http = require("socket.http")
https = require("ssl.https")
ltn12 = require "ltn12"
URL = require("socket.url")
feedparser = require ("feedparser")
json = (loadfile "./libs/JSON.lua")()
serpent = (loadfile "./libs/serpent.lua")()
mimetype = (loadfile "./libs/mimetype.lua")()
redis = (loadfile "./libs/redis.lua")()

http.TIMEOUT = 5

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
  if msg.to.type == 'encr_chat' then
    return msg.to.print_name
 end
end

function is_chat_msg( msg )
  if msg.to.type == 'chat' then
    return true
  end
  return false
end

function string.random(length)
   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: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

-- Removes spaces
function string.trim(s)
  return s:gsub("^%s*(.-)%s*$", "%1")
end

function get_http_file_name(url, headers)
  -- Eg: foo.var
  local file_name = url:match("[^%w]+([%.%w]+)$")
  -- Any delimited alphanumeric on the url
  file_name = file_name or url:match("[^%w]+(%w+)[^%w]+$")
  -- Random name, hope content-type works
  file_name = file_name or str:random(5)

  local content_type = headers["content-type"] 
  
  local extension = nil
  if content_type then
    extension = mimetype.get_mime_extension(content_type) 
  end

  if extension then
    file_name = file_name.."."..extension
  end
  
  local disposition = headers["content-disposition"]
  if disposition then
    -- attachment; filename=CodeCogsEqn.png
    file_name = disposition:match('filename=([^;]+)') or file_name
	file_name = string.gsub(file_name, "\"", "")
  end
  
  return file_name
end

--  Saves file to tmp/. If file_name isn't provided,
-- will get the text after the last "/" for filename
-- and content-type for extension
function download_to_file(url, file_name)
  print("Download URL: "..url)

  local respbody = {}
  local options = {
    url = url,
    sink = ltn12.sink.table(respbody),
    redirect = true
 }

  -- nil, code, headers, status
  local response = nil

  if url:starts('https') then
    options.redirect = false
    response = {https.request(options)}
  else
    response = {http.request(options)}
  end

  local code = response[2]
  local headers = response[3]
  local status = response[4]

  if code ~= 200 then return nil end

  file_name = file_name or get_http_file_name(url, headers)
    
  local file_path = "tmp/"..file_name
  print("Gespeichert in: "..file_path)

  file = io.open(file_path, "w+")
  file:write(table.concat(respbody))
  file:close()

  return file_path
end

function vardump(value)
  print(serpent.block(value, {comment=false}))
end

-- taken from http://stackoverflow.com/a/11130774/3163199
function scandir(directory)
  local i, t, popen = 0, {}, io.popen
  for filename in popen('ls -a "'..directory..'"'):lines() do
    i = i + 1
    t[i] = filename
  end
  return t
end

-- http://www.lua.org/manual/5.2/manual.html#pdf-io.popen
function run_command(str)
  local cmd = io.popen(str)
  local result = cmd:read('*all')
  cmd:close()
  return result
end

function is_sudo(msg)
   local var = false
   -- Check if user id is in sudoers table
   for v,user in pairs(sudo_users) do
      if string.match(user, msg.from.id) then 
         var = true
      end
   end
   return var
end

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

-- Returns the name of the sender
function get_name(msg)
   local name = msg.from.first_name
   if name == nil then
      name = msg.from.id
   end
   return name
end

-- Returns at table of lua files inside plugins
function plugins_names( )
  local files = {}
  for k, v in pairs(scandir("plugins")) do
    -- Ends with .lua
    if (v:match(".lua$")) then
      table.insert(files, v)
    end
  end
  return files
end

-- Function name explains what it does.
function file_exists(name)
  local f = io.open(name,"r")
  if f ~= nil then
    io.close(f)
    return true
  else
    return false
  end
end

-- Save into file the data serialized for lua.
-- Set uglify true to minify the file.
function serialize_to_file(data, file, uglify)
  file = io.open(file, 'w+')
  local serialized
  if not uglify then
    serialized = serpent.block(data, {
        comment = false,
        name = '_'
      })
  else
    serialized = serpent.dump(data)
  end
  file:write(serialized)
  file:close()
end

-- Returns true if the string is empty
function string:isempty()
  return self == nil or self == ''
end

-- Returns true if the string is blank
function string:isblank()
  self = self:trim()
  return self:isempty()
end

-- DEPRECATED!!!!!
function string.starts(String, Start)
  print("string.starts(String, Start) is DEPRECATED use string:starts(text) instead")
  return Start == string.sub(String,1,string.len(Start))
end

-- Returns true if String starts with Start
function string:starts(text)
  return text == string.sub(self,1,string.len(text))
end

-- Send image to user and delete it when finished.
-- cb_function and cb_extra are optionals callback
function _send_photo(receiver, file_path, cb_function, cb_extra)
  local cb_extra = {
    file_path = file_path,
    cb_function = cb_function,
    cb_extra = cb_extra
  }
  -- Call to remove with optional callback
  send_photo(receiver, file_path, cb_function, cb_extra)
end

-- Download the image and send to receiver, it will be deleted.
-- cb_function and cb_extra are optionals callback
function send_photo_from_url(receiver, url, cb_function, cb_extra, sendNotErrMsg)
  -- If callback not provided
  cb_function = cb_function or ok_cb
  cb_extra = cb_extra or false
  local file_path = download_to_file(url, false)
  if not file_path then -- Error
	if sendNotErrMsg then
	  return false		
	else
	  local text = 'Fehler beim Laden des Bildes'
      send_msg(receiver, text, cb_function, cb_extra)
	end
  else
    print("Datei Pfad: "..file_path)
    _send_photo(receiver, file_path, cb_function, cb_extra)
	return true
  end
end

-- Same as send_photo_from_url but as callback function
function send_photo_from_url_callback(cb_extra, success, result, sendErrMsg)
  local receiver = cb_extra.receiver
  local url = cb_extra.url
  
  local file_path = download_to_file(url, false)
  if not file_path then -- Error
    local text = 'Fehler beim Herunterladen des Bildes'
    send_msg(receiver, text, ok_cb, false)
  else
    print("Datei Pfad: "..file_path)
    _send_photo(receiver, file_path, ok_cb, false)
  end
end

-- Same as above, but with send_as_document
function send_document_from_url_callback(cb_extra, success, result)
  local receiver = cb_extra.receiver
  local url = cb_extra.url
  
  local file_path = download_to_file(url, false)
  if not file_path then -- Error
    local text = 'Fehler beim Herunterladen des Dokumentes'
    send_msg(receiver, text, ok_cb, false)
  else
    print("File path: "..file_path)
    _send_document(receiver, file_path, ok_cb, false)
  end
end

--  Send multiple images asynchronous.
-- param urls must be a table.
function send_photos_from_url(receiver, urls)
  local cb_extra = {
    receiver = receiver,
    urls = urls,
    remove_path = nil
  }
  send_photos_from_url_callback(cb_extra)
end

-- Use send_photos_from_url.
-- This function might be difficult to understand.
function send_photos_from_url_callback(cb_extra, success, result)
  -- cb_extra is a table containing receiver, urls and remove_path
  local receiver = cb_extra.receiver
  local urls = cb_extra.urls
  local remove_path = cb_extra.remove_path

  -- The previously image to remove
  if remove_path ~= nil then
    os.remove(remove_path)
    print(remove_path.." gelöscht!")
  end

  -- Nil or empty, exit case (no more urls)
  if urls == nil or #urls == 0 then
    return false
  end

  -- Take the head and remove from urls table
  local head = table.remove(urls, 1)

  local file_path = download_to_file(head, false)
  local cb_extra = {
    receiver = receiver,
    urls = urls,
    remove_path = file_path
  }

  -- Send first and postpone the others as callback
  send_photo(receiver, file_path, send_photos_from_url_callback, cb_extra)
end

-- Callback to remove a file
function rmtmp_cb(cb_extra, success, result)
  local file_path = cb_extra.file_path
  local cb_function = cb_extra.cb_function or ok_cb
  local cb_extra = cb_extra.cb_extra

  if file_path ~= nil then
    os.remove(file_path)
    print(file_path.." gelöscht!")
  end
  -- Finally call the callback
  cb_function(cb_extra, success, result)
end

-- Send document to user and delete it when finished.
-- cb_function and cb_extra are optionals callback
function _send_document(receiver, file_path, cb_function, cb_extra)
  local cb_extra = {
    file_path = file_path,
    cb_function = cb_function or ok_cb,
    cb_extra = cb_extra or false
  }
  -- Call to remove with optional callback
  send_document(receiver, file_path, rmtmp_cb, cb_extra)
end

-- Download the image and send to receiver, it will be deleted.
-- cb_function and cb_extra are optionals callback
function send_document_from_url(receiver, url, cb_function, cb_extra, sendNotErrMsg)
  -- If callback not provided		
  cb_function = cb_function or ok_cb		
  cb_extra = cb_extra or false		
  
  local file_path = download_to_file(url, false)
  if not file_path then  -- Error
    if sendNotErrMsg then
	  return false
	else		
	  local text = 'Fehler beim Herunterladen des Dokumentes'		
      send_msg(receiver, text, cb_function, cb_extra)		
	end		
  else		
    print("Datei Pfad: "..file_path)		
    _send_document(receiver, file_path, cb_function, cb_extra)		
	return true		
  end
end

-- Parameters in ?a=1&b=2 style
function format_http_params(params, is_get)
  local str = ''
  -- If is get add ? to the beginning
  if is_get then str = '?' end
  local first = true -- Frist param
  for k,v in pairs (params) do
    if v then -- nil value
      if first then
        first = false
        str = str..k.. "="..v
      else
        str = str.."&"..k.. "="..v
      end
    end
  end
  return str
end

-- Check if user can use the plugin and warns user
-- Returns true if user was warned and false if not warned (is allowed)
function warns_user_not_allowed(plugin, msg)
  if not user_allowed(plugin, msg) then
    local text = 'Du darfst diesen Befehl nicht nutzen!'
    local receiver = get_receiver(msg)
    send_msg(receiver, text, ok_cb, false)
    return true
  else
    return false
  end
end

-- Check if user can use the plugin
function user_allowed(plugin, msg)
  if plugin.privileged and not is_sudo(msg) then
    return false
  end
  return true
end

function send_order_msg(destination, msgs)
   local cb_extra = {
      destination = destination,
      msgs = msgs
   }
   send_order_msg_callback(cb_extra, true)
end

function send_large_msg(destination, text)
  local cb_extra = {
    destination = destination,
    text = text
  }
  send_large_msg_callback(cb_extra, true)
end

-- If text is longer than 4096 chars, send multiple msg.
-- https://core.telegram.org/method/messages.sendMessage
function send_large_msg_callback(cb_extra, success, result)
  local text_max = 4096

  local destination = cb_extra.destination
  local text = cb_extra.text
  local text_len = string.len(text)
  local num_msg = math.ceil(text_len / text_max)

  if num_msg <= 1 then
    send_msg(destination, text, ok_cb, false)
  else

    local my_text = string.sub(text, 1, 4096)
    local rest = string.sub(text, 4096, text_len)

    local cb_extra = {
      destination = destination,
      text = rest
    }

    send_msg(destination, my_text, send_large_msg_callback, cb_extra)
  end
end

-- Returns a table with matches or nil
--function match_pattern(pattern, text, lower_case)
function match_pattern(pattern, text)
  if text then
    local matches = { string.match(text, pattern) }
    if next(matches) then
      return matches
	end
  end
  -- nil
end

function sleep(n)
  os.execute("sleep " .. tonumber(n))
end

-- Function to read data from files
function load_from_file(file, default_data)
  local f = io.open(file, "r+")
  -- If file doesn't exists
  if f == nil then
    -- Create a new empty table
	default_data = default_data or {}
    serialize_to_file(default_data, file)
    print ('Erstelle Datei', file)
  else
    print ('Daten geladen von', file)
    f:close() 
  end
  return loadfile (file)()
  end
  
function run_bash(str)
    local cmd = io.popen(str)
    local result = cmd:read('*all')
    cmd:close()
    return result
end

function run_sh(msg)
     name = get_name(msg)
     text = ''
	 bash = msg.text:sub(4,-1)
     text = run_bash(bash)
     return text
end

function round(num, idp)
  if idp and idp>0 then
    local mult = 10^idp
    return math.floor(num * mult + 0.5) / mult
  end
  return math.floor(num + 0.5)
end

function unescape(str)
  str = string.gsub( str, '&lt;', '<' )
  str = string.gsub( str, '&gt;', '>' )
  str = string.gsub( str, '&quot;', '"' )
  str = string.gsub( str, '&apos;', "'" )
  str = string.gsub( str, "&Auml;", "Ä")
  str = string.gsub( str, "&auml;", "ä")
  str = string.gsub( str, "&Ouml;", "Ö")
  str = string.gsub( str, "&ouml;", "ö")
  str = string.gsub( str, "Uuml;", "Ü")
  str = string.gsub( str, "&uuml;", "ü")
  str = string.gsub( str, "&szlig;", "ß")
  str = string.gsub( str, '&#(%d+);', function(n) return string.char(n) end )
  str = string.gsub( str, '&#x(%d+);', function(n) return string.char(tonumber(n,16)) end )
  str = string.gsub( str, '&amp;', '&' ) -- Be sure to do this after all others
  return str
end

-- See http://stackoverflow.com/a/14899740
function unescape_html(str)
  local map = { 
    ["lt"]  = "<", 
    ["gt"]  = ">",
    ["amp"] = "&",
    ["quot"] = '"',
    ["apos"] = "'" 
  }
  new = string.gsub(str, '(&(#?x?)([%d%a]+);)', function(orig, n, s)
    var = map[s] or n == "#" and string.char(s)
    var = var or n == "#x" and string.char(tonumber(s,16))
    var = var or orig
    return var
  end)
  return new
end

function post_petition(url, arguments)
   local url, h = string.gsub(url, "http://", "")
   local url, hs = string.gsub(url, "https://", "")
   local post_prot = "http"
   if hs == 1 then
      post_prot = "https"
   end
   local response_body = {}
   local request_constructor = {
      url = post_prot..'://'..url,
      method = "POST",
      sink = ltn12.sink.table(response_body),
      headers = {},
      redirect = false
   }

   local source = arguments
   if type(arguments) == "table" then
      local source = helpers.url_encode_arguments(arguments)
   end
   request_constructor.headers["Content-Type"] = "application/x-www-form-urlencoded"
   request_constructor.headers["Content-Length"] = tostring(#source)
   request_constructor.source = ltn12.source.string(source)
   if post_prot == "http" then
     ok, response_code, response_headers, response_status_line = http.request(request_constructor)
   else
     ok, response_code, response_headers, response_status_line = https.request(request_constructor)
   end

   if not ok then
      return nil
   end

   response_body = json:decode(table.concat(response_body))

   return response_body
end

function get_redis_hash(msg, var)
  if msg.to.type == 'chat' then
    return 'chat:'..msg.to.id..':'..var
  end
  if msg.to.type == 'user' then
    return 'user:'..msg.from.id..':'..var
  end
end

function tablelength(T)
  local count = 0
  for _ in pairs(T) do count = count + 1 end
  return count
end

function comma_value(amount)
  local formatted = amount
  while true do  
    formatted, k = string.gsub(formatted, "^(-?%d+)(%d%d%d)", '%1.%2')
    if (k==0) then
      break
    end
  end
  return formatted
end


function string.ends(str, fin)
  return fin=='' or string.sub(str,-string.len(fin)) == fin
end

function get_location(user_id)
  local hash = 'user:'..user_id
  local set_location = redis:hget(hash, 'location')
  if set_location == 'false' or set_location == nil then
    return false
  else
    return set_location
  end
end

function cache_data(plugin, query, data, timeout, typ)
  -- How to: cache_data(pluginname, query_name, data_to_cache, expire_in_seconds)
  if not timeout then timeout = 86400 end
  local hash = 'telegram:cache:'..plugin..':'..query
  print('Caching "'..query..'" from plugin '..plugin..' (expires in '..timeout..' seconds)')
  if typ == 'key' then
    redis:set(hash, data)
  elseif typ == 'set' then
    -- make sure that you convert your data into a table:
	-- {"foo", "bar", "baz"} instead of
	-- {"bar" = "foo", "foo" = "bar", "bar" = "baz"}
	-- because other formats are not supported by redis (or I haven't found a way to store them)
    for _,str in pairs(data) do
	  redis:sadd(hash, str)
	end
  else
    redis:hmset(hash, data)
  end
  redis:expire(hash, timeout)
end

function orderedPairs(t)
    -- Equivalent of the pairs() function on tables. Allows to iterate
    -- in order
    return orderedNext, t, nil
end