#!/usr/bin/env ruby

# $Id$
# $URL$

#
# Copyright (c) 2006-2007 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.
#

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

def usage
	puts <<EOT
Usage: #{$0.sub(/.*\//, "")} [options]

-c, --configfile <file>		use configuration from <file> (default $HOME/.getdistortedrc)
-h, --help			show this message
-l, --list			list podcasts
-p, --podcast <podcast>		only fetch <podcast>
-v, --verbose			be more verbose
EOT
	exit
end

def cmdline
	options = Hash.new
	begin
		opts = GetoptLong.new(
			[ "-c", "--configfile",		GetoptLong::REQUIRED_ARGUMENT ],
			[ "-h", "--help",		GetoptLong::NO_ARGUMENT ],
			[ "-l", "--list",		GetoptLong::NO_ARGUMENT ],
			[ "-p", "--podcast",		GetoptLong::REQUIRED_ARGUMENT ],
			[ "-v", "--verbose",		GetoptLong::NO_ARGUMENT ]
		)
		opts.quiet=true

		opts.each do |opt, arg|
			options[opt] = arg
		end

	rescue
		print "#{$!}\n"
		usage
	end
	if options["-h"]
		usage
	end
	if options["-v"]
		@verbose = true
	end
	return options
end

def verbose(msg)
	if @verbose
		puts msg
	end
end

def readconfig(configfile=nil)
	configfile = configfile.nil? ? "#{ENV['HOME']}/.getdistortedrc" : configfile
	load configfile
end

def listpodcasts
	for podcast in @podcasts.keys.sort
		puts podcast
	end
	exit
end

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

	verbose("Fetching #{uri_str}\n\n")

	host = URI.parse(uri_str).host
	path = URI.parse(uri_str).path
	query = URI.parse(uri_str).query

	proxy_host = nil
	proxy_port = nil
	proxy_user = nil
	proxy_pass = nil

	if ENV['HTTP_PROXY']
		uri = URI.parse(ENV['HTTP_PROXY'])
		proxy_host = uri.host
		proxy_port = uri.port
		proxy_user, proxy_pass = uri.userinfo.split(/:/) if uri.userinfo
	end

	Net::HTTP::Proxy(proxy_host, proxy_port,
		proxy_user, proxy_pass).start(host) {|http|
		if query
			req = Net::HTTP::Get.new("#{path}?#{query}")
		else
			req = Net::HTTP::Get.new("#{path}")
		end
		req.basic_auth @user, @pass
		response = http.request(req)
		case response
		when Net::HTTPSuccess		then response
		when Net::HTTPRedirection	then
			verbose("Redirecting to #{response['location']}")
			fetch(response['location'], limit - 1)
		when Net::HTTPNotFound		then puts "404 Not Found #{uri_str}"; response.error!
		when Net::HTTPUnauthorized	then puts "401 Authorization Required #{uri_str}"; response.error!
		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").value.to_s.dup
		filename = cast.dup
		filename.sub!(/^.*\//, "")
		if @podcasts[podcast]["rename"]
			replacement = @podcasts[podcast]["rename"][1].dup
			if replacement.match(/%%DATE%%/)
				replacement.gsub!(/%%DATE%%/, date)
			end
			filename.gsub!(@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

def getcasts(podcast=nil)
	worklist = Array.new
	if podcast.nil?
		worklist = @podcasts.keys.sort
	else
		worklist.push podcast
	end
	for podcast in worklist
		files = Array.new
		puts podcast
		begin
			@user = @podcasts[podcast]["username"].nil? ? nil : @podcasts[podcast]["username"]
			@pass = @podcasts[podcast]["password"].nil? ? nil : @podcasts[podcast]["password"]
			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"
						verbose("Item found:\n#{x}\n\n")
						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
end

@verbose = false
options = cmdline
readconfig
options["-l"].nil? || listpodcasts
if options["-p"].nil?
	getcasts
else
	getcasts(options["-p"])
end