#!/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',
		# option to write an m3u file after fetching the mp3s
		"m3u" => '/Users/ward/dv.m3u',
	},
#	"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,
#	},
#	"pennradio" => {
#		"rss" => 'http://penn.freefm.com/pages/podcast/431.rss',
#		# %%DATE%% is a magic word here, gets replaced by the pubdate in
#		# YYYYMMDD format. Won't work if there is no pubDate in the rss feed
#		"rename" => [ /^/, '%%DATE%%-' ],
#		"savedir" => '/Users/ward/Private/mp3/[books]/PennRadio',
#		"linkdir" => '/Users/ward/ipod_sync/[books]/PennRadio',
#	},
	"bsdtalk" => {
		"rss" => 'http://feeds.feedburner.com/Bsdtalk',
		"savedir" => '/Users/ward/Private/mp3/[books]/BSDTalk',
		"linkdir" => '/Users/ward/ipod_sync/[books]/BSDTalk',
	},
}

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

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

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, item)
	enclosure = nil
	item.each_element{|x|
		if x.name == "enclosure"
			enclosure = x
		end
	}
	pubdate = item.get_elements("pubDate")[0]
	date = nil
	if ! pubdate.nil?
		date = Date.parse(pubdate.text).strftime("%Y%m%d")
	end
	if ! enclosure.nil? && ! enclosure.attribute("url").nil?
		cast = enclosure.attribute("url").to_s.dup
		filename = cast.dup
		filename.sub!(/^.*\//, "")
		if @podcasts[podcast]["rename"]
			replacement = @podcasts[podcast]["rename"][1].dup
			if replacement.match(/%%DATE%%/)
				replacement.sub!(/%%DATE%%/, date)
			end
			filename.sub!(@podcasts[podcast]["rename"][0], replacement)
		end
		@filelist[filename] = true
		if ! File.exists?("#{@podcasts[podcast]["savedir"]}/#{filename}")
			puts "  getting #{@podcasts[podcast]["savedir"]}/#{filename}"
			begin
				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
				return "#{@podcasts[podcast]["savedir"]}/#{filename}"
			rescue Timeout::Error, Errno::EHOSTUNREACH, Errno::ECONNREFUSED, Errno::ECONNRESET, Errno::ETIMEDOUT, Net::HTTPFatalError
				puts "	error #{$!} fetching, skipping"
			end
		else
			return "#{@podcasts[podcast]["savedir"]}/#{filename}"
		end
	end
end

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

#		body.gsub!(/#{13.chr}#{10.chr}/, "#{10.chr}")
		xmldoc = REXML::Document.new(res.body)
		xmldoc.elements.each("rss/channel") {|item|
			item.each_element{|x|
				if x.name == "item"
					files.push getenclosure(podcast, x)
				end
			}
		}
		if @podcasts[podcast]["delete"]
			deleteold(podcast)
		end
		if @podcasts[podcast]["m3u"]
			File.open(@podcasts[podcast]["m3u"], "w"){|f|
				files.each{|file|
					f.puts file
				}
			}
		end
	rescue
		rescue Timeout::Error, Errno::EHOSTUNREACH, Errno::ECONNREFUSED, Errno::ECONNRESET, Errno::ETIMEDOUT, Net::HTTPFatalError
			puts "	error #{$!} fetching, skipping"
	end
end