//-----------------------------------------------------------------------
// <copyright file="GvrKeyboardIntent.cs" company="Google Inc.">
// Copyright 2017 Google Inc. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// </copyright>
//-----------------------------------------------------------------------

using System;
using UnityEngine;

/// <summary>A class for launching and managing GVR keyboard intents.</summary>
public class GvrKeyboardIntent
{
    // Constants used via JNI to access the keyboard fragment.
    private const string FRAGMENT_CLASSNAME =
        "com.google.gvr.keyboardsupport.KeyboardFragment";

    private const string CALLBACK_CLASSNAME = FRAGMENT_CLASSNAME + "$KeyboardCallback";

    // Singleton instance.
    private static GvrKeyboardIntent theInstance;

#if UNITY_ANDROID && !UNITY_EDITOR
    // The Play Store intent is requested via an Android Activity Fragment Java object.
    private AndroidJavaObject keyboardFragment = null;
#endif  // UNITY_ANDROID && !UNITY_EDITOR

    /// <summary>
    /// Gets the singleton instance of the `PermissionsRequester` class, lazily instantiated.
    /// </summary>
    /// <value>A singleton instance the `PermissionsRequester` class.</value>
    public static GvrKeyboardIntent Instance
    {
        get
        {
            if (theInstance == null)
            {
                theInstance = new GvrKeyboardIntent();
                if (!theInstance.InitializeFragment())
                {
                    Debug.LogError("Cannot initialize fragment!");
                    theInstance = null;
                }
            }

            return theInstance;
        }
    }

    /// <summary>Start the intent to launch the Play Store.</summary>
    public void LaunchPlayStore()
    {
#if !UNITY_ANDROID || UNITY_EDITOR
        Debug.LogError("GvrKeyboardIntent requires the Android runtime environment");
#else
        KeyboardCallback cb = new KeyboardCallback();
        keyboardFragment.Call("launchPlayStore", cb);
#endif  // !UNITY_ANDROID || UNITY_EDITOR
    }

    /// <summary>Initializes the fragment via JNI.</summary>
    /// <returns>True if fragment was initialized.</returns>
    protected bool InitializeFragment()
    {
#if !UNITY_ANDROID || UNITY_EDITOR
        Debug.LogWarning("GvrKeyboardIntent requires the Android runtime environment");
        return false;
#else
        AndroidJavaClass ajc = new AndroidJavaClass(FRAGMENT_CLASSNAME);

        if (ajc != null)
        {
            // Get the KeyboardFragment object
            keyboardFragment = ajc.CallStatic<AndroidJavaObject>("getInstance",
                GvrActivityHelper.GetActivity());
        }

        return keyboardFragment != null &&
        keyboardFragment.GetRawObject() != IntPtr.Zero;
#endif  // !UNITY_ANDROID || UNITY_EDITOR
    }

    /// <summary>Keyboard callback implementation.</summary>
    /// <remarks>
    /// Instances of this class are passed to the java fragment and then invoked once the request
    /// process is completed by the user.
    /// </remarks>
    internal class KeyboardCallback : AndroidJavaProxy
    {
        internal KeyboardCallback() : base(CALLBACK_CLASSNAME)
        {
        }

        /// <summary>Called when then flow is completed.</summary>
        private void onPlayStoreResult()
        {
            Application.Quit();
        }
    }
}