using System;
using System.IO;
using System.Linq;
using UnityEditor;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace BitGames.Terrain
{
  [CustomEditor(typeof(TerrainFloorRenderer))]
  public class TerrainFloorRendererEditor : Editor
  {
    private SerializedProperty _asset;
    private TerrainFloorRenderer _target => target as TerrainFloorRenderer;
    private static readonly string[] _textureSizeOptions = RuntimeGlobals.SizeOptions.Select(x => $"{x.TextureSize}x{x.TextureSize}").ToArray();
    private int _textureSizeOption = 1;

    private void OnEnable()
    {
      _asset = serializedObject.FindProperty(nameof(TerrainFloorRenderer.Asset));
      _target.HideMeshFilterRenderer();
    }

    public override void OnInspectorGUI()
    {
      serializedObject.Update();
      EditorGUILayout.PropertyField(_asset);

      if (_target.Asset != null)
        RenderEditGUI();
      else
        RenderCreateGUI();
    }

    private void RenderEditGUI()
    {

    }

    private void RenderCreateGUI()
    {
      _textureSizeOption = EditorGUILayout.Popup("Size:", _textureSizeOption, _textureSizeOptions);
      if (GUILayout.Button("Create Terrain Asset"))
      {
        CreateAsset();
        _target.OnValidate();
      }
    }

    private SizeOption GetSizeOption()
    {
      var options = RuntimeGlobals.SizeOptions;
      return options[Math.Clamp(_textureSizeOption, 0, options.Length - 1)];
    }

    void CreateAsset()
    {
      Scene scene = _target.gameObject.scene;
      var scenePath = Path.GetDirectoryName(scene.path);
      if (string.IsNullOrEmpty(scenePath))
        scenePath = Application.dataPath;

      var sceneName = scene.name;
      if (string.IsNullOrEmpty(sceneName))
        sceneName = "SceneFloorMap";

      var path = EditorUtility.SaveFilePanel(
        "Save terrain asset",
        scenePath,
        sceneName + "_Terrain.asset",
        "asset");

      var relativePath = Path.GetRelativePath(".", path);

      if (path.Length == 0)
        return;

      _target.Asset = TerrainAsset.Create(relativePath, GetSizeOption().TextureSize);
    }
  }
}