['latest-version-description'] = description
						save
						break
					end
				#	read resp.body
				end
			rescue Interrupt
			rescue SystemExit
				exit 1
			rescue Exception
			end
		end
		flash
	end
	def to_s()
		res = ''
		if @data
			@data.each() do |key, value|
				res+= "#{key}: #{value}\n"
			end
		end
		res
	end
private
	def flash()
		return unless newer? @data['latest-version'] #if equal? @data['latest-version']
		#constants
		line_length = 70
		p = '**** '
		#
		$stderr.puts ""
		$stderr.puts p+"New release:"
		$stderr.puts p+"Version #{@data['latest-version']} is available at #{PODCATCHER_WEBSITE}."
		if @data['latest-version-description'].size>0
			descr = []
			@data['latest-version-description'].each() do |line|
				descr =  descr + line.chomp.split(' ')
			end
			line = nil
			descr.each() do |word|
				if line and (line + ' ' + word).size>line_length
					$stderr.puts p+line
					line = nil
				end
				if line
					line += ' '+word
				else 
					line = word
				end
				
			end
			$stderr.puts p+line if line
		end
		$stderr.puts ""
	end
	def save()
		@file.open('w') do |f|
			YAML.dump @data, f
		end
	end
	def compare_with(version) # Return values: -1: version<installed_version, 0: version==installed_version, 1: version>installed_version
		return -1 unless version
		version = version.strip.split '.'
		for i in 0...version.size
			version[i] = version[i].to_i
		end
		current_version = PODCATCHER_VERSION.strip.split '.'
		for i in 0...current_version.size
			current_version[i] = current_version[i].to_i
		end
		res = 0
		for i in 0...version.size
			break if i>=current_version.size
			if current_version[i]>version[i]
				res = -1
				break
			end
			if current_version[i]<version[i]
				res = 1
				break
			end
		end
		res
	end
	def newer?(version)
		compare_with(version) == 1
	end
	def newer_or_equal?(version)
		compare_with(version) != -1
	end
	def equal?(version)
		compare_with(version) == 0
	end
end 

class Stats
	def initialize(dir)
		srand
		@now = Time.now
		@data = {'ping-probability' => 1.0}
		@server = URI.parse('http://www.podcatcherstats.com/podcatcher/ping')
		@server = URI.parse('http://0.0.0.0:3000/podcatcher/ping') if PODCATCHER_ENV == :development
		return unless dir
		return unless dir.directory?
		@file = dir + 'votes'
		if @file.exist? and @file.file?
			data = nil
			begin 
				@file.open() do |f|
					data = YAML.load f
				end
			rescue Interrupt
				@file.delete
			rescue SystemExit
				exit 1
			rescue Exception
				@file.delete
			end
			if data.instance_of? Hash
		#		$stderr.puts "votes file read"
				data.each() do |key, value|
					case key
					when 'ping-probability'
						@data[key] = value unless value<0.0 or 1.0<value
					when 'last-session'
						@data[key] = value unless @now<value
					when 'last-ping'
						@data[key] = value unless @now<value
					end
				end
			else 
		#		$stderr.puts "votes file could not be read"
				save
			end
		end
		if @data['last-ping']
			if @data['last-session']
				@data['last-ping'] = nil if @data['last-session']<@data['last-ping']
			else 
				@data['last-ping'] = nil
			end
		end
		save unless @file.exist?
		exit 1 unless @file.file?
	end
	def ping(opt, feeds)
		return unless opt
		return unless feeds
		return if opt.simulate
		#constants
		max_sent_feeds = 50 #max nb of feed info to be sent
		#
		now = Time.now
		begin 
			loop do
				break unless opt.vote
				break unless ping?
		#		$stderr.puts "ping: #{@server}"
				stats = Document.new
				stats.add_element 'downloading'
				#state
				stats.root.add_element state_element #(opt)
				#feeds
				sent_feeds = 0
				feeds.each() do |feed|
					if feed.size > 0 and feed[0].feedurl and feed[0].feedurl.size<255 and (not URI.parse(feed[0].feedurl).instance_of?(URI::Generic)) and sent_feeds < max_sent_feeds
						stats.root.add_element 'feed', {'url' => feed[0].feedurl}
						sent_feeds += 1
					end
				end
				break unless sent_feeds>0
				#send
				stats_str = ''
				stats.write stats_str
				if PODCATCHER_ENV != :production
					$stderr.puts "Sent:"
					$stderr.puts stats_str
				end
				change_state = nil
				Net::HTTP.start(@server.host, @server.port) do |http|
					resp = http.request_post @server.path, stats_str, 'User-Agent' => USER_AGENT, 'Content-Type' => 'application/xml', 'Connection' => 'close'
					if PODCATCHER_ENV != :production
						$stderr.puts "Received:"
						$stderr.puts "#{resp.body}" 
					end
					change resp.body
				end
				@data['last-ping'] = now+0
				break
			end
		rescue Interrupt
	#		$stderr.puts "int1 #{$!}"
		rescue SystemExit
			exit 1
		rescue Exception
	#		$stderr.puts "exc #{$!}"
		end
		@data['last-session'] = now+0
		save
	#	$stderr.puts "#{to_s}"
	end
	def ping_search(opt, query)
		return unless opt
		return unless query
		return if opt.simulate
		now = Time.now
		begin 
			loop do
				break unless opt.vote
				break unless ping?
		#		$stderr.puts "ping.."
				stats = Document.new
				stats.add_element 'searching', {'query' => query}
				#state
				stats.root.add_element state_element
				#send
				stats_str = ''
				stats.write stats_str
		#		$stderr.puts stats_str
				change_state = nil
				Net::HTTP.start(@server.host, @server.port) do |http|
					resp = http.request_post @server.path, stats_str, 'User-Agent' => USER_AGENT, 'Content-Type' => 'application/xml', 'Connection' => 'close'
		#			$stderr.puts "#{resp.body}"
					change resp.body
				end
				@data['last-ping'] = now+0
				break
			end
		rescue Interrupt
	#		$stderr.puts "int1 #{$!}"
		rescue SystemExit
			exit 1
		rescue Exception
	#		$stderr.puts "exc #{$!}"
		end
		@data['last-session'] = now+0
		save
	#	$stderr.puts "#{to_s}"
	end
	def to_s()
		res = ''
		if @data
			@data.each() do |key, value|
				res+= "#{key}: #{value}\n"
			end
		end
		res
	end
private
	def save()
		@file.open('w') do |f| 
			YAML.dump @data, f 
		end 
	end
	def ping?()
		r = rand
	#	$stderr.puts "random: #{r}, ping-probability: #{@data['ping-probability']}"
		return r < @data['ping-probability']
	end
	def change(doc_str)
		return unless doc_str
		begin 
			change_state = Document.new doc_str
			loop do
				break unless change_state
				break unless change_state.root
				break unless change_state.root.name == 'state'
				#ping-probability
				ping = change_state.root.attributes['ping']
				if ping and ping.size>0
					ping = ping.to_f
					unless ping<0.0 or 1.0<ping
						@data['ping-probability'] = ping
					end
				end
				#
				break
			end
		rescue Interrupt
		rescue SystemExit
			exit 1
		rescue Exception
		end
	end
	def state_element #(opt=nil)
		state = Element.new 'state'
		state.add_attribute('ping', @data['ping-probability']) if @data['ping-probability']
		if @data['last-session']
			age_in_seconds = @now - @data['last-session'] #Float
			age_in_days = age_in_seconds/60.0/60.0/24.0
			state.add_attribute('age', age_in_days)
		end
	#	return state unless opt
	#	state.add_attribute('strategy', opt.strategy) 
	#	state.add_attribute('order', opt.order) 
	#	state.add_attribute('cache', opt.size / 1_000_000) if opt.size
	#	state.add_attribute('content', opt.content_type.source) if opt.content_type and opt.content_type.source.size<80
		state
	end
end 

class History
	def initialize(dir)
		@history = dir + "history"
		@history_old = dir + "history-old"
		unless @history.exist?
			@history_old.rename @history if @history_old.exist?
		end
		@history.open("w"){|f|}unless @history.exist?
		exit 1 unless @history.file?
		@history_old.delete if @history_old.exist?
	end
	def mark_old_content(feeds)
		feeds.each() do |feed|
			feed.each() do |content|
				content.in_history = false
			end
		end
		@history.each_line() do |url|
			url = url.chomp
			feeds.each() do |feed|
				feed.each() do |content|
					next if content.in_history
					content.in_history = content.url == url
				end
			end
		end
	end 
	def add(content)
		begin 
			@history.open("a") do |f|
				f.puts content.url
			end
		rescue Interrupt, SystemExit
			exit 1
		rescue Exception
			$stderr.puts "Error: history file could not be updated"
		end
	end 
	def trim(limit)
		begin 
			history_size = 0
			@history.each_line() do |url|
				history_size += 1
			end
			if history_size > limit #shrink
				@history_old.delete if @history_old.exist?
				@history.rename @history_old
				@history.open("w") do |f|
					@history_old.each_line() do |url|
						f.print(url) if history_size <= limit
						history_size -= 1
					end
				end
				@history_old.unlink
			end
		rescue Interrupt, SystemExit
			exit 1
		rescue Exception
			$stderr.puts "Error: failure during history file clean-up."
		end if limit
	end 
end 

class Cache 
	def initialize(opt)
		super()
		@opt = opt
		@@TORRENT = "application/x-bittorrent"
		@@MEDIA_RSS_NS = ['http://search.yahoo.com/mrss/']
		@@MEDIA_RSS_NS << 'http://search.yahoo.com/mrss'
		@@ATOM_NS = Regexp.new "^http://purl.org/atom/ns#"
		#history
		@history = History.new opt.dir
		#stats
		@stats = Stats.new opt.dir
		#cache 
		@cache_dir = opt.cachedir #opt.dir+"cache"
		@cache_dir.mkdir() unless @cache_dir.exist?
		exit 1 unless @cache_dir.directory?
		@cache_dir.each_entry() do |e|
			e = @cache_dir+e
			e = e.cleanpath
			next if e == @cache_dir or e == @cache_dir.parent
			if e.directory? #feed subfolder
				e.each_entry() do |e2|
					e2 = e+e2
					next if e2.directory?
					if opt.empty
						unless opt.simulate or opt.strategy == :cache
							$stderr.puts "Deleting: #{e2}" if opt.verbose
							e2.delete
						end
					end
				end
				e.delete if e.entries.size == 2
			elsif opt.empty
				unless opt.simulate or opt.strategy == :cache
					$stderr.puts "Deleting: #{e}" if opt.verbose
					e.delete
				end
			end
		end
		@cache = @cache_dir.entries.collect() do |e|
			e = @cache_dir+e
			e = e.cleanpath
			next if e == @cache_dir or e == @cache_dir.parent
			if e.file?
				content = OpenStruct.new
				content.file = e
				content.size = e.size
				content.title = e.to_s
				content
			elsif e.directory?
				e.entries.collect() do |e2|
					e2 = e+e2
					if e2.file?
						content = OpenStruct.new
						content.file = e2
						content.size = e2.size
						content.title = e2.to_s
						content
					else 
						nil
					end
				end
			else 
				nil
			end
		end
		@cache.flatten!
		@cache.compact!
		@cache.sort!() do |e,e2|
			e.file.mtime() <=> e2.file.mtime()
		end
	end 
	def createplaylist(urls) 
		playlist = Playlist.new @opt.playlist_type
		if @opt.strategy == :cache
			playlist.start
			@cache.reverse!
			@cache.each() do |content|
				playlist.add content
			end
			playlist.finish
			return playlist.to_s
		end
		playlist.start
		doc = nil
		if urls.size == 0
			$stderr.puts "Reading document from standard input" if @opt.verbose
			begin 
				xml = ""
				$stdin.each() do |e|
					xml += e
				end
				doc = OpenStruct.new
				doc.dom = Document.new(xml)
				doc = nil unless doc.dom
			rescue Interrupt, SystemExit
				exit 1
			rescue Exception
				$stderr.puts "Error: unreadable document"
				doc = nil
			end 
		end
		dochistory = []
		feeds = []
		urls.uniq!
		links = urls.collect() do |e|
			l = OpenStruct.new
			l.url = e
			l
		end
		loop do	
			break if @opt.feeds and feeds.size >= @opt.feeds
			while not doc
				link = links.shift
				break unless link
				if dochistory.detect{|e| e == link.url}
					$stderr.puts "Skipping duplicate: #{link.url}" if @opt.verbose
					next
				end
				$stderr.puts "Fetching: #{link.url}" if @opt.verbose
				dochistory << link.url
				begin 
					doc = fetchdoc(link)
				rescue Interrupt, SystemExit
					exit 1
				rescue Exception
					$stderr.puts "Error: skipping unreadable document"
				end 
			end
			break unless doc
			begin
				if doc.dom.root.name == "opml"
					newlinks = []
					outlines = []
					doc.dom.elements.each("/opml/body") do |body|
						body.elements.each() do |e|
							next unless e.name == 'outline'
							outlines << e
						end
					end
					while outlines.size>0
						outline = outlines.shift
						url = outline.attributes["xmlUrl"]
						url = outline.attributes["url"] unless url
						if url
							begin 
								url = URI.parse(doc.url).merge(url).to_s if doc.url
								link = OpenStruct.new
								link.url = url
								link.referrer = doc.url
								newlinks << link
							rescue URI::InvalidURIError
							end
							next
						end
						new_outlines = []
						outline.elements.each() do |e|
							next unless e.name == 'outline'
							new_outlines << e
						end
						outlines = new_outlines + outlines
					end
					links = newlinks + links
				elsif doc.dom.root.name == "pcast"
					newlinks = []
					XPath.each(doc.dom,"//link[@rel='feed']") do |outline|
						url = outline.attributes["href"]
						next unless url
						begin 
							url = URI.parse(doc.url).merge(url).to_s if doc.url
							link = OpenStruct.new
							link.url = url
							link.referrer = doc.url
							newlinks << link
						rescue URI::InvalidURIError
						end
					end
					links = newlinks + links
				elsif doc.dom.root.namespace =~ @@ATOM_NS
					feed = []
					XPath.each(doc.dom.root,"//*[@rel='enclosure']") do |e2|
						next unless e2.namespace =~ @@ATOM_NS
						content = OpenStruct.new
						XPath.each(e2,"parent::/title/text()") do |node|
							content.title = ""
							node.value.each_line() do |e3| #remove line breaks
								content.title+= e3.chomp+" "
							end
							content.title.strip!
						end
						XPath.each(e2,"parent::/created/text()") do |node|
							pub_date = ""
							node.value.each_line() do |e3| #remove line breaks
								pub_date+= e3.chomp+" "
							end
							begin 
								content.pub_date = DateTime.parse(pub_date.strip, true)
							rescue Exception
							end 
						end
						content.mime = e2.attributes["type"].downcase
						next if @opt.content_type !~ content.mime and content.mime != @@TORRENT
						next if content.mime == @@TORRENT and not (@opt.torrent_dir or @opt.rubytorrent)
						content.feedurl = doc.url
						begin 
							content.url = URI.parse(content.feedurl).merge(e2.attributes["href"]).to_s if content.feedurl
							content.size = e2.attributes["length"].to_i
							content.size = 2 unless content.size and content.size>0 
							content.size = 0 if content.mime == @@TORRENT #not strictly necessary
							feed << content
						rescue URI::InvalidURIError
						end
					end
					#sort by date
					feed.sort!() do |a,b|
						if a.pub_date
							if b.pub_date
								b.pub_date <=> a.pub_date
							else 
								-1
							end
						else 
							if b.pub_date
								1
							else 
								0
							end
						end
					end
					feed.each() do |content|
						$stderr.puts "Enclosure: #{content.url}"
					end if @opt.verbose
					#title
					node = XPath.first(doc.dom,"/feed/title/text()")
					feed_title = ""
					node.value.each_line() do |e3| #remove line breaks
						feed_title += e3.chomp+" "
					end
					feed_title.strip!
					feed.each() do |content|
						content.feed_title = feed_title
					end
					#
					feeds << feed
				elsif doc.dom.root.name = "rss"
					feed = []
					doc.dom.root.elements.each() do |e| #channel
						e.elements.each() do |e1| #item
							title = ''
							XPath.each(e1,"title/text()") do |node|
								title = ''
								node.value.each_line() do |e3| #remove line breaks
									title+= e3.chomp+" "
								end
								title.strip!
							end
							pub_date = nil
							XPath.each(e1,"pubDate/text()") do |node|
								pub_date = ""
								node.value.each_line() do |e3| #remove line breaks
									pub_date+= e3.chomp+" "
								end
								begin 
									pub_date = DateTime.parse(pub_date.strip, true)
								rescue Exception
									pub_date = nil
								end 
							end
							e1.elements.each() do |e2|
								if e2.name == "enclosure"
									content = OpenStruct.new
									content.title = title
									content.pub_date = pub_date
									content.mime = e2.attributes["type"].downcase
									next if @opt.content_type !~ content.mime and content.mime != @@TORRENT
									next if content.mime == @@TORRENT and not (@opt.torrent_dir or @opt.rubytorrent)
									content.feedurl = doc.url
									begin 
										content.url = URI.parse(content.feedurl).merge(e2.attributes["url"]).to_s if content.feedurl
										content.size = e2.attributes["length"].to_i
										content.size = 2 unless content.size and content.size>0 
										content.size = 0 if content.mime == @@TORRENT #not strictly necessary
										feed << content
									rescue URI::InvalidURIError
									end
								elsif @@MEDIA_RSS_NS.include? e2.namespace
									case e2.name
									when 'content'
										content = OpenStruct.new
										content.title = title
										content.pub_date = pub_date
										content.mime = e2.attributes["type"].downcase
										next if @opt.content_type !~ content.mime and content.mime != @@TORRENT
										next if content.mime == @@TORRENT and not (@opt.torrent_dir or @opt.rubytorrent)
										content.feedurl = doc.url
										begin 
											content.url = URI.parse(content.feedurl).merge(e2.attributes["url"]).to_s if content.feedurl
											content.size = e2.attributes["fileSize"].to_i
											content.size = 2 unless content.size and content.size>0 
											content.size = 0 if content.mime == @@TORRENT #not strictly necessary
											feed << content
										rescue URI::InvalidURIError
										end
									when 'group'
										e2.elements.each() do |e4|
											if e4.name == 'content' and @@MEDIA_RSS_NS.include?(e4.namespace)
												content = OpenStruct.new
												content.title = title
												content.pub_date = pub_date
												content.mime = e4.attributes["type"].downcase
												next if @opt.content_type !~ content.mime and content.mime != @@TORRENT
												next if content.mime == @@TORRENT and not (@opt.torrent_dir or @opt.rubytorrent)
												content.feedurl = doc.url
												begin 
													content.url = URI.parse(content.feedurl).merge(e4.attributes["url"]).to_s if content.feedurl
													content.size = e4.attributes["fileSize"].to_i
													content.size = 2 unless content.size and content.size>0 
													content.size = 0 if content.mime == @@TORRENT #not strictly necessary
													feed << content
												rescue URI::InvalidURIError
												end
												break
											end
										end
									end
									
								end
							end if e1.name == "item"
						end if e.name == "channel"
					end
					#remove duplicates (duplication occurs in particular for content declared as both enclosure and Media RSS content)
					for i in 0...feed.size
						content = feed[i]
						next unless content
						for j in i+1...feed.size
							next unless feed[j]
							feed[j] = nil if feed[j].url == content.url
						end
					end
					feed.compact!
					#sort by date
					feed.sort!() do |a,b|
						if a.pub_date
							if b.pub_date
								b.pub_date <=> a.pub_date
							else 
								-1
							end
						else 
							if b.pub_date
								1
							else 
								0
							end
						end
					end
					feed.each() do |content|
						$stderr.puts "Enclosure: #{content.url}"
					end if @opt.verbose
					#title
					node = XPath.first(doc.dom,"//channel/title/text()")
					feed_title = ""
					node.value.each_line() do |e3| #remove line breaks
						feed_title += e3.chomp+" "
					end
					feed_title.strip!
					feed.each() do |content|
						content.feed_title = feed_title
					end
					#language
					if @opt.language.size > 0
						loop do
							node = XPath.first doc.dom, '//channel/language/text()'
							break unless node
							break unless node.value
							feed_lang = node.value.strip.downcase.split '-'
							break if feed_lang.size == 0
							langmatch = @opt.language.collect() do |lang|
								next false if feed_lang.size < lang.size
								matches = true
								for i in 0...lang.size
									next if lang[i] == feed_lang[i]
									matches = false
								end
								matches
							end
							feeds << feed if langmatch.include? true
							break
						end
					else
						feeds << feed
					end
				end
			rescue Interrupt, SystemExit
				exit 1
			rescue Exception
				$stderr.puts "Error: skipping document because of an internal error"
			end
			doc = nil
		end
		#remove content older than the horizon date
		if @opt.horizon
			feeds.each() do |feed|
				for i in 0...feed.size
					if feed[i].pub_date
						feed[i] = nil if feed[i].pub_date < @opt.horizon
					else
						feed[i] = nil
					end
				end
				feed.compact!
			end
		end
		#apply download strategy
		@history.mark_old_content feeds
		if @opt.strategy == :chron or @opt.strategy == :chron_one or @opt.strategy == :chron_all
			feeds.each() do |feed|
				feed.reverse!
			end
			@opt.strategy = :back_catalog if @opt.strategy == :chron
			@opt.strategy = :one if @opt.strategy == :chron_one
			@opt.strategy = :all if @opt.strategy == :chron_all
		end
		case @opt.strategy #remove ignored content
		when :new
			feeds.each() do |feed|
				in_hist = nil
				for i in 0...feed.size
					if feed[i].in_history
						in_hist = i
						break
					end
				end
				feed.slice! in_hist...feed.size if in_hist
			end
		when :all
		else 
			feeds.each() do |feed|
				for i in 0...feed.size
					feed[i] = nil if feed[i].in_history
				end
				feed.compact!
			end
		end
		if @opt.strategy == :new or @opt.strategy == :one 
			feeds.each() do |feed|
				itemsize = 0
				index = nil
				for i in 0...feed.size
					itemsize += feed[i].size
					if itemsize >= @opt.itemsize
						index = i+1
						break
					end
				end
				feed.slice! index...feed.size if index
			end
		end
		#feed order
		case @opt.order
		when :random
			srand
			feeds.sort!() do |a,b|
				if a.size>0
					if b.size>0
						rand(3)-1
					else 
						-1
					end
				else 
					if b.size>0
						1
					else 
						0
					end
				end
			end
		when :alphabetical
			feeds.sort!() do |a,b|
				if a.size>0
					if b.size>0
						a[0].feed_title <=> b[0].feed_title
					else 
						-1
					end
				else 
					if b.size>0
						1
					else 
						0
					end
				end
			end
		when :reverse
			feeds.reverse!
		end
		#remove duplicate content
		feeds.each() do |feed|
			feed.each() do |content|
				next unless content
				dup = false
				feeds.each() do |f|
					for i in 0...f.size
						next unless f[i]
						if f[i].url == content.url
							f[i] = nil if dup
							dup = true
						end
						$stderr.puts "Removed duplicate: #{content.url}" unless f[i] or (not @opt.verbose)
					end
				end
			end
			feed.compact!
		end
		#send usage statistics
		@stats.ping @opt, feeds
		#fetch torrent metainfo files
		feeds.each() do |feed|
			feed.each() do |content|
				next if content.mime != @@TORRENT
				content.mime = nil
				begin 
					$stderr.puts "Fetching torrent metainfo: #{content.url}" if @opt.verbose
					content.metainfo = RubyTorrent::MetaInfo.from_location content.url
					content.size = content.metainfo.info.length
					content.mime = case content.metainfo.info.name.downcase
						when /\.mp3$/
							"audio/mpeg"
						when /\.wma$/
							"audio/x-ms-wma"
						when /\.mpg$|\.mpeg$|\.mpe$|\.mpa$|\.mp2$|\.mpv2$/
							"video/mpeg"
						when /\.mov$|\.qt$/
							"video/quicktime"
						when /\.avi$/
							"video/x-msvideo"
						when /\.wmv$/
							"video/x-ms-wmv"
						when /\.asf$/
							"video/x-ms-asf"
						when /\.m4v$|\.mp4$|\.mpg4$/
							"video/mp4"
						else 
							nil
						end 
					content.url = nil unless content.mime
					content.url = nil unless (@opt.content_type =~ content.mime)
					content.url = nil unless content.metainfo.info.single?
				rescue Interrupt
					content.url = nil
					$stderr.puts "Error: unreadable torrent metainfo" if @opt.verbose
				rescue SystemExit
					exit 1
				rescue Exception
					content.url = nil
					$stderr.puts "Error: unreadable torrent metainfo" if @opt.verbose
				end 
			end
			for i in 0...feed.size
				feed[i] = nil unless feed[i].url
			end
			feed.compact!
		end
		#fetch enclosures
		item = total = 0
		@cache.each() do |e|
			total+= e.size
		end
		torrents = []
		torrentfiles = []
		inc = 1
		while inc>0
			inc = 0
			itemsize = 0
			feeds.each do |e|
				#find next enclosure in feed
				content = e.shift
				unless content
					itemsize = 0
					next
				end
				#make place in cache
				while @opt.size and content.size+inc+total > @opt.size
					break if @opt.simulate
					f = @cache.shift
					break unless f
					total-= f.size
					parent = f.file.parent
					$stderr.puts "Deleting: #{f.file}" if @opt.verbose
					f.file.delete 
					if parent.parent != @opt.dir and parent.entries.size == 2
						#delete empty feed subfolder
						$stderr.puts "Deleting: #{parent}" if @opt.verbose
						parent.delete 
					end
				end
				unless @opt.simulate
					break if @opt.size and content.size+inc+total > @opt.size
				end
				#download
				1.upto(@opt.retries) do |i|
					begin 
						if content.metainfo
							if @opt.torrent_dir
								loop do
									content.file = @opt.torrent_dir+(Time.now.to_f.to_s+".torrent")
									break unless content.file.exist?
									sleep 1
								end
								$stderr.puts "Copying: #{content.url} to #{content.file}" if @opt.verbose and i == 1
								if not @opt.simulate 
									if content.feedurl and (content.feedurl =~ %r{^http:} or content.feedurl =~ %r{^ftp:})
										open(content.url, "User-Agent" => USER_AGENT, "Referer" => content.feedurl) do |fin|
											content.file.open("wb") do |fout|
												fin.each_byte() do |b|
													fout.putc b
												end
											end
										end
									else 
										open(content.url, "User-Agent" => USER_AGENT) do |fin|
											content.file.open("wb") do |fout|
												fin.each_byte() do |b|
													fout.putc b
												end
											end
										end
									end
								end
							else
								$stderr.puts "Fetching in background: #{content.url}" if @opt.verbose and i == 1
								unless @opt.simulate
									content.file = filename(content, @cache_dir)
									package = RubyTorrent::Package.new content.metainfo, content.file.to_s
									bt = RubyTorrent::BitTorrent.new content.metainfo, package, :dlratelim => nil, :ulratelim => @opt.upload_rate, :http_proxy => ENV["http_proxy"]
									torrents << bt
									torrentfiles << content
								end
								inc+= content.size
								itemsize+= content.size
							end
						else 
							$stderr.puts "Fetching: #{content.url} (#{content.size.to_s} bytes)" if @opt.verbose and i == 1
							if not @opt.simulate 
								headers = {"User-Agent" => USER_AGENT}
								headers["Referer"] = content.feedurl if content.feedurl and (content.feedurl =~ %r{^http:} or content.feedurl =~ %r{^ftp:})
								content.download_url = content.url unless content.download_url
								open(content.download_url, headers) do |fin|
									if fin.base_uri.instance_of?(URI::HTTP) 
										if fin.status[0] =~ Regexp.new('^3') 
											content.download_url = fin.meta['location']
											raise "redirecting"
										elsif fin.status[0] !~ Regexp.new('^2') 
											raise 'failed'
										end
									end
									# write content to cache
									content.redirection_url = fin.base_uri.to_s # content.redirection_url is used for finding the correct filename in case of redirection
									content.redirection_url = nil if content.redirection_url.eql?(content.url)
									content.file = filename(content, @cache_dir)
									content.file.open("wb") do |fout|
										fin.each_byte() do |b|
											fout.putc b
										end
									end
								end
								content.size = content.file.size
								@history.add content 
							end
							playlist.add(content)
							inc+= content.size
							itemsize+= content.size
						end
						break
					rescue Interrupt
					rescue SystemExit
						exit 1
					rescue Exception
					end 
					$stderr.puts "Attempt #{i} aborted" if @opt.verbose
					if content.file and i == @opt.retries
						if content.file.exist?
							parent = content.file.parent
							content.file.delete
							if parent.parent != @opt.dir and parent.entries.size == 2
								#delete empty feed subfolder
								parent.delete
							end
						end
						content.file = nil
					end
					sleep 5
				end
				redo unless content.file # skip unavailable enclosures
				redo if @opt.itemsize > itemsize
				itemsize = 0
			end
			total+=inc
		end 
		#shut down torrents
		if torrents.length > 0
			$stderr.puts "Fetching torrents (duration: 30min to a couple of hours) " if @opt.verbose
			bt = torrents[0]
			completion = torrents.collect() do |e|
				e.percent_completed
			end
			while torrents.length > 0
				sleep 30*60
				for i in 0...torrents.length
					c = torrents[i].percent_completed
					complete = torrents[i].complete? 
					$stderr.puts "Fetched: #{c}% of #{torrentfiles[i].url} " if @opt.verbose
					if complete or c == completion[i]
						begin 
							torrents[i].shutdown
						rescue SystemExit
							exit 1
						rescue Interrupt, Exception
						end 
						if complete
							playlist.add(torrentfiles[i])
							@history.add torrentfiles[i]
						else                                                        
							$stderr.puts "Aborted: #{torrentfiles[i].url}" if @opt.verbose
							begin 
								torrentfiles[i].file.delete if torrentfiles[i].file.exist?
								torrentfiles[i] = nil
							rescue Interrupt, SystemExit
								exit 1
							rescue Exception
							end 
						end
						torrents[i] = nil
						torrentfiles[i] = nil
						completion[i] = nil
						next
					end
					completion[i] = c
				end 
				torrents.compact!
				torrentfiles.compact!
				completion.compact!
			end
			begin 
				bt.shutdown_all
			rescue Interrupt, SystemExit
				exit 1
			rescue Exception
			end
			$stderr.puts "BitTorrent stopped" if @opt.verbose
		end
		playlist.finish
		@history.trim(@opt.memsize) unless @opt.simulate or @opt.strategy == :cache
		playlist.to_s
	end 
private
	def fetchdoc(link)
		doc = ""
		1.upto(@opt.retries) do |i|
			begin 
				if link.url =~ %r{^http:} or link.url =~ %r{^ftp:}
					if link.referrer and (link.referrer =~ %r{^http:} or link.referrer =~ %r{^ftp:})
						open(link.url, "User-Agent" => USER_AGENT, "Referer" => link.referrer) do |f|
							break if f.content_type.index "audio/"
							break if f.content_type.index "video/"
							f.each_line() do |e|
								doc += e
							end
						end
					else 
						open(link.url, "User-Agent" => USER_AGENT) do |f|
							break if f.content_type.index "audio/"
							break if f.content_type.index "video/"
							f.each_line() do |e|
								doc += e
							end
						end
					end
				else 
					open(link.url) do |f|
						f.each_line() do |e|
							doc += e
						end
					end
				end
				break
			rescue Interrupt
			rescue SystemExit
				exit 1
			rescue Exception
			end 
			$stderr.puts "Attempt #{i} aborted" if @opt.verbose
			doc = ""
			sleep 5
		end
		res = OpenStruct.new
		begin 
			res.dom = Document.new doc
		rescue Exception
		end 
		if res.dom
			res.url = link.url
		else 
			res = nil
		end
		res
	end 
	def filename(content, dir) #produce filename for content to be downloaded
		begin #per-feed subfolder
			if @opt.per_feed and content.feed_title and content.feed_title.size > 0
				newdir = dir+content.feed_title
				newdir = dir+content.feed_title.gsub(/[\\\/:*?\"<>|!]/, ' ').gsub(/-+/,'-').gsub(/\s+/,' ').strip if @opt.restricted_names
				if newdir.exist?
					if newdir.directory?
						dir = newdir
					end
				else 
					newdir.mkdir
					dir = newdir
				end
			end
		rescue Exception
		#	$stderr.puts "error: #{$!}"
		end
		ext = [""]
		if content.metainfo
			begin 
				ext = ["."+content.metainfo.info.name.split(".").reverse[0]]
			rescue Exception
			end 
		else 
			ext = case content.mime.downcase
				when "audio/mpeg"
					[".mp3"]
				when "audio/x-mpeg"
					[".mp3"]
				when "audio/x-ms-wma"
					[".wma"]
				when "audio/x-m4a"
					[".m4a"]
				when "video/mpeg"
					[".mpg",".mpeg",".mpe",".mpa",".mp2",".mpv2"]
				when "video/quicktime"
					[".mov",".qt"]
				when "video/x-msvideo"
					[".avi"]
				when "video/x-ms-wmv"
					[".wmv"]
				when "video/x-ms-asf"
					[".asf"]
				when "video/mp4"
					[".m4v", ".mp4",".mpg4"]
				when "video/x-m4v"
					[".m4v", ".mp4",".mpg4"]
				else
					[""]
				end 
		end
		#name from url?
		name = nil
		begin 
			if content.metainfo
				name = content.metainfo.info.name
				name = nil if (dir+name).exist?
			else 
				urlname = nil
				urlname = URI.split(content.redirection_url)[5].split("/")[-1] if content.redirection_url
				urlname = URI.split(content.url)[5].split("/")[-1] unless urlname
				ext.each() do |e|
					if e.length == 0 or urlname[-e.length..-1].downcase == e
						name = urlname
						name = URI.unescape(name)
						name = nil if (dir+name).exist?
						break if name
					end
				end
			end
		rescue Exception
		end 
		#unique name?
		loop do
			name = Time.now.to_f.to_s+ext[0]
			break unless (dir+name).exist?
			sleep 1
		end unless name
		dir+name
	end 
end
class OPML
	def initialize(title = nil)
		@doc = Document.new
		@doc.xml_decl.dowrite
		@doc.add_element Element.new("opml")
		@doc.root.add_attribute "version", "1.1"
		head = Element.new("head")
		@doc.root.add_element head
		if title
			titlee = Element.new("title")
			titlee.text = title
			head.add_element titlee
		end
		@body = Element.new("body")
		@doc.root.add_element @body
		@size = 0
	end
	def add(feedurl, text=nil)
		e = Element.new("outline")
		e.add_attribute("text", text) if text
		e.add_attribute "type", "link"
		e.add_attribute "url", feedurl
		@body.add_element e
		@size += 1
	end 
	def write()
		@doc.write $stdout, 0
	end
	def size()
		@size
	end 
end 

class Query
	def initialize(opt, query)
		@@ATOM_NS = Regexp.new '^http://purl.org/atom/ns#'
		@@ITUNES_NS = 'http://www.itunes.com/dtds/podcast-1.0.dtd'
		@opt = opt
		if query
			@query = query.downcase.split
			@query = nil if @query.size == 0
		end
		@stats = Stats.new opt.dir
	end
	def search(urls)
		res = []
		begin 
			newpaths = []
			dochistory = []
			paths = []
			if urls.size == 0
				$stderr.puts "Reading subscriptions from standard input" if @opt.verbose
				begin 
					xml = ""
					$stdin.each() do |e|
						xml += e
					end
					path = OpenStruct.new
					path.doc = Document.new(xml)
					if path.doc and path.doc.root
						path.relevance = 0
						newpaths << path
					end
				rescue Interrupt, SystemExit
					raise
				rescue Exception
					$stderr.puts "Error: unreadable subscriptions"
				end 
			else 
				newpaths = urls.uniq.collect() do |e|
					path = OpenStruct.new
					path.url = e
					path
				end
				newpaths = newpaths.collect() do |path|
					$stderr.puts "Fetching: #{path.url}" if @opt.verbose
					dochistory << path.url
					path.doc = fetchdoc(path)
					if path.doc
						path.relevance = 0
						path
					else 
						$stderr.puts "Skipping unreadable document" if @opt.verbose
						nil
					end
				end
				newpaths.compact!
			end
			#send usage statistics
			@stats.ping_search @opt, @query.join(' ')
			#
			loop do
				break if @opt.feeds and res.size >= @opt.feeds
				begin
					newpaths.sort!() do |path1, path2|
						path2.relevance <=> path1.relevance
					end
					paths = newpaths + paths
					newpaths = []
					path = nil
					loop do
						path = paths.shift
						break unless path
						if path.doc
							break
						else
							if dochistory.detect{|e| e == path.url}
								$stderr.puts "Skipping duplicate: #{path.url}" if @opt.verbose
								next
							end
							$stderr.puts "Fetching: #{path.url}" if @opt.verbose
							dochistory << path.url
							path.doc = fetchdoc(path)
							if path.doc
								break
							end
							$stderr.puts "Error: skipping unreadable document"
						end
					end
					break unless path
					if path.doc.root.name == "opml"
						#doc relevance
						path.relevance += relevance_of(XPath.first(path.doc, "/opml/head/title/text()"))
						#outgoing links
						XPath.each(path.doc,"//outline") do |outline|
							url = outline.attributes["xmlUrl"]
							url = outline.attributes["url"] unless url
							next unless url
							begin 
								url = URI.parse(path.url).merge(url).to_s if path.url
							rescue Interrupt, SystemExit
								raise
							rescue Exception
							end
							newpath = OpenStruct.new
							newpath.url = url
							newpath.referrer = path.url
							#link relevance
							newpath.relevance = path.relevance
							XPath.each(outline, "ancestor-or-self::outline") do |e|
								newpath.relevance += relevance_of(e.attributes["text"])
							end
							#
							newpaths << newpath
						end
					elsif path.doc.root.name == "pcast"
						#outgoing links
						XPath.each(path.doc,"/pcast/channel") do |channel|
							link = XPath.first(channel, "link[@rel='feed']")
							next unless link
							url = link.attributes["href"]
							next unless url
							begin 
								url = URI.parse(path.url).merge(url).to_s if path.url
							rescue Interrupt, SystemExit
								raise
							rescue Exception
							end
							newpath = OpenStruct.new
							newpath.url = url
							newpath.referrer = path.url
							#link relevance
							newpath.relevance = path.relevance
							newpath.relevance += relevance_of(XPath.first(channel, "title/text()"))
							newpath.relevance += relevance_of(XPath.first(channel, "subtitle/text()"))
							#
							newpaths << newpath
						end
					elsif path.doc.root.namespace =~ @@ATOM_NS and path.url
						#doc relevance
						title = nil
						begin 
							XPath.each(path.doc.root,"/*/*") do |e|
								next unless e.namespace =~ @@ATOM_NS
								next unless e.name == "title" or e.name == "subtitle"
								title = e.text if e.name == "title"
								path.relevance += relevance_of(e.text)
							end
						rescue Interrupt, SystemExit
							raise
						rescue Exception
							#$stderr.puts "error: #{$!}"
						end 
						if path.relevance > 0
							$stderr.puts "Found: #{title} (relevance: #{path.relevance})" if @opt.verbose
							if title
								path.title = ""
								title.value.each() do |e3| #remove line breaks
									path.title+= e3.chomp+" "
								end
								path.title.strip!
							end
							res << path
						end
					elsif path.doc.root.name = "rss" and path.url
						#doc relevance
						title = XPath.first(path.doc, "//channel/title/text()")
						path.relevance += relevance_of(title)
						path.relevance += relevance_of(XPath.first(path.doc, "//channel/description/text()"))
						begin 
							XPath.each(path.doc.root,"//channel/*") do |e|
								next unless e.name == "category"
								if e.namespace == @@ITUNES_NS
									XPath.each(e, "descendant-or-self::*") do |e2|
										next unless e2.name == "category"
										path.relevance += relevance_of(e2.attributes["text"])
									end
								else 
									path.relevance += relevance_of(e.text) 
								end
							end
						rescue Interrupt, SystemExit
							raise
						rescue Exception
							#$stderr.puts "error: #{$!}"
						end 
						if path.relevance > 0
							$stderr.puts "Found: #{title} (relevance: #{path.relevance})" if @opt.verbose
							if title
								path.title = ""
								title.value.each() do |e3| #remove line breaks
									path.title+= e3.chomp+" "
								end
								path.title.strip!
							end
							res << path
						end
					end
				rescue Interrupt, SystemExit
					raise
				rescue Exception
					$stderr.puts "Error: skipping unreadable document"
				end 
			end
		rescue Interrupt, SystemExit
			$stderr.puts "Execution interrupted"
		rescue Exception
		end 
		result = nil
		while not result
			begin 
				res.sort!() do |path1, path2|
					path2.relevance <=> path1.relevance
				end
				opml = OPML.new "Search results for \"#{@query.collect(){|e| "#{e} "}}\""
				res.each() do |path|
					opml.add path.url, path.title
				end
				result = opml
			rescue Exception
			end 
		end
		result.write
		result
	end 
private
	def relevance_of(meta)
		return 0 unless meta
		unless meta.kind_of? String #Text todo: resolve entities
			meta = meta.value
		end
		meta = meta.downcase
		meta = meta.split
		res = 0
		@query.each() do |e|
			meta.each() do |e2|
				res += 1 if e2.index(e)
			end
		end
		res
	end 
	def fetchdoc(link)
		doc = ""
		1.upto(@opt.retries) do |i|
			begin 
				if link.url =~ %r{^http:} or link.url =~ %r{^ftp:}
					if link.referrer and (link.referrer =~ %r{^http:} or link.referrer =~ %r{^ftp:})
						open(link.url, "User-Agent" => USER_AGENT, "Referer" => link.referrer) do |f|
							break if f.content_type.index "audio/"
							break if f.content_type.index "video/"
							f.each_line() do |e|
								doc += e
							end
						end
					else 
						open(link.url, "User-Agent" => USER_AGENT) do |f|
							break if f.content_type.index "audio/"
							break if f.content_type.index "video/"
							f.each_line() do |e|
								doc += e
							end
						end
					end
				else 
					open(link.url) do |f|
						f.each_line() do |e|
							doc += e
						end
					end
				end
				break
			rescue Interrupt
			rescue SystemExit
				break
			rescue Exception
			end 
			$stderr.puts "Attempt #{i} aborted" if @opt.verbose
			doc = ""
			sleep 5
		end
		res = nil
		begin 
			res = Document.new doc
		rescue Exception
		end 
		res = nil unless res and res.root
		res
	end 
end

opt.size *= 1_000_000 if opt.size
opt.upload_rate *= 1024 if opt.upload_rate
opt.itemsize *= 1_000_000 
arguments = arguments + ARGV

unless opt.check_for_update
	$stderr.puts "Disabling update check." if opt.verbose
end

unless opt.vote
	$stderr.puts "Disabling the sending of anonymous usage statistics." if opt.verbose
end

begin 
	require "rubytorrent"
	opt.rubytorrent = true
	$stderr.puts "RubyTorrent detected." if opt.verbose
rescue Interrupt, SystemExit
	exit 1
rescue Exception
end

if opt.function == :download
	cache = Cache.new opt
	cache.createplaylist arguments
elsif opt.function == :search
	dir = Query.new opt, arguments.shift
	dir.search arguments
end

if opt.check_for_update
	update = Update.new opt.dir
	update.check
end

if opt.verbose
        $stderr.puts ""
        $stderr.puts "   *********************************************************************"
        $stderr.puts "   ****   Qworum - A platform for web-based services      (sponsor) ****"
        $stderr.puts "   *********************************************************************"
        $stderr.puts "   ****   Sell and buy services:                                    ****"
        $stderr.puts "   ****   Host services on your own domain; sell them to websites   ****"
        $stderr.puts "   ****   or businesses on the service marketplace.                 ****"
        $stderr.puts "   ****                                                             ****"
        $stderr.puts "   ****   Build enterprise information systems:                     ****"
        $stderr.puts "   ****   Use Qworum in your information system, and enjoy the      ****"
        $stderr.puts "   ****   benefits of a powerful SOA technology.                    ****"
        $stderr.puts "   ****                                                             ****"
        $stderr.puts "   ****   Learn more at http://www.qworum.com/                      ****"
        $stderr.puts "   *********************************************************************"
        $stderr.puts ""
end

$stderr.puts "End of podcatching session." if opt.verbose