/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.fenix.ext

import mozilla.components.service.nimbus.NimbusApi
import mozilla.components.support.base.log.logger.Logger
import org.mozilla.fenix.FeatureFlags

/**
 * Gets the branch of the given `experimentId` and transforms it with given closure.
 *
 * If we're enrolled in the experiment, the transform is passed the branch id/slug as a `String`.
 *
 * If we're not enrolled in the experiment, or the experiment is not valid then the transform
 * is passed a `null`.
 */
@Suppress("TooGenericExceptionCaught")
fun <T> NimbusApi.withExperiment(experimentId: String, transform: (String?) -> T): T {
    val branch = if (FeatureFlags.nimbusExperiments) {
        try {
            getExperimentBranch(experimentId)
        } catch (e: Throwable) {
            Logger.error("Failed to getExperimentBranch($experimentId)", e)
            null
        }
    } else {
        null
    }
    return transform(branch)
}

/**
 * The degenerate case of `withExperiment(String, (String?) -> T))`, with an identity transform.
 *
 * Short-hand for `mozilla.components.service.nimbus.NimbusApi.getExperimentBranch`.
 */
fun NimbusApi.withExperiment(experimentId: String) =
    this.withExperiment(experimentId, ::identity)

private fun <T> identity(value: T) = value