#!/usr/bin/env ruby
$:.unshift('vendor/ruby-mediawiki/lib')
require 'mediawiki/dotfile'
require 'cgi'
require 'date'
require 'erb'
require 'net/http'

#----------------------------------------------------------------------------
# Constants

RFC822 = "%a, %d %b %Y %T %z" # for Date::strftime
require "#{$0}.templates.rb"

#----------------------------------------------------------------------------
# Some helper functions

def parse_template(title, template)
  template_re = Regexp.new("\\\{\\\{" + template + "(.*?)\\\}\\\}")

  fields = {}

  fields_string = @wiki.article(title).text.scan(template_re)[0][0]

  inlink = 0
  field = ""
  fields_string += "|" unless fields_string.match(/\|$/)
  fields_string.split(//).each do |c|
    if c == "|" && inlink == 0
      (key, value) = field.split(/=/)
      fields[key] = value
      field = ""
    else
      inlink += 1 if c == "["
      inlink -= 1 if c == "]"
      field += c
    end
  end

  fields
end

def datum2isodate(datum)
  return datum[6..9] + "-" + datum[3..4] + "-" + datum[0..1]
end

def head(url)
  uri = URI.parse(url)
 
  Net::HTTP.start(uri.host, uri.port) do |http|
    http.head(uri.path)
  end
end

#----------------------------------------------------------------------------
# Get episodes from wiki

@wiki = MediaWiki.dotfile(nil,'entropia')

template = "Vorlage:Radio Chaotica-Sendung"
episodes = []
@wiki.article(template).what_links_here.each do |page|
  # puts page # DEBUG
  if erste_sendung = parse_template(page, template)["erste_sendung"]
    episode = {
      "title"         => page,
      "url"           => @wiki.full_article_url(page),
      "discussion"    => @wiki.full_article_url("Diskussion:#{page}"),
      "enclosure_url" => parse_template(page, template)["download"],
      "date"          => Date.today(), # fallback
    } 
    

    # Get a real date
    erste_sendung.gsub!(/\s*um\s*\d+:\d+$/,"")
    if erste_sendung !~ /^[0-9]{2}\.[0-9]{2}\.[0-9]{4}.*$/
      $stderr.puts "Field '#{erste_sendung}' in #{episode["url"]} looks funny, fall back to today."
    else
      episode["date"] = Date.parse(datum2isodate(erste_sendung))
    end
    episode["pubdate"] = episode["date"].strftime(RFC822)
  
 
    # Get content type and length
    head = head(episode["enclosure_url"])
    episode["length"] = head["content-length"]
    episode["type"]   = head["content-type"]

    # We just assume that the episode's length is an hour or so
    episode["duration"] = "00:59:59"

    episodes.push(episode)
  end
  $stderr.puts "DEBUG: Only crawling one episode"; break 
end

# Sort episodes, starting with last
episodes = episodes.sort do |x,y| 
  y["date"] <=> x["date"]
end

#----------------------------------------------------------------------------
# Generate RSS

items = ""
episodes.each do |episode|
  items += ERB.new(TPL_ITEM).result(binding);
end

rss = ERB.new(TPL_RSS).result;
#puts rss #DEBUG

rssfile = File.new("/home/neingeist/public_html/chaotica.xml", "w")
rssfile.puts rss
rssfile.close