package tscipher

/*
#cgo CFLAGS: -O3
#include <stdlib.h>
char* decrypt(char* inBuff,char* buff,int buffLen,char* key,int keyLen){
         for(int i=0;i<buffLen;i++){
                 inBuff[i]=buff[buffLen-i-1]^key[i%keyLen];
        }
         return inBuff;
 }
 char* encrypt(char* inBuff,char* buff,int buffLen,char* key,int keyLen){
         for(int i=0;i<buffLen;i++){
                 inBuff[buffLen-i-1]=buff[i]^key[i%keyLen];
        }
         return inBuff;
 }
*/
import "C"

import "unsafe"

type XOR struct {
	key []byte
}

func (this *XOR) Decrypt(data []byte) (decrypted []byte, err error) {
	// decrypted = data
	// err = nil
	// return
	decrypted = make([]byte, len(data))
	// for i := 0; i < len(data); i++ {
	// 	decrypted[i] = data[len(data)-i-1] ^ this.key[i%len(this.key)]
	// 	// decrypted[i] = data[i]
	// }
	key := this.key
	C.decrypt((*C.char)(unsafe.Pointer(&decrypted[0])), (*C.char)(unsafe.Pointer(&data[0])), C.int(len(data)), (*C.char)(unsafe.Pointer(&key[0])), C.int(len(key)))
	err = nil
	return
}

func (this *XOR) Encrypt(data []byte) (encryped []byte, err error) {
	// encryped = data
	// err = nil
	// return
	encryped = make([]byte, len(data))
	// for i := 0; i < len(data); i++ {
	// 	encryped[len(data)-i-1] = data[i] ^ this.key[i%len(this.key)]
	// 	// encryped[i] = data[i]
	// }
	key := this.key
	C.encrypt((*C.char)(unsafe.Pointer(&encryped[0])), (*C.char)(unsafe.Pointer(&data[0])), C.int(len(data)), (*C.char)(unsafe.Pointer(&key[0])), C.int(len(key)))
	err = nil
	return
}

func NewXOR(key []byte) (cipher Cipher) {
	return &XOR{
		key: key,
	}
}