require 'net/http'
require 'uri'
require 'cgi'

Url = Struct.new("Url", :channel, :nick, :time, :url)
TITLE_RE = /<\s*?title\s*?>(.+?)<\s*?\/title\s*?>/im

UNESCAPE_TABLE = {
    'raquo' => '>>',
    '#8220' => '"',
    '#8221' => '"',
    '#8212' => '--',
    '#39' => '\'',
    '#174' => '(R)',
    'micro' => 'u',
    '' => '',
    '' => '',
    '' => '',
    '' => '',
    #'' => '',
}

class UrlPlugin < Plugin
  BotConfig.register BotConfigIntegerValue.new('url.max_urls',
    :default => 100, :validate => Proc.new{|v| v > 0},
    :desc => "Maximum number of urls to store. New urls replace oldest ones.")
  BotConfig.register BotConfigBooleanValue.new('url.display_link_info',
    :default => true, 
    :desc => "Get the title of any links pasted to the channel and display it (also tells if the link is broken or the site is down)")
  
  def initialize
    super
    @registry.set_default(Array.new)
  end

  def help(plugin, topic="")
    "urls [<max>=4] => list <max> last urls mentioned in current channel, urls search [<max>=4] <regexp> => search for matching urls. In a private message, you must specify the channel to query, eg. urls <channel> [max], urls search <channel> [max] <regexp>"
  end

  def unescape_title(htmldata)
    # first pass -- let CGI try to attack it...
    htmldata = CGI::unescapeHTML htmldata
    
    # second pass -- destroy the remaining bits...
    htmldata.gsub(/(&(.+?);)/) {
        symbol = $2
        
        # remove the 0-paddng from unicode integers
        if symbol =~ /#(.+)/
            symbol = "##{$1.to_i.to_s}"
        end
        
        # output the symbol's irc-translated character, or a * if it's unknown
        UNESCAPE_TABLE[symbol] || '*'
    }
  end

  def get_title_from_html(pagedata)
    return unless TITLE_RE.match(pagedata)
    title = $1.strip.gsub(/\s*\n+\s*/, " ")
    title = unescape_title title
    title = title[0..255] if title.length > 255
    "[Link Info] title: #{title}"
  end

  def get_title_for_url(uri_str, depth=10)
    # This god-awful mess is what the ruby http library has reduced me to.
    # Python's HTTP lib is so much nicer. :~(
    
    if depth == 0
        raise "Error: Maximum redirects hit."
    end
    
    puts "+ Getting #{uri_str}"
    url = URI.parse(uri_str)
    return if url.scheme !~ /https?/
    
    puts "+ connecting to #{url.host}:#{url.port}"
    http = @bot.httputil.get_proxy(url) 
    title = http.start do |http|
      url.path = '/' if url.path == ''
      head = http.request_head(url.path)
      case head
        when Net::HTTPRedirection then
          # call self recursively if this is a redirect
          redirect_to = head['location']
          puts "+ redirect location: #{redirect_to}"
          url = URI.join url.to_s, redirect_to
          puts "+ whee, redirecting to #{url.to_s}!"
          title = get_title_for_url(url.to_s, depth-1)
        when Net::HTTPSuccess then
          if head['content-type'] =~ /^text\// and (not head['content-length'] or head['content-length'].to_i < 400000)
            # since the content is 'text/*' and is small enough to
            # be a webpage, retrieve the title from the page
            puts "+ getting #{url.request_uri}"
            response = http.request_get(url.request_uri)
            return get_title_from_html(response.body)
          else
            # content doesn't have title, just display info.
            size = head['content-length'].gsub(/(\d)(?=\d{3}+(?:\.|$))(\d{3}\..*)?/,'\1,\2')
            #lastmod = head['last-modified']
            return "[Link Info] type: #{head['content-type']}#{size ? ", size: #{size} bytes" : ""}"
          end
        when Net::HTTPClientError then
          return "[Link Info] Error getting link (#{head.code} - #{head.message})"
        when Net::HTTPServerError then
          return "[Link Info] Error getting link (#{head.code} - #{head.message})"
      end
    end
  rescue SocketError => e
    return "[Link Info] Error connecting to site (#{e.message})"
  end

  def listen(m)
    return unless m.kind_of?(PrivMessage)
    return if m.address?
    # TODO support multiple urls in one line
    if m.message =~ /(f|ht)tps?:\/\//
      if m.message =~ /((f|ht)tps?:\/\/.*?)(?:\s+|$)/
        urlstr = $1
        list = @registry[m.target]

        if @bot.config['url.display_link_info']
          debug "Getting title for #{urlstr}..."
          title = get_title_for_url urlstr
          if title
            m.reply title
            debug "Title found!"
          else
            debug "Title not found!"
          end        
        end
    
        # check to see if this url is already listed
        return if list.find {|u| u.url == urlstr }
        
        url = Url.new(m.target, m.sourcenick, Time.new, urlstr)
        debug "#{list.length} urls so far"
        if list.length > @bot.config['url.max_urls']
          list.pop
        end
        debug "storing url #{url.url}"
        list.unshift url
        debug "#{list.length} urls now"
        @registry[m.target] = list
      end
    end
  end

  def urls(m, params)
    channel = params[:channel] ? params[:channel] : m.target
    max = params[:limit].to_i
    max = 10 if max > 10
    max = 1 if max < 1
    list = @registry[channel]
    if list.empty?
      m.reply "no urls seen yet for channel #{channel}"
    else
      list[0..(max-1)].each do |url|
        m.reply "[#{url.time.strftime('%Y/%m/%d %H:%M:%S')}] <#{url.nick}> #{url.url}"
      end
    end
  end

  def search(m, params)
    channel = params[:channel] ? params[:channel] : m.target
    max = params[:limit].to_i
    string = params[:string]
    max = 10 if max > 10
    max = 1 if max < 1
    regex = Regexp.new(string, Regexp::IGNORECASE)
    list = @registry[channel].find_all {|url|
      regex.match(url.url) || regex.match(url.nick)
    }
    if list.empty?
      m.reply "no matches for channel #{channel}"
    else
      list[0..(max-1)].each do |url|
        m.reply "[#{url.time.strftime('%Y/%m/%d %H:%M:%S')}] <#{url.nick}> #{url.url}"
      end
    end
  end
end
plugin = UrlPlugin.new
plugin.map 'urls search :channel :limit :string', :action => 'search',
                          :defaults => {:limit => 4},
                          :requirements => {:limit => /^\d+$/},
                          :public => false
plugin.map 'urls search :limit :string', :action => 'search',
                          :defaults => {:limit => 4},
                          :requirements => {:limit => /^\d+$/},
                          :private => false
plugin.map 'urls :channel :limit', :defaults => {:limit => 4},
                          :requirements => {:limit => /^\d+$/},
                          :public => false
plugin.map 'urls :limit', :defaults => {:limit => 4},
                          :requirements => {:limit => /^\d+$/},
                          :private => false