MsalPlugin.kt

package global.raiser.app.plugins.msal

import android.app.Activity
import com.microsoft.identity.client.AuthenticationCallback
import com.microsoft.identity.client.IAuthenticationResult
import com.microsoft.identity.client.IPublicClientApplication
import com.microsoft.identity.client.PublicClientApplication
import com.microsoft.identity.client.exception.MsalException
import global.raiser.app.R
import io.flutter.embedding.engine.plugins.FlutterPlugin
import io.flutter.plugin.common.MethodCall
import io.flutter.plugin.common.MethodChannel

class MsalPlugin(private val activity: Activity) : FlutterPlugin, MethodChannel.MethodCallHandler {

    companion object {
        const val NAME = "global.raiser/msal/methods"
        const val CANCELLATION_ERROR_CODE = "-50005"
        private val SCOPES = arrayOf("User.Read", "email")
    }

    private var methodChannel: MethodChannel? = null

    private var _client: IPublicClientApplication? = null

    override fun onAttachedToEngine(binding: FlutterPlugin.FlutterPluginBinding) {
        methodChannel = MethodChannel(binding.binaryMessenger, NAME)
        methodChannel?.setMethodCallHandler(this)
    }

    override fun onDetachedFromEngine(binding: FlutterPlugin.FlutterPluginBinding) {
        methodChannel?.setMethodCallHandler(null)
        methodChannel = null
    }

    override fun onMethodCall(call: MethodCall, result: MethodChannel.Result) {
        when (call.method) {
            "login" -> login(result)
        }
    }

    private fun login(result: MethodChannel.Result) {
        getMsalClient({ client ->
            client.acquireToken(activity, SCOPES, object : AuthenticationCallback {
                override fun onSuccess(authenticationResult: IAuthenticationResult) {
                    val data: Map<*, *> = mapOf("accessToken" to authenticationResult.accessToken,
                            "authenticationScheme" to authenticationResult.authenticationScheme,
                            "idToken" to authenticationResult.account.idToken)
                    result.success(data)
                }

                override fun onCancel() {
                    result.error(CANCELLATION_ERROR_CODE, "onCancel", null)
                }

                override fun onError(exception: MsalException) {
                    result.error(exception.errorCode, exception.message, exception.exceptionName)
                }
            })
        }, { exception ->
            result.error(exception.errorCode, exception.message, exception.exceptionName)
        })
    }

    private fun getMsalClient(onCreated: (IPublicClientApplication) -> Unit, onError: (MsalException) -> Unit) {
        _client?.let {
            onCreated(it)
            return
        }
        PublicClientApplication.create(activity, R.raw.auth_config_single_account,
                object : IPublicClientApplication.ApplicationCreatedListener {
                    override fun onCreated(application: IPublicClientApplication) {
                        onCreated(application)
                    }

                    override fun onError(exception: MsalException) {
                        onError(exception)
                    }
                }
        )
    }

}