#include <node.h>
#include <node_buffer.h>
#include <iostream>
#include <node_object_wrap.h>
#include <nan.h>

using namespace v8;
using namespace node;
using namespace std;
#define CRC32_CR(c,b)	(crc32_tab[((int)(c) ^ (b)) & 0xff] ^ ((c) >> 8))
class BinkpCrypt : public node::ObjectWrap { 
	public:
		static void Init(v8::Handle<v8::Object> exports);
		static Persistent<Function> js_conditioner;
		BinkpCrypt();
		static unsigned long crc32_tab[256];
	protected:
		unsigned long keys[3];
		static NAN_METHOD(New);
		static NAN_METHOD(init_keys);
		static NAN_METHOD(ndecrypt_buf);
		static NAN_METHOD(nencrypt_buf);
		static v8::Persistent<FunctionTemplate> constructor_template;
	private:
		static v8::Persistent<v8::Function> constructor;
		static int decrypt_byte(BinkpCrypt *obj);
		static void decrypt_buf (char *buf, unsigned int bufsize,BinkpCrypt *obj);
		static void encrypt_buf (char *buf, unsigned int bufsize,BinkpCrypt *obj);
		static int update_keys(int c,BinkpCrypt *obj);
		static char* test;
};
unsigned long BinkpCrypt::crc32_tab[] =
{
  0x00000000,0x77073096,0xee0e612c,0x990951ba,0x076dc419,0x706af48f,0xe963a535,0x9e6495a3,
  0x0edb8832,0x79dcb8a4,0xe0d5e91e,0x97d2d988,0x09b64c2b,0x7eb17cbd,0xe7b82d07,0x90bf1d91,
  0x1db71064,0x6ab020f2,0xf3b97148,0x84be41de,0x1adad47d,0x6ddde4eb,0xf4d4b551,0x83d385c7,
  0x136c9856,0x646ba8c0,0xfd62f97a,0x8a65c9ec,0x14015c4f,0x63066cd9,0xfa0f3d63,0x8d080df5,
  0x3b6e20c8,0x4c69105e,0xd56041e4,0xa2677172,0x3c03e4d1,0x4b04d447,0xd20d85fd,0xa50ab56b,
  0x35b5a8fa,0x42b2986c,0xdbbbc9d6,0xacbcf940,0x32d86ce3,0x45df5c75,0xdcd60dcf,0xabd13d59,
  0x26d930ac,0x51de003a,0xc8d75180,0xbfd06116,0x21b4f4b5,0x56b3c423,0xcfba9599,0xb8bda50f,
  0x2802b89e,0x5f058808,0xc60cd9b2,0xb10be924,0x2f6f7c87,0x58684c11,0xc1611dab,0xb6662d3d,
  0x76dc4190,0x01db7106,0x98d220bc,0xefd5102a,0x71b18589,0x06b6b51f,0x9fbfe4a5,0xe8b8d433,
  0x7807c9a2,0x0f00f934,0x9609a88e,0xe10e9818,0x7f6a0dbb,0x086d3d2d,0x91646c97,0xe6635c01,
  0x6b6b51f4,0x1c6c6162,0x856530d8,0xf262004e,0x6c0695ed,0x1b01a57b,0x8208f4c1,0xf50fc457,
  0x65b0d9c6,0x12b7e950,0x8bbeb8ea,0xfcb9887c,0x62dd1ddf,0x15da2d49,0x8cd37cf3,0xfbd44c65,
  0x4db26158,0x3ab551ce,0xa3bc0074,0xd4bb30e2,0x4adfa541,0x3dd895d7,0xa4d1c46d,0xd3d6f4fb,
  0x4369e96a,0x346ed9fc,0xad678846,0xda60b8d0,0x44042d73,0x33031de5,0xaa0a4c5f,0xdd0d7cc9,
  0x5005713c,0x270241aa,0xbe0b1010,0xc90c2086,0x5768b525,0x206f85b3,0xb966d409,0xce61e49f,
  0x5edef90e,0x29d9c998,0xb0d09822,0xc7d7a8b4,0x59b33d17,0x2eb40d81,0xb7bd5c3b,0xc0ba6cad,
  0xedb88320,0x9abfb3b6,0x03b6e20c,0x74b1d29a,0xead54739,0x9dd277af,0x04db2615,0x73dc1683,
  0xe3630b12,0x94643b84,0x0d6d6a3e,0x7a6a5aa8,0xe40ecf0b,0x9309ff9d,0x0a00ae27,0x7d079eb1,
  0xf00f9344,0x8708a3d2,0x1e01f268,0x6906c2fe,0xf762575d,0x806567cb,0x196c3671,0x6e6b06e7,
  0xfed41b76,0x89d32be0,0x10da7a5a,0x67dd4acc,0xf9b9df6f,0x8ebeeff9,0x17b7be43,0x60b08ed5,
  0xd6d6a3e8,0xa1d1937e,0x38d8c2c4,0x4fdff252,0xd1bb67f1,0xa6bc5767,0x3fb506dd,0x48b2364b,
  0xd80d2bda,0xaf0a1b4c,0x36034af6,0x41047a60,0xdf60efc3,0xa867df55,0x316e8eef,0x4669be79,
  0xcb61b38c,0xbc66831a,0x256fd2a0,0x5268e236,0xcc0c7795,0xbb0b4703,0x220216b9,0x5505262f,
  0xc5ba3bbe,0xb2bd0b28,0x2bb45a92,0x5cb36a04,0xc2d7ffa7,0xb5d0cf31,0x2cd99e8b,0x5bdeae1d,
  0x9b64c2b0,0xec63f226,0x756aa39c,0x026d930a,0x9c0906a9,0xeb0e363f,0x72076785,0x05005713,
  0x95bf4a82,0xe2b87a14,0x7bb12bae,0x0cb61b38,0x92d28e9b,0xe5d5be0d,0x7cdcefb7,0x0bdbdf21,
  0x86d3d2d4,0xf1d4e242,0x68ddb3f8,0x1fda836e,0x81be16cd,0xf6b9265b,0x6fb077e1,0x18b74777,
  0x88085ae6,0xff0f6a70,0x66063bca,0x11010b5c,0x8f659eff,0xf862ae69,0x616bffd3,0x166ccf45,
  0xa00ae278,0xd70dd2ee,0x4e048354,0x3903b3c2,0xa7672661,0xd06016f7,0x4969474d,0x3e6e77db,
  0xaed16a4a,0xd9d65adc,0x40df0b66,0x37d83bf0,0xa9bcae53,0xdebb9ec5,0x47b2cf7f,0x30b5ffe9,
  0xbdbdf21c,0xcabac28a,0x53b39330,0x24b4a3a6,0xbad03605,0xcdd70693,0x54de5729,0x23d967bf,
  0xb3667a2e,0xc4614ab8,0x5d681b02,0x2a6f2b94,0xb40bbe37,0xc30c8ea1,0x5a05df1b,0x2d02ef8d
};

Persistent<Function> BinkpCrypt::constructor;
Persistent<FunctionTemplate> BinkpCrypt::constructor_template;


BinkpCrypt::BinkpCrypt(){
}

void BinkpCrypt::Init(Handle<Object> exports) {
	NanScope();
	Local<FunctionTemplate> tpl = NanNew<FunctionTemplate>(New);
	tpl->SetClassName(NanNew("BinkpCrypt"));
	tpl->InstanceTemplate()->SetInternalFieldCount(1);
	NODE_SET_PROTOTYPE_METHOD(tpl, "init_keys", init_keys);
	NODE_SET_PROTOTYPE_METHOD(tpl, "decrypt_buf", ndecrypt_buf);
	NODE_SET_PROTOTYPE_METHOD(tpl, "encrypt_buf", nencrypt_buf);

NanAssignPersistent(constructor, tpl->GetFunction());
  exports->Set(NanNew("BinkpCrypt"), tpl->GetFunction());
}

NAN_METHOD(BinkpCrypt::New) {
	NanScope();
	if(!args.IsConstructCall()) {
		const int argc = 1;
    	Local<Value> argv[argc] = { args[0] };
    	Local<Function> cons = NanNew<Function>(constructor);
		NanReturnValue(cons->NewInstance(argc, argv));
	}
	BinkpCrypt *bcrypt;
	bcrypt=new BinkpCrypt();
	bcrypt->Wrap(args.This());
	NanReturnValue(args.This());
}
NAN_METHOD(BinkpCrypt::init_keys) {
	NanScope();
	static NanAsciiString pass(args[0]->ToString());
	char *password=*pass;
	BinkpCrypt* obj = ObjectWrap::Unwrap<BinkpCrypt>(args.This());
	obj->keys[0] = 305419896L;
	obj->keys[1] = 591751049L;
	obj->keys[2] = 878082192L;
	while (*password)
	{
		update_keys((int)*password,obj);
		password++;
	}
	NanReturnValue(args.This());

}
int BinkpCrypt::update_keys(int c,BinkpCrypt *obj)
{
	int keyshift;
	obj->keys[0] = CRC32_CR( obj->keys[0], c );
	obj->keys[1] += obj->keys[0] & 0xff;
	obj->keys[1] = obj->keys[1] * 134775813L + 1;
	keyshift = (int) ( obj->keys[1] >> 24 );
	obj->keys[2] = CRC32_CR( obj->keys[2], keyshift );
	return c;
}
int BinkpCrypt::decrypt_byte (BinkpCrypt* obj){
	unsigned temp;
	temp = ((unsigned)obj->keys[2] & 0xffff) | 2;
	return (int)(((temp * (temp ^ 1)) >> 8) & 0xff);
}
void BinkpCrypt::decrypt_buf (char *buf, unsigned int bufsize,BinkpCrypt* obj)
{
  while (bufsize--)
    {
      update_keys(*buf++ ^= decrypt_byte(obj),obj);
    }
}
void BinkpCrypt::encrypt_buf(char *buf, unsigned int bufsize,BinkpCrypt* obj)
{
	int t;
	while( bufsize-- ) {
		t = decrypt_byte(obj);
		update_keys( *buf ,obj);
		*buf++ ^= t;
	}
}
NAN_METHOD(BinkpCrypt::nencrypt_buf) {
	NanScope();
	unsigned int len=Buffer::Length(args[0]->ToObject());
	BinkpCrypt* obj = ObjectWrap::Unwrap<BinkpCrypt>(args.This());
	char *buf=Buffer::Data(args[0]->ToObject());
	encrypt_buf (buf,len,obj);
	NanReturnValue(NanNewBufferHandle(buf,len));
}
NAN_METHOD(BinkpCrypt::ndecrypt_buf) {
	NanScope();
	unsigned int len=Buffer::Length(args[0]->ToObject());
	BinkpCrypt* obj = ObjectWrap::Unwrap<BinkpCrypt>(args.This());
	char *buf=Buffer::Data(args[0]->ToObject());
	decrypt_buf (buf,len,obj);
	NanReturnValue(NanNewBufferHandle(buf,len));
}
void InitAll(Handle<Object> exports) {
  BinkpCrypt::Init(exports);
}
NODE_MODULE(crypt, InitAll);