local Bit = require("zmplugin.lockbox.util.bit");
local String = require("string");
local Math = require("math");
local Queue = require("zmplugin.lockbox.util.queue");

local CONSTANTS = {
	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2  };
 
 local fmt = "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x" ..
			 "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"
 
 local AND = Bit.band;
 local OR  = Bit.bor;
 local NOT = Bit.bnot;
 local XOR = Bit.bxor;
 local RROT = Bit.rrotate;
 local LSHIFT = Bit.lshift;
 local RSHIFT = Bit.rshift;
 
 --SHA2 is big-endian
 local bytes2word = function(b0, b1, b2, b3)
	 local i = b0; i = LSHIFT(i, 8);
	 i = OR(i, b1); i = LSHIFT(i, 8);
	 i = OR(i, b2); i = LSHIFT(i, 8);
	 i = OR(i, b3);
	 return i;
 end
 
 local word2bytes = function(word)
	 local b0, b1, b2, b3;
	 b3 = AND(word, 0xFF); word = RSHIFT(word, 8);
	 b2 = AND(word, 0xFF); word = RSHIFT(word, 8);
	 b1 = AND(word, 0xFF); word = RSHIFT(word, 8);
	 b0 = AND(word, 0xFF);
	 return b0, b1, b2, b3;
 end
 
 local dword2bytes = function(i)
	 local b4, b5, b6, b7 = word2bytes(i);
	 local b0, b1, b2, b3 = word2bytes(Math.floor(i / 0x100000000));
	 return b0, b1, b2, b3, b4, b5, b6, b7;
 end
 
 
 
 
 local SHA2_224 = function()
 
	 local queue = Queue();
 
	 local h0 = 0xc1059ed8;
	 local h1 = 0x367cd507;
	 local h2 = 0x3070dd17;
	 local h3 = 0xf70e5939;
	 local h4 = 0xffc00b31;
	 local h5 = 0x68581511;
	 local h6 = 0x64f98fa7;
	 local h7 = 0xbefa4fa4;
 
	 local public = {};
 
	 local processBlock = function()
		 local a = h0;
		 local b = h1;
		 local c = h2;
		 local d = h3;
		 local e = h4;
		 local f = h5;
		 local g = h6;
		 local h = h7;
 
		 local w = {};
 
		 for i = 0, 15 do
			 w[i] = bytes2word(queue.pop(), queue.pop(), queue.pop(), queue.pop());
		 end
 
		 for i = 16, 63 do
			 local s0 = XOR(RROT(w[i - 15], 7), XOR(RROT(w[i - 15], 18), RSHIFT(w[i - 15], 3)));
			 local s1 = XOR(RROT(w[i - 2], 17), XOR(RROT(w[i - 2], 19), RSHIFT(w[i - 2], 10)));
			 w[i] = AND(w[i - 16] + s0 + w[i - 7] + s1, 0xFFFFFFFF);
		 end
 
		 for i = 0, 63 do
			 local s1 = XOR(RROT(e, 6), XOR(RROT(e, 11), RROT(e, 25)));
			 local ch = XOR(AND(e, f), AND(NOT(e), g));
			 local temp1 = h + s1 + ch + CONSTANTS[i + 1] + w[i];
			 local s0 = XOR(RROT(a, 2), XOR(RROT(a, 13), RROT(a, 22)));
			 local maj = XOR(AND(a, b), XOR(AND(a, c), AND(b, c)));
			 local temp2 = s0 + maj;
 
			 h = g;
			 g = f;
			 f = e;
			 e = d + temp1;
			 d = c;
			 c = b;
			 b = a;
			 a = temp1 + temp2;
		 end
 
		 h0 = AND(h0 + a, 0xFFFFFFFF);
		 h1 = AND(h1 + b, 0xFFFFFFFF);
		 h2 = AND(h2 + c, 0xFFFFFFFF);
		 h3 = AND(h3 + d, 0xFFFFFFFF);
		 h4 = AND(h4 + e, 0xFFFFFFFF);
		 h5 = AND(h5 + f, 0xFFFFFFFF);
		 h6 = AND(h6 + g, 0xFFFFFFFF);
		 h7 = AND(h7 + h, 0xFFFFFFFF);
	 end
 
	 public.init = function()
		 queue.reset();
 
		 h0 = 0xc1059ed8;
		 h1 = 0x367cd507;
		 h2 = 0x3070dd17;
		 h3 = 0xf70e5939;
		 h4 = 0xffc00b31;
		 h5 = 0x68581511;
		 h6 = 0x64f98fa7;
		 h7 = 0xbefa4fa4;
 
		 return public;
	 end
 
	 public.update = function(bytes)
		 for b in bytes do
			 queue.push(b);
			 if queue.size() >= 64 then processBlock(); end
		 end
 
		 return public;
	 end
 
	 public.finish = function()
		 local bits = queue.getHead() * 8;
 
		 queue.push(0x80);
		 while ((queue.size() + 7) % 64) < 63 do
			 queue.push(0x00);
		 end
 
		 local b0, b1, b2, b3, b4, b5, b6, b7 = dword2bytes(bits);
 
		 queue.push(b0);
		 queue.push(b1);
		 queue.push(b2);
		 queue.push(b3);
		 queue.push(b4);
		 queue.push(b5);
		 queue.push(b6);
		 queue.push(b7);
 
		 while queue.size() > 0 do
			 processBlock();
		 end
 
		 return public;
	 end
 
	 public.asBytes = function()
		 local  b0, b1, b2, b3 = word2bytes(h0);
		 local  b4, b5, b6, b7 = word2bytes(h1);
		 local  b8, b9, b10, b11 = word2bytes(h2);
		 local b12, b13, b14, b15 = word2bytes(h3);
		 local b16, b17, b18, b19 = word2bytes(h4);
		 local b20, b21, b22, b23 = word2bytes(h5);
		 local b24, b25, b26, b27 = word2bytes(h6);
 
		 return {  b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15
				 , b16, b17, b18, b19, b20, b21, b22, b23, b24, b25, b26, b27};
	 end
 
	 public.asHex = function()
		 local  b0, b1, b2, b3 = word2bytes(h0);
		 local  b4, b5, b6, b7 = word2bytes(h1);
		 local  b8, b9, b10, b11 = word2bytes(h2);
		 local b12, b13, b14, b15 = word2bytes(h3);
		 local b16, b17, b18, b19 = word2bytes(h4);
		 local b20, b21, b22, b23 = word2bytes(h5);
		 local b24, b25, b26, b27 = word2bytes(h6);
 
		 return String.format(fmt, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15
				 , b16, b17, b18, b19, b20, b21, b22, b23, b24, b25, b26, b27);
	 end
 
	 public.asString = function()
		 local  b0, b1, b2, b3 = word2bytes(h0);
		 local  b4, b5, b6, b7 = word2bytes(h1);
		 local  b8, b9, b10, b11 = word2bytes(h2);
		 local b12, b13, b14, b15 = word2bytes(h3);
		 local b16, b17, b18, b19 = word2bytes(h4);
		 local b20, b21, b22, b23 = word2bytes(h5);
		 local b24, b25, b26, b27 = word2bytes(h6);
 
		 return string.pack(string.rep('B', 28),
			 b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13,
			 b14, b15, b16, b17, b18, b19, b20, b21, b22, b23, b24, b25, b26, b27);
	 end
 
	 return public;
 
 end
 
 return SHA2_224;