using UnityEngine;
using UnityEngine.InputSystem;

namespace DanieleMarotta.RiversongCodeShowcase
{
    public class TerrainShaderDebugGUI : MonoBehaviour
    {
        private const int GUIRectWidth = 500;

        private bool _drawGUI;

        public Texture2D BlockedTilesMaskTexture { get; set; }

        public Texture2D CliffsMaskTexture { get; set; }

        public static TerrainShaderDebugGUI Create()
        {
            return new GameObject(nameof(TerrainShaderDebugGUI)).AddComponent<TerrainShaderDebugGUI>();
        }

        private void Update()
        {
            if (Keyboard.current.f1Key.wasPressedThisFrame) _drawGUI = !_drawGUI;
        }

        private void OnGUI()
        {
            if (!_drawGUI) return;

            GUI.color = new Color(1, 1, 1, 0.8f);

            var x = 0;
            DrawTexture(BlockedTilesMaskTexture, ref x);
            DrawTexture(CliffsMaskTexture, ref x);
        }

        private void DrawTexture(Texture2D texture, ref int x)
        {
            const int spacing = 10;

            var oldFilterMode = texture.filterMode;
            texture.filterMode = FilterMode.Point;

            var aspect = (float)texture.height / texture.width;
            GUI.DrawTexture(new Rect(spacing + x, spacing, GUIRectWidth, GUIRectWidth * aspect), texture, ScaleMode.ScaleToFit, false);

            texture.filterMode = oldFilterMode;

            x += GUIRectWidth + spacing;
        }
    }
}