using System.Collections;
using System.Collections.Generic;
using Unity.VisualScripting;
using UnityEngine;

public class MapBuilding : MonoBehaviour
{
    [Tooltip("地图SO数据")] public HomeMapSO SO_HomeMap;
    [Tooltip("坐标起始点")] public GameObject startPositionObject;
    [Tooltip("可建造区域单元格的预制件")] public GameObject promptAreaPrefab;
    [Tooltip("测试房间")] public GameObject testRoomPrefab;
    public int cellSize = 2;

    // private function 
    private void create_direction_grid()
    {
        // 需要创建格子的坐标
        List<Vector2Int> neighbor_position_list = new List<Vector2Int>();
        // 方向列表：上下左右
        List<Vector2Int> direction_list = new List<Vector2Int>
        {
            new Vector2Int(1, 0), // 右
            new Vector2Int(0, 1), // 上 
            new Vector2Int(-1, 0), // 左
            new Vector2Int(0, -1) // 下
        };
        // 收集已有房间的格子坐标
        List<Vector2Int> has_room_position_list = SO_HomeMap.get_position_by_has_room();

        // 从已有房间的坐标推导出方向坐标列表
        foreach (var hr_position in has_room_position_list)
        {
            foreach (var dir_position in direction_list)
            {
                var neighbor_position = hr_position + dir_position;
                if (neighbor_position.x >= 1) continue; // 地面上的空间不生成
                if (!has_room_position_list.Contains(neighbor_position))
                {
                    neighbor_position_list.Add(neighbor_position);
                }
            }
        }

        // 生成四周的空间预制件
        foreach (var _position in neighbor_position_list)
        {
            GameObject room = Instantiate<GameObject>(
                promptAreaPrefab,
                position: (startPositionObject.transform.position +
                           new Vector3(_position.y, _position.x, 0) * cellSize),
                rotation: Quaternion.identity);
            Transform neighbor_container = startPositionObject.transform.Find("neighborContainer");
            room.name = $"Cell_{_position.x}.{_position.y}";
            room.transform.SetParent(neighbor_container);
        }
    }

    // 生成跟随鼠标移动的建筑物
    private void create_room_follow_mouse()
    {
        Vector3 mouse_world_position = Camera.main.ScreenToWorldPoint(Input.mousePosition);
        mouse_world_position.z = 0;

        GameObject current_test_room = Instantiate(testRoomPrefab,
            mouse_world_position, Quaternion.identity);
        current_test_room.name = "BuildingPreview";
        current_test_room.transform.SetParent(startPositionObject.transform);

        // 挂在脚本
        var placer = current_test_room.AddComponent<MapBuildPlacer>();
        placer.SO_HomeMap = SO_HomeMap;
        placer.startPositionObject = startPositionObject;
        placer.cellSize = cellSize;
    }

    // UI function 
    public void m_button_start_build()
    {
        create_direction_grid();
        create_room_follow_mouse();
    }
}