using DirectShow;
using Sonic;
using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using VideoPlayLib.MadVR;

namespace VideoPlayLib
{
    internal class VideoInControl : BaseObject, IDisposable
    {
        private const int OaTrue = -1;
        private const int OaFalse = 0;

        private readonly Control _ctl;
        private readonly object _flt;

        private readonly Size _szOrignal;
        private readonly float _vdoRatio;

        private readonly IVideoWindow _ivw;
        private readonly IBasicVideo2 _ibv2;

        private readonly IMadVRInfo _imvr;

        public VideoInControl(DSFilter madVr, Control ctl, bool fitWindow = true)
        {
            _ctl = ctl;
            _flt = madVr.Value;

            _imvr = (IMadVRInfo)_flt;
            _ivw = (IVideoWindow)_flt;
            _ibv2 = (IBasicVideo2)_flt;

            _ivw.put_Owner(_ctl.Handle);
            _ivw.put_MessageDrain(_ctl.Handle);
            _ivw.put_FullScreenMode(OaFalse);
            _ivw.put_WindowStyle(0x40000000 | 0x4000000);

            CheckError(_imvr.GetSize("originalVideoSize", out _szOrignal));

            //TODO: 按媒体信息AR计算宽高比
            _vdoRatio = (float)_szOrignal.Width / _szOrignal.Height;

            if (fitWindow)
            {
                _ctl.ClientSize = _szOrignal;
            }

            ctl.Resize += EventHandler;

            EventHandler(null, null);
        }

        public VideoInControl(Graph graph, Control ctl)
        {
            _ctl = ctl;
            _flt = graph.Value;

            _ivw = (IVideoWindow)_flt;
            _ibv2 = (IBasicVideo2)_flt;

            _ivw.put_Owner(_ctl.Handle);
            _ivw.put_MessageDrain(_ctl.Handle);
            _ivw.put_FullScreenMode(OaFalse);
            _ivw.put_WindowStyle(0x40000000 | 0x4000000);

            ctl.Resize += EventHandler;

            EventHandler(null, null);
        }

        private void EventHandler(object sender, EventArgs e)
        {
            var ctl = sender as Control ?? _ctl;

            _ivw.SetWindowPosition(0, 0, ctl.ClientSize.Width, ctl.ClientSize.Height);

            if(_szOrignal==Size.Empty)
                return;

            int resultWidth, resultHeight, marginV, marginH;

            //calc lettel box
            var ctlRatio = (float)ctl.ClientSize.Width / ctl.ClientSize.Height;
            if (_vdoRatio > ctlRatio)
            {
                //width based
                resultWidth = ctl.ClientSize.Width;
                marginH = 0;
                resultHeight = (int)(((float)ctl.Width / _szOrignal.Width) * _szOrignal.Height);
                marginV = (ctl.ClientSize.Height - resultHeight) / 2;
            }
            else
            {
                //height based
                resultHeight = ctl.ClientSize.Height;
                marginV = 0;
                resultWidth = (int)(((float)ctl.Height / _szOrignal.Height) * _szOrignal.Width);
                marginH = (ctl.ClientSize.Width - resultWidth) / 2;
            }

            _ibv2.SetDestinationPosition(marginH, marginV, resultWidth, resultHeight);
        }

        public void Dispose()
        {
            Marshal.ReleaseComObject(_ivw);
            Marshal.ReleaseComObject(_ibv2);
            Marshal.ReleaseComObject(_imvr);
        }
    }
}