--[[
Cleverbot client for ComputerCraft v1.0
Based on https://code.google.com/p/chatter-bot-api/

This code uses a pure lua implementation of the MD5 hash algortihm by Adam Baldwin as presented
in this Stack Overflow answer: http://stackoverflow.com/a/12292659

Usage:
	pastebin get Dv9x1ppc cleverbot
	cleverbot start

If a Chat Box (from Misc Peripherals) is connected to the computer the client uses it. Voice commands are activated by prepending the message with "Jarvis:" or "Jarvis," or just "Jarvis ". The name and delimiters can be customized by changing the relevant variables. Without a Chat Box the code responds to typed messages on the computer (no need to use the name, just type the message).

This same file can also be used as an API.

Example code:
		os.load("cleverbot")

		bot = cleverbot.Cleverbot.new()

		message = "Hi there!"
		response = bot:send(message) -- use of : is important here because of self reference
		print(response)

Notes:
	* Sending the message is pretty slow as the hashing takes time and cleverbot.com can sometimes take a while to respond. On slower computers this can sometimes lead to "too long without yielding" error.

Matti Vapa (2013)
]]--


-- Here are the (slightly modified) LuaBit and MD5 implementations with original comments

--[[---------------
LuaBit v0.4
-------------------
a bitwise operation lib for lua.

http://luaforge.net/projects/bit/

How to use:
-------------------
 bit.bnot(n) -- bitwise not (~n)
 bit.band(m, n) -- bitwise and (m & n)
 bit.bor(m, n) -- bitwise or (m | n)
 bit.bxor(m, n) -- bitwise xor (m ^ n)
 bit.brshift(n, bits) -- right shift (n >> bits)
 bit.blshift(n, bits) -- left shift (n << bits)
 bit.blogic_rshift(n, bits) -- logic right shift(zero fill >>>)

Please note that bit.brshift and bit.blshift only support number within
32 bits.

2 utility functions are provided too:
 bit.tobits(n) -- convert n into a bit table(which is a 1/0 sequence)
               -- high bits first
 bit.tonumb(bit_tbl) -- convert a bit table into a number
-------------------

Under the MIT license.

copyright(c) 2006~2007 hanzhao ([email protected])
--]]---------------

--do

------------------------
-- bit lib implementions

local function check_int(n)
 -- checking not float
 if(n - math.floor(n) > 0) then
  error("trying to use bitwise operation on non-integer!")
 end
end

local function tbl_to_number(tbl)
 local n = #tbl

 local rslt = 0
 local power = 1
 for i = 1, n do
  rslt = rslt + tbl[i]*power
  power = power*2
 end

 return rslt
end

local function expand(tbl_m, tbl_n)
 local big = {}
 local small = {}
 if(#tbl_m > #tbl_n) then
  big = tbl_m
  small = tbl_n
 else
  big = tbl_n
  small = tbl_m
 end
 -- expand small
 for i = #small + 1, #big do
  small[i] = 0
 end

end

local to_bits = function () end

local function bit_not(n)
 local tbl = to_bits(n)
 local size = math.max(#tbl, 32)
 for i = 1, size do
  if(tbl[i] == 1) then
   tbl[i] = 0
  else
   tbl[i] = 1
  end
 end
 return tbl_to_number(tbl)
end


to_bits = function (n)
 check_int(n)
 if(n < 0) then
  -- negative
  return to_bits(bit_not(math.abs(n)) + 1)
 end
 -- to bits table
 local tbl = {}
 local cnt = 1
 while (n > 0) do
  local last = math.fmod(n,2)
  if(last == 1) then
   tbl[cnt] = 1
  else
   tbl[cnt] = 0
  end
  n = (n-last)/2
  cnt = cnt + 1
 end

 return tbl
end


local function bit_or(m, n)
 local tbl_m = to_bits(m)
 local tbl_n = to_bits(n)
 expand(tbl_m, tbl_n)

 local tbl = {}
 local rslt = math.max(#tbl_m, #tbl_n)
 for i = 1, rslt do
  if(tbl_m[i]== 0 and tbl_n[i] == 0) then
   tbl[i] = 0
  else
   tbl[i] = 1
  end
 end

 return tbl_to_number(tbl)
end

local function bit_and(m, n)
 local tbl_m = to_bits(m)
 local tbl_n = to_bits(n)
 expand(tbl_m, tbl_n)

 local tbl = {}
 local rslt = math.max(#tbl_m, #tbl_n)
 for i = 1, rslt do
  if(tbl_m[i]== 0 or tbl_n[i] == 0) then
   tbl[i] = 0
  else
   tbl[i] = 1
  end
 end

 return tbl_to_number(tbl)
end

local function bit_xor(m, n)
 local tbl_m = to_bits(m)
 local tbl_n = to_bits(n)
 expand(tbl_m, tbl_n)

 local tbl = {}
 local rslt = math.max(#tbl_m, #tbl_n)
 for i = 1, rslt do
  if(tbl_m[i] ~= tbl_n[i]) then
   tbl[i] = 1
  else
   tbl[i] = 0
  end
 end

 --table.foreach(tbl, print)

 return tbl_to_number(tbl)
end

local function bit_rshift(n, bits)
 check_int(n)

 local high_bit = 0
 if(n < 0) then
  -- negative
  n = bit_not(math.abs(n)) + 1
  high_bit = 2147483648 -- 0x80000000
 end

 for i=1, bits do
  n = n/2
  n = bit_or(math.floor(n), high_bit)
 end
 return math.floor(n)
end

-- logic rightshift assures zero filling shift
local function bit_logic_rshift(n, bits)
 check_int(n)
 if(n < 0) then
  -- negative
  n = bit_not(math.abs(n)) + 1
 end
 for i=1, bits do
  n = n/2
 end
 return math.floor(n)
end

local function bit_lshift(n, bits)
 check_int(n)

 if(n < 0) then
  -- negative
  n = bit_not(math.abs(n)) + 1
 end

 for i=1, bits do
  n = n*2
 end
 return bit_and(n, 4294967295) -- 0xFFFFFFFF
end

local function bit_xor2(m, n)
 local rhs = bit_or(bit_not(m), bit_not(n))
 local lhs = bit_or(m, n)
 local rslt = bit_and(lhs, rhs)
 return rslt
end
local md5={ff=tonumber(ffffffff,16),consts={}}