RegistrationRequest

package test.thavel.webauthn.dto

import com.github.kittinunf.fuel.core.ResponseDeserializable
import com.google.gson.Gson
import com.google.gson.GsonBuilder
import duo.labs.webauthn.models.AuthenticatorMakeCredentialOptions
import duo.labs.webauthn.models.PublicKeyCredentialDescriptor
import duo.labs.webauthn.models.RpEntity
import duo.labs.webauthn.models.UserEntity
import test.thavel.webauthn.utils.ByteArrayUtils

data class RegistrationRequest (
    val publicKey: PublicKey
) {
    data class PublicKey (
        val challenge: String,
        val rp: RP,
        val user: User,
        val pubKeyCredParams: List<PubKeyCredParams>,
        val authenticatorSelection: AuthenticatorSelection,
        val timeout: Int,
        val excludeCredentials: List<ExcludeCredentials>?,
        val attestation: String
    ) {
        data class RP (
            val name: String,
            val id: String
        )

        data class User (
            val name: String,
            val displayName: String,
            val id: String
        )

        data class PubKeyCredParams (
            val type: String,
            val alg: Int
        ) {
            fun toList(): List<Any> {
                return listOf(this.type, this.alg)
            }
        }

        data class AuthenticatorSelection (
            val requireResidentKey: Boolean,
            val userVerification: String
        )

        data class ExcludeCredentials (
            val type: String,
            val id: String
        )
    }

    class Deserializer: ResponseDeserializable<RegistrationRequest> {
        override fun deserialize(content: String) = Gson().fromJson(content, RegistrationRequest::class.java)
    }

    fun format(): String {
        val algs = mutableListOf<List<Any>>()
        for (alg in publicKey.pubKeyCredParams) {
            algs.add(alg.toList())
        }
        val requireUserVerification = (publicKey.authenticatorSelection.userVerification != "")

        return GsonBuilder().create().toJson(mapOf(
            "authenticatorExtensions" to "",
            "clientDataHash" to publicKey.challenge,
            "credTypesAndPubKeyAlgs" to algs,
            "excludeCredentials" to (publicKey.excludeCredentials ?: emptyList()),
            "requireResidentKey" to publicKey.authenticatorSelection.requireResidentKey,
            "requireUserPresence" to !requireUserVerification,
            "requireUserVerification" to requireUserVerification,
            "rp" to publicKey.rp,
            "user" to publicKey.user
        ))
    }

    fun toOptions(): AuthenticatorMakeCredentialOptions {
        val rp = RpEntity()
        rp.id = publicKey.rp.id
        rp.name = publicKey.rp.name

        val user = UserEntity()
        user.id = ByteArrayUtils.decodeBase64URL(publicKey.user.id)
        user.displayName = publicKey.user.displayName
        user.name = publicKey.user.name

        val requireUserVerification = (publicKey.authenticatorSelection.userVerification != "")

        val algs = mutableListOf<android.util.Pair<String, Long>>()
        for (alg in publicKey.pubKeyCredParams) {
            algs.add(android.util.Pair(alg.type, alg.alg.toLong()))
        }

        val excludes = mutableListOf<PublicKeyCredentialDescriptor>()
        for (ex in publicKey.excludeCredentials ?: emptyList()) {
            excludes.add(PublicKeyCredentialDescriptor(
                ex.type,
                ByteArrayUtils.decodeBase64URL(ex.id),
                emptyList()
            ))
        }

        val options = AuthenticatorMakeCredentialOptions()
        options.clientDataHash = ByteArrayUtils.decodeBase64URL(publicKey.challenge)
        options.rpEntity = rp
        options.userEntity = user
        options.requireResidentKey = publicKey.authenticatorSelection.requireResidentKey
        options.requireUserPresence = !requireUserVerification
        options.requireUserVerification = requireUserVerification
        options.credTypesAndPubKeyAlgs = algs
        options.excludeCredentialDescriptorList = excludes
        return options
    }
}