/*
 * Copyright 2017-2024 Soren Stoutner <soren@stoutner.com>.
 *
 * This file is part of Privacy Browser Android <https://www.stoutner.com/privacy-browser-android>.
 *
 * Privacy Browser Android 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 Browser Android 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 Android.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.stoutner.privacybrowser.dialogs

import android.app.Dialog
import android.content.Context
import android.content.DialogInterface
import android.os.Bundle
import android.text.Editable
import android.text.TextWatcher
import android.view.KeyEvent
import android.view.View
import android.view.WindowManager
import android.widget.EditText
import android.widget.TextView

import androidx.appcompat.app.AlertDialog
import androidx.fragment.app.DialogFragment
import androidx.preference.PreferenceManager

import com.stoutner.privacybrowser.R
import com.stoutner.privacybrowser.helpers.DomainsDatabaseHelper

class AddDomainDialog : DialogFragment() {
    // Declare the class variables
    private lateinit var addDomainListener: AddDomainListener

    // The public interface is used to send information back to the parent activity.
    interface AddDomainListener {
        fun addDomain(dialogFragment: DialogFragment)
    }

    override fun onAttach(context: Context) {
        // Run the default commands.
        super.onAttach(context)

        // Get a handle for the listener from the launching context.
        addDomainListener = context as AddDomainListener
    }

    override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
        // Use an alert dialog builder to create the alert dialog.
        val dialogBuilder = AlertDialog.Builder(requireContext(), R.style.PrivacyBrowserAlertDialog)

        // Set the icon.
        dialogBuilder.setIcon(R.drawable.domains)

        // Set the title.
        dialogBuilder.setTitle(R.string.add_domain)

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

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

        // Set the add button listener.
        dialogBuilder.setPositiveButton(R.string.add) { _: DialogInterface, _: Int ->
            // Return the dialog fragment to the parent activity on add.
            addDomainListener.addDomain(this)
        }

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

        // Get a handle for the shared preferences.
        val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(requireContext())

        // Get the screenshot preference.
        val allowScreenshots = sharedPreferences.getBoolean(getString(R.string.allow_screenshots_key), false)

        // Disable screenshots if not allowed.
        if (!allowScreenshots) {
            alertDialog.window!!.addFlags(WindowManager.LayoutParams.FLAG_SECURE)
        }

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

        // Initialize the domains database helper.
        val domainsDatabaseHelper = DomainsDatabaseHelper(requireContext())

        // Get handles for the views in the alert dialog.
        val addDomainEditText = alertDialog.findViewById<EditText>(R.id.domain_name_edittext)!!
        val domainNameAlreadyExistsTextView = alertDialog.findViewById<TextView>(R.id.domain_name_already_exists_textview)!!
        val addButton = alertDialog.getButton(AlertDialog.BUTTON_POSITIVE)

        // Initially disable the add button.
        addButton.isEnabled = false

        //  Update the status of the warning text and the add button when the domain name changes.
        addDomainEditText.addTextChangedListener(object: TextWatcher {
            override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {
                // Do nothing.
            }

            override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
                // Do nothing.
            }

            override fun afterTextChanged(editable: Editable) {
                if (domainsDatabaseHelper.getCursorForDomainName(addDomainEditText.text.toString()).count > 0) {  // The domain already exists.
                    // Show the warning text.
                    domainNameAlreadyExistsTextView.visibility = View.VISIBLE

                    // Disable the add button.
                    addButton.isEnabled = false
                } else {  // The domain do not yet exist.
                    // Hide the warning text.
                    domainNameAlreadyExistsTextView.visibility = View.GONE

                    // Enable the add button if the domain name is not empty.
                    addButton.isEnabled = editable.isNotEmpty()
                }
            }
        })

        // Allow the enter key on the keyboard to create the domain from the add domain edit text.
        addDomainEditText.setOnKeyListener { _: View, keyCode: Int, keyEvent: KeyEvent ->
            // Check the key code and event.
            if (keyCode == KeyEvent.KEYCODE_ENTER && keyEvent.action == KeyEvent.ACTION_DOWN) {  // The event is a key-down on the enter key.
                // Trigger the add domain listener and return the dialog fragment to the parent activity.
                addDomainListener.addDomain(this)

                // Manually dismiss the alert dialog.
                alertDialog.dismiss()

                // Consume the event.
                return@setOnKeyListener true
            } else {  // Some other key was pressed.
                // Do not consume the event.
                return@setOnKeyListener false
            }
        }

        // Return the alert dialog.
        return alertDialog
    }
}