package com.cofedistrict.helpers.scan

import org.bouncycastle.jce.provider.BouncyCastleProvider
import org.json.JSONException
import org.json.JSONObject
import java.io.UnsupportedEncodingException
import java.security.InvalidKeyException
import java.security.NoSuchAlgorithmException
import java.security.Security
import javax.crypto.*
import javax.crypto.spec.IvParameterSpec
import javax.crypto.spec.SecretKeySpec

object AESEncryption {
    const val AES_KEY = "YNYp!hrBMG5+hYqQ"
    const val IV_KEY = "X8rt9YYtASNVbw2X"
    fun decryptCodeFromVoucherQRCodeScan(strToDecrypt: String?): String? {

        if (strToDecrypt.isNullOrEmpty()) {
            return null
        }

        Security.addProvider(BouncyCastleProvider())
        var keyBytes: ByteArray

        try {
            keyBytes = AES_KEY.toByteArray(charset("UTF8"))
            val skey = SecretKeySpec(keyBytes, "AES")
            val input = org.bouncycastle.util.encoders.Base64
                    .decode(strToDecrypt?.trim { it <= ' ' }?.toByteArray(charset("UTF8")))

            synchronized(Cipher::class.java) {
                val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
                cipher.init(Cipher.DECRYPT_MODE, skey, IvParameterSpec(IV_KEY.toByteArray()))

                val plainText = ByteArray(cipher.getOutputSize(input.size))
                var ptLength = cipher.update(input, 0, input.size, plainText, 0)
                ptLength += cipher.doFinal(plainText, ptLength)
                val decryptedString = String(plainText)
                return try {
                    if (JSONObject(decryptedString).get("type").toString() == "COUPON" || JSONObject(decryptedString).get("type").toString() == "GIFT_CARD") {
                        JSONObject(decryptedString).get("code").toString()
                    } else {
                        null
                    }
                } catch (e: JSONException) {
                    null
                }
            }
        } catch (uee: UnsupportedEncodingException) {
            uee.printStackTrace()
        } catch (ibse: IllegalBlockSizeException) {
            ibse.printStackTrace()
        } catch (bpe: BadPaddingException) {
            bpe.printStackTrace()
        } catch (ike: InvalidKeyException) {
            ike.printStackTrace()
        } catch (nspe: NoSuchPaddingException) {
            nspe.printStackTrace()
        } catch (nsae: NoSuchAlgorithmException) {
            nsae.printStackTrace()
        } catch (e: ShortBufferException) {
            e.printStackTrace()
        }

        return null
    }
}