using System.Collections.Generic;
using Ichni;
using TMPro;
using UnityEngine;

[RequireComponent(typeof(MeshFilter), typeof(MeshRenderer))]
public class SimpleGridController : MonoBehaviour
{
    public Camera targetCamera => EditorManager.instance.cameraManager.currentCamera;

    [Header("Settings")]
    public Material gridMaterial;
    public GameObject textPrefab; // 预制体需要挂载 TextMeshPro
    public Transform textParent;

    [Header("Grid Logic")]
    public bool showCoordinates = true;
    public float baseGridSize = 1.0f;
    [Range(10f, 1000f)] public float drawDistance = 100f;


    // --- 内部状态 ---
    private MeshRenderer _renderer;
    private Material _instancedMat;
    private float _currentSpacing = 1.0f;

    void Start()
    {

        InitMesh();

        _renderer = GetComponent<MeshRenderer>();
        if (gridMaterial)
        {
            _instancedMat = new Material(gridMaterial);
            _renderer.material = _instancedMat;
        }


    }

    void LateUpdate()
    {
        if (!targetCamera) return;

        Vector3 camPos = targetCamera.transform.position;

        // 1. 网格跟随相机 (无限大地板)
        transform.position = new Vector3(camPos.x, 0, camPos.z);

        // 2. 计算层级 (1m / 10m / 100m)
        CalculateGridLevel(camPos.y);

        // 3. 更新 Shader
        if (_instancedMat)
        {
            _instancedMat.SetFloat("_GridSpacing", _currentSpacing);
            _instancedMat.SetFloat("_FadeDist", drawDistance);
        }


    }

    private void CalculateGridLevel(float camHeight)
    {
        float absH = Mathf.Abs(camHeight);
        float step = baseGridSize;

        // 简单的自适应逻辑：根据高度决定网格密度
        if (absH > 15f) step *= 10f;
        if (absH > 150f) step *= 10f;

        _currentSpacing = step;
    }


    private void InitMesh()
    {
        MeshFilter mf = GetComponent<MeshFilter>();
        Mesh mesh = new Mesh();
        // 覆盖视野的大 Quad
        float size = 2000f;
        Vector3[] vertices = new Vector3[4]
        {
            new Vector3(-size, 0, -size), new Vector3(size, 0, -size),
            new Vector3(-size, 0, size), new Vector3(size, 0, size)
        };
        mesh.vertices = vertices;
        mesh.triangles = new int[6] { 0, 2, 1, 2, 3, 1 };
        mesh.uv = new Vector2[4] { Vector2.zero, Vector2.right, Vector2.up, Vector2.one };
        mesh.RecalculateBounds();
        mf.mesh = mesh;
    }
}