# hatena_bookmark.rb $Id$
#
# usage:
#   <%=hatena_bookmark%>
#
# Copyright (c) 2005 MATSUOKA Kohei <kohei@machu.jp>
# Distributed under the GPL
#
require 'xmlrpc/client'
require 'pstore'
require 'open-uri'
require 'rss/1.0'
require 'kconv'

class HatenaBookmark
  def initialize(base_url, options = {})
    options[:sort]       ||= 'hot' # eid|hot|count
    options[:threshold]  ||= 5
    options[:cache_file] ||= 'cache_rss.xml'
    options[:cache_time] ||= 60    # minutes
    options[:max_item]   ||= 5
    @items = get_items(base_url, options)
  end

  def each(&block)
    @items.each(&block)
  end

  private

  def get_items(base_url, options)
    items = []
    hatena_open(base_url, options) do |f|
      rss = RSS::Parser.parse(f)
      comments = get_comment_count(rss.items.map {|item| item.about })
      rss.items.each do |item|
        items.push({
          :url => item.about,
          :title => item.title.strip.toeuc,
          :comment => comments[item.about]
        })
      end
    end
    options[:max_item] > 0 ? items[0...options[:max_item]] : items
  end

  def get_comment_count(urls)
    # STDERR.puts 'get count'
    begin
      server = XMLRPC::Client.new('b.hatena.ne.jp', '/xmlrpc')
      server.call('bookmark.getCount', *urls)
    rescue XMLRPC::FaultException => e
      # STDERR.puts "Error: (#{e.faultCode}) #{e.faultString}", $@.join("\n")
      {}
    end
  end

  def hatena_open(base_url, options, &block)
    unless File.exist?(options[:cache_file]) && File.atime(options[:cache_file]) + options[:cache_time] * 60 > Time.now
      # STDERR.puts 'get RSS'
      rss_url = 'http://b.hatena.ne.jp/entrylist?mode=rss&url='
      rss_url << URI.escape(base_url.untaint, /[^a-zA-Z._~]/n)
      rss_url << "&sort=#{options[:sort]}&threshold=#{options[:threshold]}"
      open(options[:cache_file], 'w') {|fout|
        open(rss_url).each {|line| fout.puts line }
      }
    end
    open(options[:cache_file], &block)
  end
end

def shorten(body, length = 120)
    matched = body.gsub(/\n/, ' ').scan(/^.{0,#{length - 2}}/)[0]
    $'.empty? ? matched : matched + '..'
end

def hatena_bookmark
  cache_dir = "#{@cache_path}/hatena"
  Dir::mkdir(cache_dir) unless File::directory?(cache_dir)
  cache_file = "#{cache_dir}/bookmark.dat"
  cache_time = 1 * 60 * 60  # 1 hour

  body = nil
  PStore.new(cache_file).transaction do |db|
    # STDERR.puts db['expire']
    if db['body'] && db['expire'] && db['expire'] > Time.now
      # STDERR.puts 'use cache'
      body = db['body']
      db.abort
    else
      bookmark = HatenaBookmark.new(@conf.base_url, {:cache_file => "#{cache_dir}/cache-rss.xml"})
      body = %Q|<ul class="recent-list">\n|
      body << %Q|\t<li><a href="http://b.hatena.ne.jp/entrylist?url=#{@conf.base_url}&sort=hot">Hatena Bookmark</a>\n|
      body << %Q|\t<ul class="recent-list-item">\n|
      bookmark.each do |b|
        body << %Q|\t\t<li><a href="#{b[:url]}" title="#{b[:title]}">|
        body << %Q|#{shorten(b[:title].gsub(/( - )?#{@conf.html_title}( - )?/, ''), 18)}</a> |
        body << %Q|<a href="http://b.hatena.ne.jp/entry/#{URI.escape(b[:url])}">(#{b[:comment]})</a></li>\n|
      end
      body << %Q|\t</ul>\n\t</li>\n|
      body << %Q|</ul>|
      db['body'] = body
      db['expire'] = Time.now + cache_time
      db.commit
    end
  end
  body
end