using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using MonoGameLibrary.Graphics;

namespace ONDClient.GUI;

public class TextUIElement : UIElement {
    public SpriteFont Font { get; set; }
    public Alignment CurrentAlignment { get; set; }

    public string Text{
        get;
        set{
            field = value;
            if(AutoBounds)
                Bounds = (Bounds.Item1, Bounds.Item1 + new Point((int)Measure().X, (int)Measure().Y));
        }
    } = "";

    public Color Color{ get; set; } = Color.White;
    public bool AutoBounds{ get; protected set; } = false;
    private Vector2 origin;
    private const float UNIVERSAL_TEXT_SCALE_MULTIPLIER = 0.3f;
    
    public TextUIElement(Point corner1, SpriteFont font, Alignment alignment = Alignment.LEFT, bool autoBounds = true) : base(corner1, corner1) {
        Font = font;
        AutoBounds = autoBounds;
        Align(alignment);
    }
    public TextUIElement(Point corner1, Point corner2, SpriteFont font, Alignment alignment = Alignment.LEFT) : base(corner1, corner2) {
        Font = font;
        Align(alignment);
    }
    
    public override void Draw(SpriteBatch spriteBatch) {
        base.Draw(spriteBatch);
        align();
        spriteBatch.DrawString(Font, Text, screenSpaceBounds.Item1.ToVector2(), Color, 0, origin, pixelScaleMultiplier * UNIVERSAL_TEXT_SCALE_MULTIPLIER, SpriteEffects.None, 0);
    }
    
    public void Align(Alignment alignment) {
        CurrentAlignment = alignment;
        switch (alignment){
            case Alignment.LEFT:
                AlignLeft();
                break;
            case Alignment.RIGHT:
                AlignRight();
                break;
            case Alignment.CENTER:
                AlignCenter();
                break;
        }
    }

    protected override void UpdateBounds() {
        Point inSpaceOrigin = Bounds.Item1 + origin.ToPoint();
        _bounds = ((Bounds.Item1 - inSpaceOrigin).MultiplyByScalar(ScaleMultiplier) + inSpaceOrigin, (Bounds.Item2 - Bounds.Item1).MultiplyByScalar(ScaleMultiplier) + inSpaceOrigin);
        screenSpaceBounds = (Bounds.Item1.MultiplyByScalar(pixelScaleMultiplier), Bounds.Item2.MultiplyByScalar(pixelScaleMultiplier));
        Align(CurrentAlignment);
    }
    
    public Vector2 Measure() => Font.MeasureString(Text) * UNIVERSAL_TEXT_SCALE_MULTIPLIER * ScaleMultiplier;
    
    private void AlignLeft() {
        align = () => origin = Vector2.Zero;
    }
    private void AlignRight() {
        align = () => origin = Font.MeasureString(Text) * ScaleMultiplier;
    }
    private void AlignCenter() {
        align = () => origin = new(Font.MeasureString(Text).X * ScaleMultiplier / 2, 0);
    }

    private Action align;

    public enum Alignment {
        LEFT, RIGHT, CENTER
    }
}