#!/opt/local/bin/ruby

# $Id$
# $URL$

#
# Copyright (c) 2006 Ward Wouts <ward@wouts.nl>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#

########################################
# the configuration bit

@podcasts = {
	# the podcast name
	"distortedview" => {
		# where's the rss file
		"rss" => 'http://www.distortedview.com/show/index.xml',
		# where should enclosures be saved
		"savedir" => '/Users/ward/Private/mp3/[books]/Distorted View',
		# rename magic, this is used on the file name with sub!
		"rename" => [ /_(\d\d\d\d)(\d\d)/, '\2\1' ],
		# directory to put symlinks to the new files
		"linkdir" => '/Users/ward/ipod_sync/[books]/Distorted View',
	},
	"tagesschau" => {
		"rss" => 'http://www.tagesschau.de/export/podcast',
		"savedir" => '/Users/ward/ipod_sync/[books]/Tagesschau',
		# delete files that aren't in the rss anylonger
		"delete" => true,
	},
}

########################################
# code from here on

require 'net/http'
require 'uri'
require 'rexml/document'

def fetch(uri_str, limit = 10)
	# You should choose better exception.
	raise ArgumentError, 'HTTP redirect too deep' if limit == 0

	response = Net::HTTP.get_response(URI.parse(uri_str))
	case response
	when Net::HTTPSuccess		then response
	when Net::HTTPRedirection	then fetch(response['location'], limit - 1)
	else
		response.error!
	end
end

def deleteold(podcast)
	Dir.open(@podcasts[podcast]["savedir"]).each {|entry|
		if File.file?("#{@podcasts[podcast]["savedir"]}/#{entry}") &&
		    ! @filelist[entry]
			puts "  deleting #{entry}"
			File.unlink("#{@podcasts[podcast]["savedir"]}/#{entry}")
		end
	}
end

def getenclosure(podcast, enclosure)
	if ! enclosure.attribute("url").nil?
		cast = enclosure.attribute("url").to_s.dup
		filename = cast.dup
		filename.sub!(/^.*\//, "")
		if @podcasts[podcast]["rename"]
			filename.sub!(@podcasts[podcast]["rename"][0], @podcasts[podcast]["rename"][1])
		end
		@filelist[filename] = true
		if ! File.exists?("#{@podcasts[podcast]["savedir"]}/#{filename}")
			puts "  getting #{@podcasts[podcast]["savedir"]}/#{filename}"
			response = fetch(cast)
			File.open("#{@podcasts[podcast]["savedir"]}/#{filename}", "w"){|f|
				f.print(response.body)
			}
			if @podcasts[podcast]["linkdir"]
				File.symlink("#{@podcasts[podcast]["savedir"]}/#{filename}", "#{@podcasts[podcast]["linkdir"]}/#{filename}")
			end
		end
	end
end

for podcast in @podcasts.keys.sort
	puts podcast
	res = fetch(@podcasts[podcast]["rss"])
	@filelist = {}

	xmldoc = REXML::Document.new(res.body)
	xmldoc.elements.each("rss/channel/*/enclosure") {|enclosure|
		getenclosure(podcast, enclosure)
	}
	if @podcasts[podcast]["delete"]
		deleteold(podcast)
	end
end