// Copyright (c) 2022 Vuplex Inc. All rights reserved.
//
// Licensed under the Vuplex Commercial Software Library License, you may
// not use this file except in compliance with the License. You may obtain
// a copy of the License at
//
//     https://vuplex.com/commercial-library-license
//
// 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.
using System;
using UnityEngine;
using UnityEngine.Serialization;
using UnityEngine.UI;
using Vuplex.WebView.Internal;

namespace Vuplex.WebView {

    /// <summary>
    /// Like the Keyboard prefab, except optimized for use in a Canvas.
    /// You can add a CanvasKeyboard to your scene either by dragging the CanvasKeyboard.prefab file
    /// into a Canvas via the editor or by programmatically calling CanvasKeyboard.Instantiate().
    /// For an example, please see 3D WebView's CanvasWorldSpaceDemo scene.
    /// </summary>
    /// <example>
    /// <code>
    /// // Create a CanvasKeyboard.
    /// var keyboard = CanvasKeyboard.Instantiate();
    /// keyboard.transform.SetParent(canvas.transform, false);
    /// var rectTransform = keyboard.transform as RectTransform;
    /// rectTransform.anchoredPosition3D = Vector3.zero;
    /// rectTransform.offsetMin = Vector2.zero;
    /// rectTransform.offsetMax = Vector2.zero;
    /// rectTransform.sizeDelta = new Vector2(650, 162);
    /// // Hook up the keyboard so that characters are routed to a CanvasWebViewPrefab in the scene.
    /// keyboard.InputReceived += (sender, eventArgs) => {
    ///     canvasWebViewPrefab.WebView.SendKey(eventArgs.Value);
    /// };
    /// </code>
    /// </example>
    public class CanvasKeyboard : BaseKeyboard {

        /// <summary>
        /// Sets the keyboard's initial resolution in pixels per Unity unit.
        /// You can change the resolution to make the keyboard's content appear larger or smaller.
        /// For more information on scaling web content, see
        /// [this support article](https://support.vuplex.com/articles/how-to-scale-web-content).
        /// </summary>
        [Label("Resolution (px / Unity unit)")]
        [Tooltip("You can change this to make web content appear larger or smaller.")]
        [FormerlySerializedAs("InitialResolution")]
        public float Resolution = 1;

        /// <summary>
        /// Gets the WebViewPrefab used for the keyboard UI, or `null` if
        /// the keyboard hasn't finished initializing yet.
        /// You can use WaitUntilInitialized() to detect when the WebViewPrefab property is ready to use.
        /// </summary>
        /// <example>
        /// <code>
        /// await keyboard.WaitUntilInitialized();
        /// keyboard.WebViewPrefab.Clicked += (sender, eventArgs) => {
        ///     Debug.Log("Keyboard was clicked");
        /// };
        /// </code>
        /// </example>
        public CanvasWebViewPrefab WebViewPrefab { get { return (CanvasWebViewPrefab)_webViewPrefab; }}

        /// <summary>
        /// Creates a new instance.
        /// </summary>
        public static CanvasKeyboard Instantiate() {

            var prefabPrototype = (GameObject) Resources.Load("CanvasKeyboard");
            var gameObject = (GameObject) Instantiate(prefabPrototype);
            return gameObject.GetComponent<CanvasKeyboard>();
        }

        void _initCanvasKeyboard() {

            var canvasWebViewPrefab = CanvasWebViewPrefab.Instantiate(_webViewOptions);
            _webViewPrefab = canvasWebViewPrefab;
            _webViewPrefab.transform.SetParent(transform, false);
            _setLayerRecursively(_webViewPrefab.gameObject, gameObject.layer);
            var rectTransform = _webViewPrefab.transform as RectTransform;
            rectTransform.anchoredPosition3D = Vector3.zero;
            rectTransform.offsetMin = Vector2.zero;
            rectTransform.offsetMax = Vector2.zero;
            _webViewPrefab.transform.localScale = Vector3.one;
            canvasWebViewPrefab.Resolution = Resolution;
            _init();
            // Disable the image, which is just used as a placeholder in the editor.
            var image = GetComponent<Image>();
            if (image != null) {
                image.enabled = false;
            }
        }

        void Start() => _initCanvasKeyboard();

        // Added in v3.12, deprecated in v4.0.
        [Obsolete("CanvasKeyboard.InitialResolution is now deprecated. Please use CanvasKeyboard.Resolution instead.")]
        public float InitialResolution {
            get { return Resolution; }
            set { Resolution = value; }
        }
    }
}