Mikubot/bot/bot.lua

  http = require("socket.http")
  URL = require("socket.url")
  json = (loadfile "./bot/JSON.lua")()

  VERSION = 'v0.6'

  function on_msg_receive (msg)

    if msg_valid(msg) == false then
      return
    end
    -- Check if command starts with ! eg !echo
    if msg.text:sub(0,1) == '!' then
      do_action(msg)
    else
      if is_image_url(msg.text) then
        send_image_from_url (msg)
      elseif get_youtube_code(msg.text) then
        send_youtube_thumbnail(msg)
      else
        if is_file_url(msg.text) then
          send_file_from_url(msg)
        end
      end
    end

    mark_read(get_receiver(msg), ok_cb, false)
    -- write_log_file(msg)
  end


  function ok_cb(extra, success, result)
  end

  function msg_valid(msg)
     if msg.out then
        return false
     end
     if msg.date < now then
       return false
     end
     if msg.text == nil then
        return false
     end
     if msg.unread == 0 then
        return false
     end
  end

  function send_file_from_url (msg)
    last = string.get_last_word(msg.text)
    file = download_to_file(last)
    send_document(get_receiver(msg), file, ok_cb, false)
  end

  function send_image_from_url (msg)
    last = string.get_last_word(msg.text)
    file = download_to_file(last)
    send_photo(get_receiver(msg), file, ok_cb, false)
  end

  function is_image_url(text)
    last = string.get_last_word(text)
    extension = string.get_extension_from_filename(last) -- TODO:  Change it please
    if extension == 'jpg' or extension == 'png' or extension == 'jpeg' then
      return true
    end
    return false
  end

  function get_youtube_code( text )
    local yt_normal = string.match(text, "youtube.com/watch%?v=([A-Za-z0-9-]+)")
    if yt_normal then
      return yt_normal
    end
    yt_short = string.match(text, "youtu.be/([A-Za-z0-9-]+)")
    if yt_short then
      return yt_short
    end
    return false
  end

  function send_youtube_thumbnail(msg)
    yt_code = get_youtube_code(msg.text)
    yt_thumbnail = "http://img.youtube.com/vi/".. yt_code .."/hqdefault.jpg"
    file = download_to_file(yt_thumbnail)
    send_photo(get_receiver(msg), file, ok_cb, false)
  end

  function is_file_url(text)
    last = string.get_last_word(text)
    extension = string.get_extension_from_filename(last)
    if extension == 'gif' then
      return true
    end
    return false
  end

  -- Where magic happens
  function do_action(msg)
     local receiver = get_receiver(msg)

     if string.starts(msg.text, '!sh') then
        text = run_sh(msg)
        send_msg(receiver, text, ok_cb, false)
        return
     end
    
     if string.starts(msg.text, '!uc3m') then
        text = get_fortunes_uc3m()
        send_msg(receiver, text, ok_cb, false)
        return
     end 

     if string.starts(msg.text, '!img') then
        text = msg.text:sub(6,-1)
        url = getGoogleImage(text)
        file_path = download_to_file(url)
        print(file_path)
        send_photo(receiver, file_path, ok_cb, false)
        return
     end

    if string.starts(msg.text, '!rae') then
      text = msg.text:sub(6,-1)
      meaning = getDulcinea(text)
      send_msg(receiver, meaning, ok_cb, false)
    end
    
    if string.starts(msg.text, '!9gag') then
      url, title = get_9GAG()
      file_path = download_to_file(url)
      send_photo(receiver, file_path, ok_cb, false)
      send_msg(receiver, title, ok_cb, false)
      return
    end 

     if string.starts(msg.text, '!fortune') then
        text = run_bash('fortune')
        send_msg(receiver, text, ok_cb, false)
        return
     end 

     if string.starts(msg.text, '!forni') then
        text = msg.text:sub(8,-1)
        send_msg('Fornicio_2.0', text, ok_cb, false)
        return
     end 

     if string.starts(msg.text, '!fwd') then
        fwd_msg (receiver, msg.id, ok_cb, false)
        return
     end 

     if string.starts(msg.text, '!cpu') then
        text = run_bash('uname -snr') .. ' ' .. run_bash('whoami')
        text = text .. '\n' .. run_bash('top -b |head -2')
        send_msg(receiver, text, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!ping') then
        print('receiver: '..receiver)
        send_msg (receiver, 'pong', ok_cb, false)
        return
     end

     if string.starts(msg.text, '!weather') then
        if string.len(msg.text) <= 9 then
           city = 'Madrid,ES'
        else  
           city = msg.text:sub(10,-1)
        end    
        text = get_weather(city)
        send_msg(receiver, text, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!echo') then
        echo = msg.text:sub(7,-1)
        send_msg(receiver, echo, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!eur') then
        local eur = getEURUSD(msg.text)
        send_msg(receiver, eur, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!set') then
        local text = save_value(msg.text:sub(5,-1))
        send_msg(receiver, text, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!get') then
        local text = get_value(msg.text:sub(6,-1))
        send_msg(receiver, text, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!version') then
        text = 'James Bot '.. VERSION .. [[ 
  Licencia GNU v2, código disponible en http://git.io/6jdjGg

  Al Bot le gusta la gente solidaria. 
  Puedes hacer una donación a la ONG que decidas y ayudar a otras personas.]]
        send_msg(receiver, text, ok_cb, false)
        return
     end

     if string.starts(msg.text, '!help') then
        text = [[!help : print this help 
  !ping : bot sends pong 
  !sh (text) : send commands to bash (only privileged users)
  !echo (text) : echo the msg 
  !version : version info
  !cpu : status (uname + top)
  !fwd : forward msg
  !forni : send text to group Fornicio
  !fortune : print a random adage
  !weather [city] : weather in that city (Madrid if not city)
  !9gag : send random url image from 9gag
  !rae (word): Spanish dictionary
  !eur : EURUSD market value
  !img (text) : search image with Google API and sends it
  !uc3m : fortunes from Universidad Carlos III
  !set [variable_name] [value] store for !get
  !get (variable_name) retrieves variables saved with !set]]
        send_msg(receiver, text, ok_cb, false)
        return
     end

  end

  function string.starts(String,Start)
     return string.sub(String,1,string.len(Start))==Start
  end

  function load_config()
     local f = assert(io.open('./bot/config.json', "r"))
     local c = f:read "*a"
     local config = json:decode(c)
     if config.sh_enabled then 
        print ("!sh command is enabled")
        for v,user in pairs(config.sudo_users) do
           print("Allowed user: " .. user)
        end
     end
     -- print("Torrent path: " .. config.torrent_path)
     f:close()
     return config
  end

  function save_value( text )
    var_name, var_value = string.match(text, "(%a+) (.+)")
    if (a == nil or b == nil) then
      return "Usage: !set var_name value"
    end
    config.values[var_name] = var_value
    local json_text = json:encode_pretty(config) 
    file = io.open ("./bot/config.json", "w+")
    file:write(json_text)
    file:close()
    return "Saved "..var_name.." = "..var_value
  end

  function get_value( value_name )
    -- If there is not value name, return all the values.
    if (value_name == "" ) then
      local text = ""
      for key,value in pairs(config.values) do
        text = text..key.." = "..value.."\n"
      end
      return text
    end 
    local value = config.values[value_name]
    if ( value == nil) then
      return "Cant find "..value_name
    end
    return value_name.." = "..value
  end

  function is_sudo(msg)
     local var = false
     -- Check users id in config 
     for v,user in pairs(config.sudo_users) do 
        if user == msg.from.id then 
           var = true 
        end
     end
     return var
  end

  function write_log_file(msg)
    name = get_name(msg)
    ret = name .. ' > ' .. msg.text
    write_to_file(config.log_file, ret)
  end

  -- Saves a string to file
  function write_to_file(filename, value)
    if (value) then
      local file = io.open(filename,"a")
      file:write(value, "\n")
      file:close()
    end
  end

  function get_name(msg)
     local name = msg.from.first_name
     if name == nil then
        name = msg.from.id
     end
     return name
  end

  function run_sh(msg)
     name = get_name(msg)
     text = ''
     if config.sh_enabled == false then 
        text = '!sh command is disabled'
     else
        if is_sudo(msg) then
           bash = msg.text:sub(4,-1)
           text = run_bash(bash)
        else
           text = name .. ' you have no power here!'
        end
     end
     return text
  end

  function run_bash(str)
    local cmd = io.popen(str)
    local result = cmd:read('*all')
    cmd:close()
    return result
  end

  function get_fortunes_uc3m()
     math.randomseed(os.time())
     local i = math.random(0,178) -- max 178
     local web = "http://www.gul.es/fortunes/f"..i 
     b, c, h = http.request(web)
     return b
  end

  function getDulcinea( text )
    -- Powered by https://github.com/javierhonduco/dulcinea
    local api = "http://dulcinea.herokuapp.com/api/?query="
    b = http.request(api..text)
    dulcinea = json:decode(b)
    if dulcinea.status == "error" then
      return "Error: " .. dulcinea.message
    end
    while dulcinea.type == "multiple" do
      text = dulcinea.response[1].id
      b = http.request(api..text)
      dulcinea = json:decode(b)
    end
    vardump(dulcinea)
    local text = ""
    local responses = #dulcinea.response
    if (responses > 5) then
      responses = 5
    end
    for i = 1, responses, 1 do 
      text = text .. dulcinea.response[i].word .. "\n"
      local meanings = #dulcinea.response[i].meanings
      if (meanings > 5) then
        meanings = 5
      end
      for j = 1, meanings, 1 do
        local meaning = dulcinea.response[i].meanings[j].meaning 
        text = text .. meaning .. "\n\n"
      end
    end
    return text

  end

  function getGoogleImage(text)
    text = URL.escape(text)
    for i = 1, 5, 1 do -- Try 5 times
      local api = "https://ajax.googleapis.com/ajax/services/search/images?v=1.0&rsz=8&q="
      b = http.request(api..text)
      local google = json:decode(b)

      if (google.responseStatus == 200) then -- OK
        math.randomseed(os.time())
        i = math.random(#google.responseData.results) -- Random image from results
        return google.responseData.results[i].url
      end
    end
  end

  function get_9GAG()
     b = http.request("http://api-9gag.herokuapp.com/")
     local gag = json:decode(b)
     math.randomseed(os.time())
     i = math.random(#gag) -- random max json table size (# is an operator o.O)
     local link_image = gag[i].src
     local title = gag[i].title
     if link_image:sub(0,2) == '//' then
        link_image = msg.text:sub(3,-1)
     end
     return link_image, title
  end

  function getEURUSD(text)
    b = http.request("http://webrates.truefx.com/rates/connect.html?c=EUR/USD&f=csv&s=n")
    local rates = b:split(", ")
    local symbol = rates[1]
    local timestamp = rates[2]
    local sell = rates[3]..rates[4]
    local buy = rates[5]..rates[6] 
    local usd =  string.match(text, "!eur (%d+[%d%.]*)")
    text = symbol..'\n'..'Buy: '..buy..'\n'..'Sell: '..sell
    if usd then
      eur = tonumber(usd) / tonumber(buy)
      text = text.."\n "..usd.."USD = "..eur.."EUR"
    end
    return text
  end


  function download_to_file( url )
    print("url a descargar: "..url)
    req, c, h = http.request(url)
    htype = h["content-type"]
    vardump(c)
    print("content-type: "..htype)
    if htype == "image/jpeg" then
      file_name = string.random(5)..".jpg"
      file_path = "/tmp/"..file_name
    else
      if htype == "image/gif" then
        file_name = string.random(5)..".gif"
        file_path = "/tmp/"..file_name
      else
        if htype == "image/png" then
          file_name = string.random(5)..".png"
          file_path = "/tmp/"..file_name
        else
          file_name = url:match("([^/]+)$")
          file_path = "/tmp/"..file_name
        end
      end
    end
    file = io.open(file_path, "w+")
    file:write(req)
    file:close()
    return file_path
  end

  function get_weather(location)
     b, c, h = http.request("http://api.openweathermap.org/data/2.5/weather?q=" .. location .. "&units=metric")
     weather = json:decode(b)
     local city = weather.name
     local country = weather.sys.country
     temp = 'The temperature in ' .. city .. ' (' .. country .. ')'
     temp = temp .. ' is ' .. weather.main.temp .. '°C'
     conditions = 'Current conditions are: ' .. weather.weather[1].description
     if weather.weather[1].main == 'Clear' then
  	  conditions = conditions .. ' ☀'
     elseif weather.weather[1].main == 'Clouds' then
  	  conditions = conditions .. ' ☁☁'
     elseif weather.weather[1].main == 'Rain' then
  	  conditions = conditions .. ' ☔'
     elseif weather.weather[1].main == 'Thunderstorm' then
  	  conditions = conditions .. ' ☔☔☔☔'
     end
     return temp .. '\n' .. conditions
  end

  function string.random(length)
     math.randomseed(os.time())
     local str = "";
     for i = 1, length do
        math.random(97, 122)
        str = str..string.char(math.random(97, 122));
     end
     return str;
  end

  function string.get_extension_from_filename( filename )
    return filename:match( "%.([^%.]+)$" )
  end

  function string.get_last_word( words )
    local splitted = split_by_space ( words )
    return splitted[#splitted]
  end

  function split_by_space ( text )
    words = {}
    for word in string.gmatch(text, "[^%s]+") do
       table.insert(words, word) 
    end
    return words
  end

  function string:split(sep)
    local sep, fields = sep or ":", {}
    local pattern = string.format("([^%s]+)", sep)
    self:gsub(pattern, function(c) fields[#fields+1] = c end)
    return fields
  end

  function vardump(value, depth, key)
    local linePrefix = ""
    local spaces = ""
    
    if key ~= nil then
      linePrefix = "["..key.."] = "
    end
    
    if depth == nil then
      depth = 0
    else
      depth = depth + 1
      for i=1, depth do spaces = spaces .. "  " end
    end
    
    if type(value) == 'table' then
      mTable = getmetatable(value)
      if mTable == nil then
        print(spaces ..linePrefix.."(table) ")
      else
        print(spaces .."(metatable) ")
          value = mTable
      end		
      for tableKey, tableValue in pairs(value) do
        vardump(tableValue, depth, tableKey)
      end
    elseif type(value)	== 'function' or 
        type(value)	== 'thread' or 
        type(value)	== 'userdata' or
        value		== nil
    then
      print(spaces..tostring(value))
    else
      print(spaces..linePrefix.."("..type(value)..") "..tostring(value))
    end
  end

  -- Start and load values
  config = load_config()
  our_id = 0
  now = os.time()

  function get_receiver(msg)
    if msg.to.type == 'user' then
      return 'user#id'..msg.from.id
    end
    if msg.to.type == 'chat' then
      return 'chat#id'..msg.to.id
    end
  end


  function on_our_id (id)
    our_id = id
  end

  function on_user_update (user, what)
    --vardump (user)
  end

  function on_chat_update (chat, what)
    --vardump (chat)
  end

  function on_secret_chat_update (schat, what)
    --vardump (schat)
  end

  function on_get_difference_end ()
  end

  function on_binlog_replay_end ()
    started = 1
  end