# Weather plugin for rbot
#
# NOAA National Weather Service support by MrChucho (mrchucho@mrchucho.net)
# Copyright (C) 2006 Ralph M. Churchill
#
# Weather Undeground support by Giuseppe "Oblomov" Bilotta <giuseppe.bilotta@gmail.com>
# Copyright (C) 2006 Giuseppe Bilotta

require 'uri'
require 'rexml/document'

# Wraps NOAA National Weather Service information
class CurrentConditions
    def initialize(station)
        @station = station
        @url = "http://www.nws.noaa.gov/data/current_obs/#{@station.upcase}.xml"
        @etag = String.new
        @mtime = Time.mktime(0)
        @current_conditions = String.new
        @iscached = false
    end
    def update
        begin
            open(@url,"If-Modified-Since" => @mtime.rfc2822) do |feed|
            # open(@url,"If-None-Match"=>@etag) do |feed|
                @etag = feed.meta['etag']
                @mtime = feed.last_modified
                cc_doc = (REXML::Document.new feed).root
                @iscached = false
                @current_conditions = parse(cc_doc)
            end
        rescue OpenURI::HTTPError => e
            case e
            when /304/:
                @iscached = true
            when /404/:
                raise "Data for #{@station} not found"
            else
                raise "Error retrieving data: #{e}"
            end
        end
        @current_conditions # +" Cached? "+ ((@iscached) ? "Y" : "N")
    end
    def parse(cc_doc)
        cc = Hash.new
        cc_doc.elements.each do |c|
            cc[c.name.to_sym] = c.text
        end
        "At #{cc[:observation_time_rfc822]}, the wind was #{cc[:wind_string]} at #{cc[:location]} (#{cc[:station_id]}). The temperature was #{cc[:temperature_string]}#{heat_index_or_wind_chill(cc)}, and the pressure was #{cc[:pressure_string]}. The relative humidity was #{cc[:relative_humidity]}%. Current conditions are #{cc[:weather]} with #{cc[:visibility_mi]}mi visibility."
    end
private
    def heat_index_or_wind_chill(cc)
        hi = cc[:heat_index_string]
        wc = cc[:windchill_string]
        if hi != 'NA' then
            " with a heat index of #{hi}"
        elsif wc != 'NA' then
            " with a windchill of #{wc}"
        else
            ""
        end
    end
end

class WeatherPlugin < Plugin
  
  def help(plugin, topic="")
    case topic
    when "nws"
      "weather nws <station> => display the current conditions at the location specified by the NOAA National Weather Service station code <station> ( lookup your station code at http://www.nws.noaa.gov/data/current_obs/ )"
    when "station", "wu"
      "weather <location> => display the current conditions at the location specified, looking it up on the Weather Underground site; you can use 'station <code>' to look up data by station code ( lookup your station code at http://www.weatherunderground.com/ )" 
    else
      "weather information lookup. Looks up weather information for the last location you specified. See topics 'nws' and 'wu' for more information"
    end
  end
  
  def initialize
    super

    @nws_cache = Hash.new

    @wu_url="http://mobile.wunderground.com/cgi-bin/findweather/getForecast?brand=mobile&query=%s"
    @wu_station_url="http://mobile.wunderground.com/global/stations/%s.html"
  end
  
  def weather(m, params)
    loc = nil
    service = nil
    if params[:where].empty?
      if @registry.has_key?(m.sourcenick)
        where = @registry[m.sourcenick]
        debug "Loaded weather info #{where.inspect} for #{m.sourcenick}"
        save = false
      else
        debug "No weather info for #{m.sourcenick}"
        m.reply "I don't know where you are yet, #{m.sourcenick}. See 'help weather nws' or 'help weather wu' for additional help"
        return
      end
    else
      where = params[:where]
      save = true
      unless ['nws','station'].include?(where.first)
        loc = where.to_s
        service = :wu
      end
    end
    unless service
      loc = where[1].to_s
      service = where.first.to_sym
    end
    if loc.empty?
      debug "No weather location found for #{m.sourcenick}"
      m.reply "I don't know where you are yet, #{m.sourcenick}. See 'help weather nws' or 'help weather wu' for additional help"
    end
    case service
    when :nws
      nws_describe(m, loc)
    when :station
      wu_station(m, loc)
    when :wu
      wu_weather(m, loc)
    end
    @registry[m.sourcenick] = [service, loc] if save
  end

  def nws_describe(m, where)
    if @nws_cache.has_key?(where) then
        met = @nws_cache[where]
    else
        met = CurrentConditions.new(where)
    end
    if met
      begin
        m.reply met.update
        @nws_cache[where] = met
      rescue => e
        m.reply e.message
      end
    else
      m.reply "couldn't find weather data for #{where}"
    end
  end

  def wu_station(m, where)
    begin
      xml = @bot.httputil.get_cached(@wu_station_url % URI.escape(where))
      case xml
      when nil
        m.reply "couldn't retrieve weather information, sorry"
        return
      when /<table border.*?>(.*?)<\/table>/m
        data = $1
        m.reply wu_weather_filter(data)
      else
        debug xml
        m.reply "something went wrong with the data for #{where}..."
      end
    rescue => e
      m.reply "retrieving info about '#{where}' failed (#{e})"
    end
  end

  def wu_weather(m, where)
    begin
      xml = @bot.httputil.get_cached(@wu_url % URI.escape(where))
      case xml
      when nil
        m.reply "couldn't retrieve weather information, sorry"
        return
      when /City Not Found/
        m.reply "no such location found (#{where})"
        return
      when /<table border.*?>(.*?)<\/table>/m
        data = $1
        m.reply wu_weather_filter(data)
      when /<a href="\/global\/stations\//
        stations = xml.scan(/<a href="\/global\/stations\/(.*?)\.html">/)
        m.reply "multiple stations available, use 'weather station <code>' where code is one of " + stations.join(", ")
      else
        debug xml
        m.reply "something went wrong with the data from #{where}..."
      end
    rescue => e
      m.reply "retrieving info about '#{where}' failed (#{e})"
    end
  end

  def wu_weather_filter(stuff)
    txt = stuff
    txt.gsub!(/[\n\s]+/,' ')
    data = Hash.new
    txt.gsub!(/&nbsp;/, ' ')
    txt.gsub!(/&#176;/, ' ') # degree sign
    txt.gsub!(/<\/?b>/,'')
    txt.gsub!(/<\/?span[^<>]*?>/,'')
    txt.gsub!(/<img\s*[^<>]*?>/,'')
    txt.gsub!(/<br\s?\/?>/,'')

    result = Array.new
    if txt.match(/<\/a>\s*Updated:\s*(.*?)\s*Observed at\s*(.*?)\s*<\/td>/)
      result << ("Weather info for %s (updated on %s)" % [$2, $1])
    end
    txt.scan(/<tr>\s*<td>\s*(.*?)\s*<\/td>\s*<td>\s*(.*?)\s*<\/td>\s*<\/tr>/) { |k, v|
      unless v.empty? or v == "-" or k =="Raw METAR"
        result << ("%s: %s" % [k, v])
      end
    }
    return result.join('; ')
  end
end

plugin = WeatherPlugin.new
plugin.map 'weather *where', :defaults => {:where => false}