/* 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.experiments

import android.content.Context
import mozilla.components.service.nimbus.NimbusApi
import mozilla.components.service.nimbus.NimbusAppInfo
import mozilla.components.service.nimbus.NimbusBuilder
import mozilla.components.support.base.log.logger.Logger
import org.json.JSONObject
import org.mozilla.experiments.nimbus.internal.NimbusException
import org.mozilla.fenix.BuildConfig
import org.mozilla.fenix.R
import org.mozilla.fenix.ext.components
import org.mozilla.fenix.ext.settings
import org.mozilla.fenix.nimbus.FxNimbus

/**
 * The maximum amount of time the app launch will be blocked to load experiments from disk.
 *
 * ⚠️ This value was decided from analyzing the Focus metrics (nimbus_initial_fetch) for the ideal
 * timeout. We should NOT change this value without collecting more metrics first.
 */
private const val TIME_OUT_LOADING_EXPERIMENT_FROM_DISK_MS = 200L

/**
 * Create the Nimbus singleton object for the Fenix app.
 */
fun createNimbus(context: Context, urlString: String?): NimbusApi {
    val isAppFirstRun = context.settings().isFirstNimbusRun
    if (isAppFirstRun) {
        context.settings().isFirstNimbusRun = false
    }

    // These values can be used in the JEXL expressions when targeting experiments.
    val customTargetingAttributes = JSONObject().apply {
        // By convention, we should use snake case.
        put("is_first_run", isAppFirstRun)

        // This camelCase attribute is a boolean value represented as a string.
        // This is left for backwards compatibility.
        put("isFirstRun", isAppFirstRun.toString())
    }

    // The name "fenix" here corresponds to the app_name defined for the family of apps
    // that encompasses all of the channels for the Fenix app.  This is defined upstream in
    // the telemetry system. For more context on where the app_name come from see:
    // https://probeinfo.telemetry.mozilla.org/v2/glean/app-listings
    // and
    // https://github.com/mozilla/probe-scraper/blob/master/repositories.yaml
    val appInfo = NimbusAppInfo(
        appName = "fenix",
        // Note: Using BuildConfig.BUILD_TYPE is important here so that it matches the value
        // passed into Glean. `Config.channel.toString()` turned out to be non-deterministic
        // and would mostly produce the value `Beta` and rarely would produce `beta`.
        channel = BuildConfig.BUILD_TYPE.let { if (it == "debug") "developer" else it },
        customTargetingAttributes = customTargetingAttributes,
    )

    return NimbusBuilder(context).apply {
        url = urlString
        errorReporter = { message, e ->
            Logger.error("Nimbus error: $message", e)
            if (e !is NimbusException || e.isReportableError()) {
                context.components.analytics.crashReporter.submitCaughtException(e)
            }
        }
        initialExperiments = R.raw.initial_experiments
        timeoutLoadingExperiment = TIME_OUT_LOADING_EXPERIMENT_FROM_DISK_MS
        usePreviewCollection = context.settings().nimbusUsePreview
        isFirstRun = isAppFirstRun
        onCreateCallback = { nimbus ->
            FxNimbus.initialize { nimbus }
        }
        onApplyCallback = {
            FxNimbus.invalidateCachedValues()
        }
    }.build(appInfo)
}

/**
 * Classifies which errors we should forward to our crash reporter or not. We want to filter out the
 * non-reportable ones if we know there is no reasonable action that we can perform.
 *
 * This fix should be upstreamed as part of: https://github.com/mozilla/application-services/issues/4333
 */
fun NimbusException.isReportableError(): Boolean {
    return when (this) {
        is NimbusException.RequestException,
        is NimbusException.ResponseException,
        -> false
        else -> true
    }
}