/* 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.components.metrics

import androidx.annotation.VisibleForTesting
import mozilla.components.browser.awesomebar.facts.BrowserAwesomeBarFacts
import mozilla.components.browser.menu.facts.BrowserMenuFacts
import mozilla.components.browser.toolbar.facts.ToolbarFacts
import mozilla.components.concept.awesomebar.AwesomeBar
import mozilla.components.feature.awesomebar.provider.BookmarksStorageSuggestionProvider
import mozilla.components.feature.awesomebar.provider.ClipboardSuggestionProvider
import mozilla.components.feature.awesomebar.provider.HistoryStorageSuggestionProvider
import mozilla.components.feature.awesomebar.provider.SearchSuggestionProvider
import mozilla.components.feature.awesomebar.provider.SessionSuggestionProvider
import mozilla.components.feature.contextmenu.facts.ContextMenuFacts
import mozilla.components.feature.customtabs.CustomTabsFacts
import mozilla.components.feature.downloads.facts.DownloadsFacts
import mozilla.components.feature.findinpage.facts.FindInPageFacts
import mozilla.components.feature.media.facts.MediaFacts
import mozilla.components.feature.prompts.dialog.LoginDialogFacts
import mozilla.components.feature.pwa.ProgressiveWebAppFacts
import mozilla.components.support.base.Component
import mozilla.components.support.base.facts.Action
import mozilla.components.support.base.facts.Fact
import mozilla.components.support.base.facts.FactProcessor
import mozilla.components.support.base.facts.Facts
import mozilla.components.support.base.log.logger.Logger
import mozilla.components.support.webextensions.facts.WebExtensionFacts
import org.mozilla.fenix.BuildConfig
import org.mozilla.fenix.GleanMetrics.Addons
import org.mozilla.fenix.GleanMetrics.PerfAwesomebar
import org.mozilla.fenix.search.awesomebar.ShortcutsSuggestionProvider

interface MetricController {
    fun start(type: MetricServiceType)
    fun stop(type: MetricServiceType)
    fun track(event: Event)

    companion object {
        fun create(
            services: List<MetricsService>,
            isDataTelemetryEnabled: () -> Boolean,
            isMarketingDataTelemetryEnabled: () -> Boolean
        ): MetricController {
            return if (BuildConfig.TELEMETRY) {
                ReleaseMetricController(
                    services,
                    isDataTelemetryEnabled,
                    isMarketingDataTelemetryEnabled
                )
            } else DebugMetricController()
        }
    }
}

@VisibleForTesting
internal class DebugMetricController(
    private val logger: Logger = Logger()
) : MetricController {

    override fun start(type: MetricServiceType) {
        logger.debug("DebugMetricController: start")
    }

    override fun stop(type: MetricServiceType) {
        logger.debug("DebugMetricController: stop")
    }

    override fun track(event: Event) {
        logger.debug("DebugMetricController: track event: $event")
    }
}

@VisibleForTesting
internal class ReleaseMetricController(
    private val services: List<MetricsService>,
    private val isDataTelemetryEnabled: () -> Boolean,
    private val isMarketingDataTelemetryEnabled: () -> Boolean
) : MetricController {
    private var initialized = mutableSetOf<MetricServiceType>()

    init {
        Facts.registerProcessor(object : FactProcessor {
            override fun process(fact: Fact) {
                fact.toEvent()?.also {
                    track(it)
                }
            }
        })
    }

    override fun start(type: MetricServiceType) {
        val isEnabled = isTelemetryEnabled(type)
        val isInitialized = isInitialized(type)
        if (!isEnabled || isInitialized) {
            return
        }

        services
            .filter { it.type == type }
            .forEach { it.start() }

        initialized.add(type)
    }

    override fun stop(type: MetricServiceType) {
        val isEnabled = isTelemetryEnabled(type)
        val isInitialized = isInitialized(type)
        if (isEnabled || !isInitialized) {
            return
        }

        services
            .filter { it.type == type }
            .forEach { it.stop() }

        initialized.remove(type)
    }

    override fun track(event: Event) {
        services
            .filter { it.shouldTrack(event) }
            .forEach {
                val isEnabled = isTelemetryEnabled(it.type)
                val isInitialized = isInitialized(it.type)
                if (!isEnabled || !isInitialized) {
                    return@forEach
                }

                it.track(event)
            }
    }

    private fun isInitialized(type: MetricServiceType): Boolean = initialized.contains(type)

    private fun isTelemetryEnabled(type: MetricServiceType): Boolean = when (type) {
        MetricServiceType.Data -> isDataTelemetryEnabled()
        MetricServiceType.Marketing -> isMarketingDataTelemetryEnabled()
    }

    @Suppress("LongMethod")
    private fun Fact.toEvent(): Event? = when (Pair(component, item)) {
        Component.FEATURE_PROMPTS to LoginDialogFacts.Items.DISPLAY -> Event.LoginDialogPromptDisplayed
        Component.FEATURE_PROMPTS to LoginDialogFacts.Items.CANCEL -> Event.LoginDialogPromptCancelled
        Component.FEATURE_PROMPTS to LoginDialogFacts.Items.NEVER_SAVE -> Event.LoginDialogPromptNeverSave
        Component.FEATURE_PROMPTS to LoginDialogFacts.Items.SAVE -> Event.LoginDialogPromptSave

        Component.FEATURE_FINDINPAGE to FindInPageFacts.Items.CLOSE -> Event.FindInPageClosed
        Component.FEATURE_FINDINPAGE to FindInPageFacts.Items.INPUT -> Event.FindInPageSearchCommitted
        Component.FEATURE_CONTEXTMENU to ContextMenuFacts.Items.ITEM -> {
            metadata?.get("item")?.let { Event.ContextMenuItemTapped.create(it.toString()) }
        }

        Component.BROWSER_TOOLBAR to ToolbarFacts.Items.MENU -> {
            metadata?.get("customTab")?.let { Event.CustomTabsMenuOpened }
        }
        Component.BROWSER_MENU to BrowserMenuFacts.Items.WEB_EXTENSION_MENU_ITEM -> {
            metadata?.get("id")?.let { Event.AddonsOpenInToolbarMenu(it.toString()) }
        }
        Component.FEATURE_CUSTOMTABS to CustomTabsFacts.Items.CLOSE -> Event.CustomTabsClosed
        Component.FEATURE_CUSTOMTABS to CustomTabsFacts.Items.ACTION_BUTTON -> Event.CustomTabsActionTapped

        Component.FEATURE_DOWNLOADS to DownloadsFacts.Items.NOTIFICATION -> {
            when (action) {
                Action.CANCEL -> Event.NotificationDownloadCancel
                Action.OPEN -> Event.NotificationDownloadOpen
                Action.PAUSE -> Event.NotificationDownloadPause
                Action.RESUME -> Event.NotificationDownloadResume
                Action.TRY_AGAIN -> Event.NotificationDownloadTryAgain
                else -> null
            }
        }

        Component.FEATURE_MEDIA to MediaFacts.Items.NOTIFICATION -> {
            when (action) {
                Action.PLAY -> Event.NotificationMediaPlay
                Action.PAUSE -> Event.NotificationMediaPause
                else -> null
            }
        }
        Component.FEATURE_MEDIA to MediaFacts.Items.STATE -> {
            when (action) {
                Action.PLAY -> Event.MediaPlayState
                Action.PAUSE -> Event.MediaPauseState
                Action.STOP -> Event.MediaStopState
                else -> null
            }
        }
        Component.SUPPORT_WEBEXTENSIONS to WebExtensionFacts.Items.WEB_EXTENSIONS_INITIALIZED -> {
            metadata?.get("installed")?.let { installedAddons ->
                if (installedAddons is List<*>) {
                    Addons.installedAddons.set(installedAddons.map { it.toString() })
                    Addons.hasInstalledAddons.set(installedAddons.size > 0)
                }
            }

            metadata?.get("enabled")?.let { enabledAddons ->
                if (enabledAddons is List<*>) {
                    Addons.enabledAddons.set(enabledAddons.map { it.toString() })
                    Addons.hasEnabledAddons.set(enabledAddons.size > 0)
                }
            }

            null
        }
        Component.BROWSER_AWESOMEBAR to BrowserAwesomeBarFacts.Items.PROVIDER_DURATION -> {
            metadata?.get(BrowserAwesomeBarFacts.MetadataKeys.DURATION_PAIR)?.let { providerTiming ->
                require(providerTiming is Pair<*, *>) { "Expected providerTiming to be a Pair" }
                when (val provider = providerTiming.first as AwesomeBar.SuggestionProvider) {
                    is HistoryStorageSuggestionProvider -> PerfAwesomebar.historySuggestions
                    is BookmarksStorageSuggestionProvider -> PerfAwesomebar.bookmarkSuggestions
                    is SessionSuggestionProvider -> PerfAwesomebar.sessionSuggestions
                    is SearchSuggestionProvider -> PerfAwesomebar.searchEngineSuggestions
                    is ClipboardSuggestionProvider -> PerfAwesomebar.clipboardSuggestions
                    is ShortcutsSuggestionProvider -> PerfAwesomebar.shortcutsSuggestions
                    // NB: add PerfAwesomebar.syncedTabsSuggestions once we're using SyncedTabsSuggestionProvider
                    else -> {
                        Logger("Metrics").error("Unknown suggestion provider: $provider")
                        null
                    }
                }?.accumulateSamples(longArrayOf(providerTiming.second as Long))
            }
            null
        }
        Component.FEATURE_PWA to ProgressiveWebAppFacts.Items.HOMESCREEN_ICON_TAP -> {
            Event.ProgressiveWebAppOpenFromHomescreenTap
        }
        Component.FEATURE_PWA to ProgressiveWebAppFacts.Items.INSTALL_SHORTCUT -> {
            Event.ProgressiveWebAppInstallAsShortcut
        }
        else -> null
    }
}