package com.ti.mobpo.ui.util

import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import java.io.BufferedReader
import java.io.InputStreamReader
import java.io.PrintWriter
import java.net.Socket
import java.security.SecureRandom
import javax.crypto.Cipher
import javax.crypto.spec.IvParameterSpec
import javax.crypto.spec.SecretKeySpec

class Connect {
    companion object {
        fun decodeBase64(input: String): ByteArray {
            return android.util.Base64.decode(input, android.util.Base64.DEFAULT)
        }

        fun encodeBase64(input: ByteArray): String {
            return android.util.Base64.encodeToString(input, android.util.Base64.DEFAULT)
        }

        fun decrypt(algorithm: String, cipherText: String, key: SecretKeySpec, iv: IvParameterSpec): String {
            val cipher = Cipher.getInstance(algorithm)
            cipher.init(Cipher.DECRYPT_MODE, key, iv)
            val plainText = cipher.doFinal(decodeBase64(cipherText))
            return String(plainText)
        }

        fun encrypt(algorithm: String, inputText: String, key: SecretKeySpec, iv: IvParameterSpec): String {
            val cipher = Cipher.getInstance(algorithm)
            cipher.init(Cipher.ENCRYPT_MODE, key, iv)
            val cipherText = cipher.doFinal(inputText.toByteArray())
            return encodeBase64(cipherText)
        }

        @OptIn(ExperimentalStdlibApi::class)
        suspend fun main() {
            val host = "192.168.90.151"
            val port = 8080

            val secureRandom = SecureRandom()
            val keyBytes = ByteArray(16)
            secureRandom.nextBytes(keyBytes)
            val key = SecretKeySpec(keyBytes, "AES")

            val ivBytes = ByteArray(16)
            secureRandom.nextBytes(ivBytes)
            val iv = IvParameterSpec(ivBytes)

            val algorithm = "AES/CBC/PKCS5Padding"
            val inputText = "abcdefghigklmnopqrstuvwxyz0123456789"

            withContext(Dispatchers.IO) {
                Socket(host, port).use { socket ->
                    val writer = PrintWriter(socket.getOutputStream(), true)
                    val reader = BufferedReader(InputStreamReader(socket.getInputStream()))

                    val encodedKey = encodeBase64(keyBytes)
                    println(keyBytes.toHexString())
                    writer.println(encodedKey)

                    println(reader.readLine())

                    val encodedIV = encodeBase64(ivBytes)
                    println(ivBytes.toHexString())
                    writer.println(encodedIV)

                    println(reader.readLine())

                    val cipherText = encrypt(algorithm, inputText, key, iv)
                    println(cipherText)
                    writer.println(cipherText)

                    writer.println("END_OF_COMMUNICATION")

                    println(reader.readLine())

                    println("Client: Ready for next operation")

                    writer.println("Ready for next operation")

                    println(reader.readLine())
                }
            }
        }
    }
}