/* 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 net.waterfox.android.addons

import android.content.Context
import android.graphics.Typeface
import android.graphics.fonts.FontStyle.FONT_WEIGHT_MEDIUM
import android.os.Build
import android.os.Bundle
import android.view.View
import android.view.accessibility.AccessibilityEvent
import androidx.annotation.VisibleForTesting
import androidx.core.view.isVisible
import androidx.fragment.app.Fragment
import androidx.lifecycle.lifecycleScope
import androidx.navigation.fragment.findNavController
import androidx.recyclerview.widget.LinearLayoutManager
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Dispatchers.IO
import kotlinx.coroutines.launch
import mozilla.components.concept.engine.webextension.InstallationMethod
import mozilla.components.feature.addons.Addon
import mozilla.components.feature.addons.AddonManager
import mozilla.components.feature.addons.AddonManagerException
import mozilla.components.feature.addons.ui.AddonsManagerAdapter
import mozilla.components.feature.addons.ui.AddonsManagerAdapterDelegate
import net.waterfox.android.BrowserDirection
import net.waterfox.android.BuildConfig
import net.waterfox.android.HomeActivity
import net.waterfox.android.R
import net.waterfox.android.components.WaterfoxSnackbar
import net.waterfox.android.databinding.FragmentAddOnsManagementBinding
import net.waterfox.android.ext.components
import net.waterfox.android.ext.requireComponents
import net.waterfox.android.ext.runIfFragmentIsAttached
import net.waterfox.android.ext.settings
import net.waterfox.android.ext.showToolbar
import net.waterfox.android.settings.SupportUtils
import net.waterfox.android.theme.ThemeManager

/**
 * Fragment use for managing add-ons.
 */
@Suppress("TooManyFunctions", "LargeClass")
class AddonsManagementFragment : Fragment(R.layout.fragment_add_ons_management) {

    private var binding: FragmentAddOnsManagementBinding? = null

    private var addons: List<Addon> = emptyList()

    private var adapter: AddonsManagerAdapter? = null

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding = FragmentAddOnsManagementBinding.bind(view)
        bindRecyclerView()
        (activity as HomeActivity).webExtensionPromptFeature.onAddonChanged = {
            runIfFragmentIsAttached {
                adapter?.updateAddon(it)
            }
        }
    }

    override fun onResume() {
        super.onResume()
        showToolbar(getString(R.string.preferences_addons))
    }

    override fun onDestroyView() {
        super.onDestroyView()
        // letting go of the resources to avoid memory leak.
        adapter = null
        binding = null
        (activity as HomeActivity).webExtensionPromptFeature.onAddonChanged = {}
    }

    private fun bindRecyclerView() {
        val managementView = AddonsManagementView(
            navController = findNavController(),
            onInstallButtonClicked = ::installAddon,
            onMoreAddonsButtonClicked = ::openAMO,
            onLearnMoreClicked = ::openLearnMoreLink,
        )

        val recyclerView = binding?.addOnsList
        recyclerView?.layoutManager = LinearLayoutManager(requireContext())
        val shouldRefresh = adapter != null

        lifecycleScope.launch(IO) {
            try {
                addons = requireContext().components.addonManager.getAddons()
                // Add-ons that should be excluded in Mozilla Online builds
                val excludedAddonIDs = emptyList<String>()
                lifecycleScope.launch(Dispatchers.Main) {
                    runIfFragmentIsAttached {
                        if (!shouldRefresh) {
                            adapter = AddonsManagerAdapter(
                                addonsManagerDelegate = managementView,
                                addons = addons,
                                style = createAddonStyle(requireContext()),
                                excludedAddonIDs = excludedAddonIDs,
                                store = requireComponents.core.store,
                            )
                        }
                        binding?.addOnsProgressBar?.isVisible = false
                        binding?.addOnsEmptyMessage?.isVisible = false

                        recyclerView?.adapter = adapter
                        if (shouldRefresh) {
                            adapter?.updateAddons(addons)
                        }
                    }
                }
            } catch (e: AddonManagerException) {
                lifecycleScope.launch(Dispatchers.Main) {
                    runIfFragmentIsAttached {
                        binding?.let {
                            showSnackBar(
                                it.root,
                                getString(mozilla.components.feature.addons.R.string.mozac_feature_addons_failed_to_query_extensions),
                            )
                        }
                        binding?.addOnsProgressBar?.isVisible = false
                        binding?.addOnsEmptyMessage?.isVisible = true
                    }
                }
            }
        }
    }

    @VisibleForTesting
    internal fun showErrorSnackBar(text: String, anchorView: View? = this.view) {
        runIfFragmentIsAttached {
            anchorView?.let {
                showSnackBar(it, text, WaterfoxSnackbar.LENGTH_LONG)
            }
        }
    }

    private fun createAddonStyle(context: Context): AddonsManagerAdapter.Style {
        val sectionsTypeFace = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            Typeface.create(Typeface.DEFAULT, FONT_WEIGHT_MEDIUM, false)
        } else {
            Typeface.create(Typeface.DEFAULT, Typeface.BOLD)
        }

        return AddonsManagerAdapter.Style(
            sectionsTextColor = ThemeManager.resolveAttribute(R.attr.textPrimary, context),
            addonNameTextColor = ThemeManager.resolveAttribute(R.attr.textPrimary, context),
            addonSummaryTextColor = ThemeManager.resolveAttribute(R.attr.textSecondary, context),
            sectionsTypeFace = sectionsTypeFace,
            addonAllowPrivateBrowsingLabelDrawableRes = R.drawable.ic_add_on_private_browsing_label,
        )
    }

    @VisibleForTesting
    internal fun provideAddonManger(): AddonManager {
        return requireContext().components.addonManager
    }

    internal fun provideAccessibilityServicesEnabled(): Boolean {
        return requireContext().settings().accessibilityServicesEnabled
    }

    internal fun installAddon(addon: Addon) {
        binding?.addonProgressOverlay?.overlayCardView?.visibility = View.VISIBLE
        if (provideAccessibilityServicesEnabled()) {
            binding?.let { announceForAccessibility(it.addonProgressOverlay.addOnsOverlayText.text) }
        }
        val installOperation = provideAddonManger().installAddon(
            url = addon.downloadUrl,
            installationMethod = InstallationMethod.MANAGER,
            onSuccess = {
                runIfFragmentIsAttached {
                    adapter?.updateAddon(it)
                    binding?.addonProgressOverlay?.overlayCardView?.visibility = View.GONE
                }
            },
            onError = { _ ->
                binding?.addonProgressOverlay?.overlayCardView?.visibility = View.GONE
            },
        )
        binding?.addonProgressOverlay?.cancelButton?.setOnClickListener {
            lifecycleScope.launch(Dispatchers.Main) {
                val safeBinding = binding
                // Hide the installation progress overlay once cancellation is successful.
                if (installOperation.cancel().await()) {
                    safeBinding?.addonProgressOverlay?.overlayCardView?.visibility = View.GONE
                }
            }
        }
    }

    private fun announceForAccessibility(announcementText: CharSequence) {
        val event = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
            AccessibilityEvent(AccessibilityEvent.TYPE_ANNOUNCEMENT)
        } else {
            @Suppress("DEPRECATION")
            AccessibilityEvent.obtain(AccessibilityEvent.TYPE_ANNOUNCEMENT)
        }

        binding?.addonProgressOverlay?.overlayCardView?.onInitializeAccessibilityEvent(event)
        event.text.add(announcementText)
        event.contentDescription = null
        binding?.addonProgressOverlay?.overlayCardView?.let {
            it.parent?.requestSendAccessibilityEvent(
                it,
                event,
            )
        }
    }

    private fun openAMO() {
        openLinkInNewTab(AMO_HOMEPAGE_FOR_ANDROID)
    }

    private fun openLearnMoreLink(link: AddonsManagerAdapterDelegate.LearnMoreLinks, addon: Addon) {
        val url = when (link) {
            AddonsManagerAdapterDelegate.LearnMoreLinks.BLOCKLISTED_ADDON ->
                "${BuildConfig.AMO_BASE_URL}/android/blocked-addon/${addon.id}/"
            AddonsManagerAdapterDelegate.LearnMoreLinks.ADDON_NOT_CORRECTLY_SIGNED ->
                SupportUtils.getSumoURLForTopic(requireContext(), SupportUtils.SumoTopic.UNSIGNED_ADDONS)
        }
        openLinkInNewTab(url)
    }

    private fun openLinkInNewTab(url: String) {
        (activity as HomeActivity).openToBrowserAndLoad(
            searchTermOrURL = url,
            newTab = true,
            from = BrowserDirection.FromAddonsManagementFragment,
        )
    }

    companion object {
        // This is locale-less on purpose so that the content negotiation happens on the AMO side because the current
        // user language might not be supported by AMO and/or the language might not be exactly what AMO is expecting
        // (e.g. `en` instead of `en-US`).
        private const val AMO_HOMEPAGE_FOR_ANDROID = "${BuildConfig.AMO_BASE_URL}/android/"
    }
}