using System.ComponentModel;
using SolidBrush = System.Drawing.SolidBrush;

namespace UI_WinForms.Components;

public sealed partial class NXProgressBar : UserControl
{
    private static readonly SolidBrush BACKGROUND_NOT_FILLED = new(SystemColors.Control);
    
    private readonly SolidBrush backgroundFilled;
    private readonly SolidBrush textBrush;

    public NXProgressBar()
    {
        this.InitializeComponent();
        this.backgroundFilled = new SolidBrush(this.BackColor);
        this.textBrush = new SolidBrush(this.ForeColor);
    }

    [Category("Settings"), Description("Text to show inside the progress bar.")]
    public string InformationText { get; set; } = string.Empty;

    [Category("Settings"), Description("The current percentage [0,100] of the progress bar.")]
    public int PercentInt
    {
        get => (int) (this.PercentFloat * 100);
        set => this.PercentFloat = value / 100f;
    }

    [Category("Settings"), Description("The current percentage [0,1] of the progress bar.")]
    public float PercentFloat { get; set; } = 0;

    [Category("Settings"), Description("When true, appends the percentage to the text.")]
    public bool AppendPercentageToText { get; set; } = true;
    
    protected override void OnPaintBackground(PaintEventArgs e)
    {
        // Do not paint the background.
    }
    
    // Draw the progress bar by filling the background of the label with color:
    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);

        var width = (int) MathF.Ceiling((this.Width - this.Margin.Horizontal) * this.PercentFloat);
        var height = this.Height - this.Margin.Vertical;

        // Erase the background:
        e.Graphics.FillRectangle(BACKGROUND_NOT_FILLED, this.Margin.Left, this.Margin.Top, this.Width - this.Margin.Horizontal, height);
        
        // Draw the filled background:
        e.Graphics.FillRectangle(this.backgroundFilled, this.Margin.Left, this.Margin.Top, width, height);
        
        // Calculate the text x position by using the margin:
        var textX = this.Margin.Left + this.Padding.Left;
        
        // Calculate the text y position by considering the margin:
        var textY = (int) MathF.Ceiling((this.Height - this.Font.Height) / 2f) + this.Margin.Top + this.Padding.Top;

        // Draw the text horizontally at the beginning, and vertically centered:
        e.Graphics.DrawString(this.GetTextForRendering(), this.Font, this.textBrush, textX, textY);
    }

    private string GetTextForRendering()
    {
        var text = this.InformationText;
        if (this.AppendPercentageToText)
            text += $" ({this.PercentInt}%)";

        return text;
    }
}