/**
     * Part of the AuthenticationHandler interface
     *
     * Called when the Amazon Cognito service returns a valid set of tokens, when the tokens
     * are available (cached) or after successful completion of the authentication process.
     *
     * @param userSession  Contains the valid user tokens
     * @param newDevice    If this is a new device, then contains the device information
     */
    override fun onSuccess(userSession: CognitoUserSession?, newDevice: CognitoDevice?) {
        Log.i(TAG, "onSuccess()")
        val cognitoUser = (identityManager as AWSIdentityManager).userPool.currentUser
        val user = User(cognitoUser.userId)

        // This is the important token storage part
        userSession?.let {
            user.username = it.username
            user.tokens[TokenType.ACCESS_TOKEN] = userSession.accessToken.jwtToken
            user.tokens[TokenType.ID_TOKEN] = userSession.idToken.jwtToken
            user.tokens[TokenType.REFRESH_TOKEN] = userSession.refreshToken.token
        }

        // Obtain the details about the user from Amazon Cognito
        cognitoUser.getDetails(object : GetDetailsHandler {
            /**
             * This method is called on successfully fetching user attributes.
             * `attributesList` contains all attributes set for the user.
             *
             * @param cognitoUserDetails contains the users' details retrieved from the Cognito Service
             */
            override fun onSuccess(cognitoUserDetails: CognitoUserDetails?) {
                Log.i(TAG, "getDetails::onSuccess()")
                cognitoUserDetails?.let {
                    for ((key, value) in it.attributes.attributes) {
                        user.userAttributes[key] = value
                    }
                }

                Log.d(TAG, "getDetails::onSuccess(): Details received")

                runOnUiThread {
                    identityManager.signin(user)
                    this@AuthenticatorActivity.finish()
                }
            }

            /**
             * This method is called upon encountering errors during this operation.
             * Probe `exception` for the cause of this exception.
             *
             * @param exception REQUIRED: Failure details.
             */
            override fun onFailure(exception: Exception?) {
                // Print out the message - this should technically not happen
                val message: String = exception?.localizedMessage ?: "Unknown error"
                Log.e(TAG, "getDetails::onFailure $message", exception)

                runOnUiThread {
                    identityManager.signin(user)
                    this@AuthenticatorActivity.finish()
                }
            }
        })
    }

    /**
     * This method is called when a fatal exception was encountered during
     * authentication. The current authentication process continue because of the error
     * , hence a continuation is not available. Probe `exception` for details.
     *
     * @param exception is this Exception leading to authentication failure.
     */
    override fun onFailure(exception: Exception?) {
        val message: String = exception?.localizedMessage ?: "Error submitting credentials"
        Log.e(TAG, "onFailure: $message", exception)
        runOnUiThread {
            alert("Error submitting credentials") {
                title = "Login Denied"
                positiveButton("Close") { }
            }.show()
        }
    }

    /**
     * Obtain the credentials for the user.
     *
     * @param continuation A continuation object for continuing with the task
     * @param userId       The user-ID (username  or alias) used in authentication.
     */
    override fun getAuthenticationDetails(continuation: AuthenticationContinuation?, userId: String?) {
        // This should never occur!!! That's because we use initiateUserAuthentication() which gets
        // supplied with the authenticationDetails.
        Log.i(TAG, "getAuthenticationDetails()")
        val username = loginform_username.getContent()
        val password = loginform_password.getContent()
        val authDetails = AuthenticationDetails(username, password, HashMap<String, String>())
        continuation?.let {
            it.setAuthenticationDetails(authDetails)
            it.continueTask()
        }
    }

    /**
     * Call out to the dev to respond to a challenge.
     * The authentication process as presented the user with the a challenge, to successfully authenticate.
     * This a generic challenge, that is not MFA or user password verification.
     *
     * @param continuation contains details about the challenge and allows dev to respond to the
     * challenge.
     */
    @SuppressLint("InflateParams")
    override fun authenticationChallenge(continuation: ChallengeContinuation?) {
        Log.i(TAG, "authenticationChallenge: ${continuation?.challengeName}")

        when (continuation?.challengeName) {
            "NEW_PASSWORD_REQUIRED" -> {
                runOnUiThread {
                    val newPasswordDialog = layoutInflater.inflate(R.layout.dialog_new_password, null)
                    val passwordInput = newPasswordDialog.find(R.id.newpassworddialog_password) as EditText
                    alert {
                        title = "Enter New Password"
                        customView = newPasswordDialog
                        positiveButton("OK") {
                            // Respond to the challenge
                            Log.i(TAG, "authenticationChallenge: new password = ${passwordInput.getContent()}")
                            continuation.setChallengeResponse("NEW_PASSWORD", passwordInput.getContent())
                            continuation.setChallengeResponse("USERNAME", loginform_username.getContent())
                            thread(start = true) { continuation.continueTask() }
                        }
                    }.show()
                }
            }

            else -> {
                Log.e(TAG, "authenticationChallenge: error - unexpected challenge")
                throw NotImplementedError("authenticationChallenge is not implemented")
            }
        }
    }

    /**
     * Call out to the dev to send MFA code.
     * MFA code would have been sent via the deliveryMethod before this is invoked.
     * This callback can be invoked in two scenarios -
     * 1)  MFA verification is required and only one possible MFA delivery medium is
     * available.
     * 2)  MFA verification is required and a MFA delivery medium was successfully set.
     * 3)  An MFA code sent earlier was incorrect and at-least one more attempt to send
     * MFA code is available.
     *
     * @param continuation medium through which the MFA will be delivered
     */
    @Suppress("InflateParams")
    override fun getMFACode(continuation: MultiFactorAuthenticationContinuation?) {
        runOnUiThread {
            val mfaPromptDialog = layoutInflater.inflate(R.layout.dialog_mfa_prompt, null)
            val mfaInput = mfaPromptDialog.find(R.id.mfapromptdialog_code) as MFAEditText
            continuation?.let {
                val mfaInstructions = mfaPromptDialog.find(R.id.mfapromptdialog_instructions) as TextView
                mfaInstructions.text = "Enter the code we just sent to ${it.parameters.deliveryMedium}:${it.parameters.destination}"
            }
            alert {
                title = "Multi-factor Code Required"
                customView = mfaPromptDialog
                positiveButton("OK") {
                    continuation?.let {
                        Log.i(TAG, "getMFACode: new code = ${mfaInput.getContent()}")
                        it.setMfaCode(mfaInput.getContent())
                        thread(start = true) { it.continueTask() }
                    }
                }
            }.show()
        }
    }