using Friflo.Engine.ECS;
using Microsoft.Xna.Framework;
using MrGameEng.Graphics;

namespace MrGameEng.Tilemaps;

/// <summary>
/// Tilemap component: a <see cref="TileGrid"/> of ids drawn with a <see cref="TileSet"/>.
/// Cell (0,0) sits at <see cref="Origin"/>, cells are <see cref="TileSize"/> world units square.
/// Only the cells visible through the camera are submitted each frame, so grids can be large.
/// Create via the constructor — the struct default has no grid and draws nothing.
/// </summary>
public struct Tilemap : IComponent
{
    /// <summary>Tile definitions; ids in the grid index into it.</summary>
    public TileSet? TileSet;

    /// <summary>The cells. Mutating ids takes effect next frame.</summary>
    public TileGrid? Grid;

    /// <summary>World position of the top-left corner of cell (0,0).</summary>
    public Vector2 Origin;

    /// <summary>Cell size in world units.</summary>
    public float TileSize;

    /// <summary>Render layer of the whole map.</summary>
    public LayerId Layer;

    /// <summary>Draw order within the layer (smaller = drawn first / behind).</summary>
    public float Depth;

    /// <summary>Tint multiplied into every tile on top of its <see cref="TileDef.Color"/>.</summary>
    public Color Color;

    /// <summary>Creates a tilemap at world origin.</summary>
    public Tilemap(TileGrid grid, TileSet tileSet, float tileSize, LayerId layer = default)
    {
        Grid = grid;
        TileSet = tileSet;
        TileSize = tileSize;
        Layer = layer;
        Origin = Vector2.Zero;
        Depth = 0f;
        Color = Color.White;
    }
}