/*
 * Copyright © 2021 Soren Stoutner <soren@stoutner.com>.
 *
 * This file is part of Privacy Cell <https://www.stoutner.com/privacy-cell>.
 *
 * Privacy Cell is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Privacy Cell is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Privacy Browser.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.stoutner.privacycell.dialogs

import android.app.Dialog
import android.content.res.Configuration
import android.os.Bundle
import android.webkit.WebView

import androidx.appcompat.app.AlertDialog
import androidx.fragment.app.DialogFragment
import androidx.webkit.WebSettingsCompat
import androidx.webkit.WebViewFeature

import com.stoutner.privacycell.R

// Define the class constants.
private const val DIALOG_TYPE = "dialog_type"
private const val SCROLL_Y = "scroll_y"

class WebViewDialog : DialogFragment() {
    companion object {
        // Define the public constants.
        const val PERMISSIONS = 0
        const val PRIVACY_POLICY = 1
        const val CHANGELOG = 2
    }

    // Define the class views.
    private lateinit var webView: WebView

    // Populate the WebView dialog type.
    fun type(dialogType: Int): WebViewDialog {
        // Create an arguments bundle.
        val argumentsBundle = Bundle()

        // Add the dialog type to the bundle.
        argumentsBundle.putInt(DIALOG_TYPE, dialogType)

        // Create a new instance of the WebView dialog.
        val webViewDialog = WebViewDialog()

        // Add the arguments bundle to the new dialog.
        webViewDialog.arguments = argumentsBundle

        // Return the new dialog.
        return webViewDialog
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        // Get the dialog type from the arguments bundle.
        val dialogType = requireArguments().getInt(DIALOG_TYPE)

        // Use a builder to create the alert dialog.
        val dialogBuilder = AlertDialog.Builder(requireContext(), R.style.Theme_PrivacyCellAlertDialog)

        // Set the icon and the title according to the dialog type.
        when (dialogType) {
            PERMISSIONS -> {
                // Set the icon.
                dialogBuilder.setIcon(R.drawable.permissions)

                // Set the title.
                dialogBuilder.setTitle(R.string.permissions)
            }

            PRIVACY_POLICY -> {
                // Set the icon.
                dialogBuilder.setIcon(R.drawable.privacy_policy)

                // Set the title.
                dialogBuilder.setTitle(R.string.privacy_policy)
            }

            CHANGELOG -> {
                // Set the icon.
                dialogBuilder.setIcon(R.drawable.changelog)

                // Set the title.
                dialogBuilder.setTitle(R.string.changelog)
            }
        }

        // Set the view.
        dialogBuilder.setView(R.layout.webview_dialog)

        // Set a listener on the close button.  Using `null` as the listener closes the dialog without doing anything else.
        dialogBuilder.setNegativeButton(R.string.close, null)

        // Create an alert dialog from the builder.
        val alertDialog = dialogBuilder.create()

        // The alert dialog needs to be shown before the contents can be modified.
        alertDialog.show()

        // Get a handle for the WebView.
        webView = alertDialog.findViewById(R.id.webview)!!

        // Get the current theme status.
        val currentThemeStatus = resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK

        // Check to see if the app is in night mode.
        if (currentThemeStatus == Configuration.UI_MODE_NIGHT_YES && WebViewFeature.isFeatureSupported(WebViewFeature.FORCE_DARK)) {  // The app is in night mode.
            // Apply the dark WebView theme.
            WebSettingsCompat.setForceDark(webView.settings, WebSettingsCompat.FORCE_DARK_ON)
        }

        // Create a WebView asset loader.  TODO.
        // val webViewAssetLoader = WebViewAssetLoader.Builder().addPathHandler("/assets/", WebViewAssetLoader.AssetsPathHandler(requireContext())).build()

        // Load the WebView data according to the dialog type.
        when (dialogType) {
            PERMISSIONS -> webView.loadUrl("file:///android_asset/en/permissions.html")
            PRIVACY_POLICY -> webView.loadUrl("file:///android_asset/en/privacy_policy.html")
            CHANGELOG -> webView.loadUrl("file:///android_asset/en/changelog.html")
        }

        // Scroll the WebView if the saved instance state is not null.
        if (savedInstanceState != null) {
            webView.post {
                webView.scrollY = savedInstanceState.getInt(SCROLL_Y)
            }
        }

        // Return the alert dialog.
        return alertDialog
    }

    override fun onSaveInstanceState(savedInstanceState: Bundle) {
        // Run the default commands.
        super.onSaveInstanceState(savedInstanceState)

        // Save the scroll position.
        savedInstanceState.putInt(SCROLL_Y, webView.scrollY)
    }
}