// OpenTween - Client of Twitter
// Copyright (c) 2013 kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
// All rights reserved.
//
// This file is part of OpenTween.
//
// This program 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.
//
// This program 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 this program. If not, see <http://www.gnu.org/licenses/>, or write to
// the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
// Boston, MA 02110-1301, USA.

#nullable enable

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace OpenTween
{
    /// <summary>
    /// OpenTween で使用する全てのフォームの基底となるクラス
    /// </summary>
    public class OTBaseForm : Form
    {
        /// <summary>
        /// 全てのフォームで共通して使用する UI フォント
        /// </summary>
        /// <remarks>
        /// SettingLocal.xml に FontUIGlobalStr 要素を追加する事で変更できます
        /// </remarks>
        public static Font? GlobalFont { get; set; }

        /// <summary>
        /// デザイン時のスケールと現在のスケールの比
        /// </summary>
        /// <remarks>
        /// 例えば、デザイン時が 96 dpi (96.0, 96.0) で実行時が 120dpi (120.0, 120.0) の場合は 1.25, 1.25 が返ります
        /// </remarks>
        public SizeF CurrentScaleFactor { get; private set; }

        private readonly SynchronizationContext synchronizationContext;

        protected OTBaseForm()
        {
            this.CurrentScaleFactor = new SizeF(1.0f, 1.0f);
            this.synchronizationContext = SynchronizationContext.Current;

            this.Load += (o, e) =>
            {
                // デフォルトの UI フォントを変更
                if (OTBaseForm.GlobalFont != null)
                    this.Font = OTBaseForm.GlobalFont;
            };
        }

        public Task InvokeAsync(Action x)
            => this.InvokeAsync(new Func<int>(() => { x(); return 0; }));

        public Task InvokeAsync(Func<Task> x)
            => this.InvokeAsync<Task>(x).Unwrap();

        public Task<T> InvokeAsync<T>(Func<Task<T>> x)
            => this.InvokeAsync<Task<T>>(x).Unwrap();

        /// <summary>
        /// <see cref="Control.Invoke"/> メソッドのTask版みたいなやつ
        /// </summary>
        public Task<T> InvokeAsync<T>(Func<T> x)
        {
            var tcs = new TaskCompletionSource<T>();
            this.synchronizationContext.Post(_ =>
            {
                try
                {
                    var ret = x();
                    tcs.SetResult(ret);
                }
                catch (Exception ex)
                {
                    tcs.SetException(ex);
                }
            }, null);

            return tcs.Task;
        }

        /// <summary>
        /// source で指定されたフォントのスタイルを維持しつつ GlobalFont に置き換えた Font を返します
        /// </summary>
        protected Font ReplaceToGlobalFont(Font source)
        {
            if (OTBaseForm.GlobalFont == null)
                return source;

            return new Font(OTBaseForm.GlobalFont.Name, source.Size, source.Style);
        }

        protected override void ScaleControl(SizeF factor, BoundsSpecified specified)
        {
            base.ScaleControl(factor, specified);

            const float baseDpi = 96.0f;

            this.CurrentScaleFactor = new SizeF(
                this.CurrentAutoScaleDimensions.Width / baseDpi,
                this.CurrentAutoScaleDimensions.Height / baseDpi);
        }

        /// <summary>
        /// 標準の ListView のスケーリングでは不十分な処理を補います
        /// </summary>
        public static void ScaleChildControl(ListView listview, SizeF factor)
        {
            // カラム幅
            foreach (ColumnHeader col in listview.Columns)
            {
                col.Width = ScaleBy(factor.Width, col.Width);
            }
        }

        /// <summary>
        /// 標準の VScrollBar のスケーリングでは不十分な処理を補います
        /// </summary>
        public static void ScaleChildControl(VScrollBar scrollBar, SizeF factor)
            => scrollBar.Width = ScaleBy(factor.Width, scrollBar.Width);

        /// <summary>
        /// 標準の ImageList のスケーリングでは不十分な処理を補います
        /// </summary>
        public static void ScaleChildControl(ImageList imageList, SizeF factor)
            => imageList.ImageSize = ScaleBy(factor, imageList.ImageSize);

        public static Size ScaleBy(SizeF factor, Size size)
            => Size.Round(new SizeF(size.Width * factor.Width, size.Height * factor.Height));

        public static int ScaleBy(float factor, int size)
            => (int)Math.Round(size * factor);
    }
}