#!/usr/bin/ruby -Ku

require 'rubygems'
require 'twitter'
# マニュアルはhttp://route477.net/w/?RubyTwitterJa

require 'time'
require 'uri'
require 'open-uri'

UNAME = "TeX_Eq"
PASSWD = "xxxxxxxxxxxxxxx"
CACHE_FNAME = 'texeq_cache.dat'

cache_data = {}

if FileTest::exist?(CACHE_FNAME) then
  open(CACHE_FNAME){|io|
    cache_data = Marshal::load(io.read)
  }
end

last_tweet_time = cache_data[:last_tweet_time] || (Time::now - 24 * 60 * 60)

httpauth = Twitter::HTTPAuth.new(UNAME, PASSWD)
client = Twitter::Base.new(httpauth)

replies = client.replies.sort{|a, b|
  # 最新順に念のため並べ替え
  Time::parse(b[:created_at]) <=> Time::parse(a[:created_at])
}

replies.each{|tweet|
  if Time::parse(tweet[:created_at]) <= last_tweet_time then break end
  target = tweet[:user][:screen_name]
  next unless tweet[:text] =~ /@#{UNAME} */i
  eq = $'
  prefix = $`
  next if prefix =~ /RT:/
  options = {}
  prefix.split(/ +/).each{|item|
    case item
      when 'RT'
        next
      when 'T'
        options['chf'] = 'bg,s,FFFFFF00'
      when /\d+(?:x\d+)?/
        options['chs'] = $&
    end
  }
  options_str = ''
  unless options.empty? then
    options.each{|k, v| options_str += "#{k}=#{v}&"}
  end
  eq_url = "http://chart.apis.google.com/chart?cht=tx&#{options_str}chl=#{URI::escape(eq, /[^-_.!~*'()a-zA-Z\d?@]/n)}"
  eq_url.gsub!(/%23/, '%2523')
  eq_url.gsub!(/%3B/, '%253B')
  eq_url.gsub!(/%2B/, '%252B')
  begin
    shorten_url = OpenURI::open_uri("http://is.gd/api.php?longurl=#{eq_url}").read
    p shorten_url
    client.update("@#{target} #{shorten_url}")
  rescue
    p $!
    p $@
  end
}

unless replies.empty? then
  cache_data[:last_tweet_time] = Time::parse(replies[0][:created_at]) 
end

File::open(CACHE_FNAME, 'w'){|io|
  io << Marshal::dump(cache_data)
}