/* 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

import android.app.Activity
import android.content.Intent
import android.os.Bundle
import androidx.annotation.VisibleForTesting
import kotlinx.coroutines.MainScope
import kotlinx.coroutines.launch
import mozilla.components.feature.intent.processing.IntentProcessor
import mozilla.components.support.utils.Browsers
import org.mozilla.fenix.components.IntentProcessors
import org.mozilla.fenix.components.metrics.Event
import org.mozilla.fenix.customtabs.ExternalAppBrowserActivity
import org.mozilla.fenix.ext.components
import org.mozilla.fenix.ext.settings
import org.mozilla.fenix.shortcut.NewTabShortcutIntentProcessor

enum class IntentProcessorType {
    EXTERNAL_APP, NEW_TAB, OTHER;

    /**
     * The destination activity based on this intent
     */
    val activityClassName: String
        get() = when (this) {
            EXTERNAL_APP -> ExternalAppBrowserActivity::class.java.name
            NEW_TAB -> HomeActivity::class.java.name
            OTHER -> HomeActivity::class.java.name
        }

    /**
     * Should this intent automatically navigate to the browser?
     */
    fun shouldOpenToBrowser(intent: Intent): Boolean = when (this) {
        EXTERNAL_APP -> true
        NEW_TAB -> intent.flags and Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY == 0
        OTHER -> false
    }
}

/**
 * Classifies the [IntentType] based on the [IntentProcessor] that handled the [Intent]
 */
fun IntentProcessor?.getType(intentProcessors: IntentProcessors): IntentProcessorType {
    return when {
        intentProcessors.externalAppIntentProcessors.contains(this) ||
            intentProcessors.customTabIntentProcessor == this ||
            intentProcessors.privateCustomTabIntentProcessor == this -> IntentProcessorType.EXTERNAL_APP
        intentProcessors.intentProcessor == this ||
                intentProcessors.privateIntentProcessor == this -> IntentProcessorType.NEW_TAB
        else -> IntentProcessorType.OTHER
    }
}

/**
 * Processes incoming intents and sends them to the corresponding activity.
 */
class IntentReceiverActivity : Activity() {

    @VisibleForTesting
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        MainScope().launch {
            // The intent property is nullable, but the rest of the code below
            // assumes it is not. If it's null, then we make a new one and open
            // the HomeActivity.
            val intent = intent?.let { Intent(intent) } ?: Intent()
            processIntent(intent)
        }
    }

    suspend fun processIntent(intent: Intent) {
        if (!Browsers.all(this).isDefaultBrowser) {
            /* If the user has unset us as the default browser, unset openLinksInAPrivateTab */
            this.settings().openLinksInAPrivateTab = false
            components.analytics.metrics.track(Event.PreferenceToggled(
                preferenceKey = getString(R.string.pref_key_open_links_in_a_private_tab),
                enabled = false,
                context = applicationContext
            ))
        }

        val modeDependentProcessors = if (settings().openLinksInAPrivateTab) {
                components.analytics.metrics.track(Event.OpenedLink(Event.OpenedLink.Mode.PRIVATE))
                listOf(
                    components.intentProcessors.privateCustomTabIntentProcessor,
                    components.intentProcessors.privateIntentProcessor
                )
            } else {
                components.analytics.metrics.track(Event.OpenedLink(Event.OpenedLink.Mode.NORMAL))
                listOf(
                    components.intentProcessors.customTabIntentProcessor,
                    components.intentProcessors.intentProcessor
                )
            }

        val intentProcessors = components.intentProcessors.externalAppIntentProcessors +
                modeDependentProcessors +
                NewTabShortcutIntentProcessor()

        // Call process for side effects, short on the first that returns true
        intentProcessors.any { it.process(intent) }

        val intentProcessorType = intentProcessors
            .firstOrNull { it.matches(intent) }
            .getType(components.intentProcessors)

        intent.setClassName(applicationContext, intentProcessorType.activityClassName)
        intent.putExtra(HomeActivity.OPEN_TO_BROWSER, intentProcessorType.shouldOpenToBrowser(intent))
        startActivity(intent)

        finish()
    }
}