using System.Reflection;
using Sandbox.Game;
using VRage;

namespace PluginLoader.GUI;

public class SplashScreen : Form
{
    private const float barWidth = 0.98f; // 98% of width
    private const float barHeight = 0.06f; // 6% of height
    private readonly RectangleF bar;
    private readonly PictureBox gifBox;

    private readonly bool invalid;
    private readonly Label lbl;

    private float barValue = float.NaN;

    public SplashScreen()
    {
        Image gif;
        if (Application.OpenForms.Count == 0 || !TryLoadImage(out gif))
        {
            invalid = true;
            return;
        }

        var defaultSplash = Application.OpenForms[0];
        Size = defaultSplash.Size;
        ClientSize = defaultSplash.ClientSize;
        MyVRage.Platform.Windows.HideSplashScreen();

        Name = "SplashScreenPluginLoader";
        TopMost = true;
        FormBorderStyle = FormBorderStyle.None;

        var barSize = new SizeF(Size.Width * barWidth, Size.Height * barHeight);
        var padding = (1 - barWidth) * Size.Width * 0.5f;
        var barStart = new PointF(padding, Size.Height - barSize.Height - padding);
        bar = new(barStart, barSize);

        var lblFont = new Font(FontFamily.GenericSansSerif, 12, FontStyle.Bold);
        lbl = new()
        {
            Name = "PluginLoaderInfo",
            Font = lblFont,
            BackColor = Color.Black,
            ForeColor = Color.White,
            MaximumSize = Size,
            Size = new(Size.Width, lblFont.Height),
            TextAlign = ContentAlignment.MiddleCenter,
            Location = new(0, (int)(barStart.Y - lblFont.Height - 1))
        };
        Controls.Add(lbl);

        gifBox = new()
        {
            Name = "PluginLoaderAnimation",
            Image = gif,
            Size = Size,
            AutoSize = false,
            SizeMode = PictureBoxSizeMode.StretchImage
        };
        Controls.Add(gifBox);

        gifBox.Paint += OnPictureBoxDraw;

        CenterToScreen();
        Show();
        ForceUpdate();
    }

    public object GameInfo { get; private set; }

    private bool TryLoadImage(out Image img)
    {
        try
        {
            var myAssembly = Assembly.GetExecutingAssembly();
            var myStream = myAssembly.GetManifestResourceStream("PluginLoader.splash.gif");
            img = new Bitmap(myStream);
            return true;
        }
        catch
        {
            img = null;
            return false;
        }
    }

    public void SetText(string msg)
    {
        if (invalid)
            return;

        lbl.Text = msg;
        barValue = float.NaN;
        gifBox.Invalidate();
        ForceUpdate();
    }

    public void SetBarValue(float percent = float.NaN)
    {
        if (invalid)
            return;

        barValue = percent;
        gifBox.Invalidate();
        ForceUpdate();
    }

    private void ForceUpdate()
    {
        Application.DoEvents();
    }

    private void OnPictureBoxDraw(object sender, PaintEventArgs e)
    {
        if (!float.IsNaN(barValue))
        {
            var graphics = e.Graphics;
            graphics.FillRectangle(Brushes.DarkSlateGray, bar);
            graphics.FillRectangle(Brushes.White, new RectangleF(bar.Location, new(bar.Width * barValue, bar.Height)));
        }
    }

    public void Delete()
    {
        if (invalid)
            return;

        gifBox.Paint -= OnPictureBoxDraw;
        Close();
        Dispose();
        ForceUpdate();
        MyVRage.Platform.Windows.ShowSplashScreen(MyPerGameSettings.BasicGameInfo.SplashScreenImage, new(0.7f, 0.7f));
    }
}