using System;
using System.Collections;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;
using UnityEngine.Events;

public class Environment : MonoBehaviour
{
    private static Environment instance;

    private Dictionary<string, Block> blockRegistry = new Dictionary<string, Block>();

    public UnityEvent<Block> onBlockAddedEvent;
    public UnityEvent<Block, Vector3, Quaternion> onBlockMovedEvt;
    public UnityEvent<Block> onBlockRemovedEvent;
    public UnityEvent onChangeEvent;

    public static Environment getInstance()
    {
        if (instance == null)
        {
            instance = FindObjectOfType<Environment>();
            if (instance == null)
            {
                GameObject environmentObject = new GameObject("Environment");
                instance = environmentObject.AddComponent<Environment>();
            }
        }
        return instance;
    }

    public Dictionary<String, Block> getBlockRegistry()
    {
        return blockRegistry;
    }

    private void Awake()
    {
        if (instance == null)
        {
            instance = this;
        }
        else
        {
            Destroy(gameObject);
        }
    }

    public void addBlock(Block block, string existingUUID = null)
    {
        // 1. Assign ID: Use existing (Undo/Redo) or generate a new one (Fresh placement)
        string uuid = string.IsNullOrEmpty(existingUUID) ? Guid.NewGuid().ToString() : existingUUID;

        block.setBlockId(uuid);

        // 2. Register in the dictionary
        if (!blockRegistry.ContainsKey(uuid))
        {
            blockRegistry.Add(uuid, block);
        }
        else
        {
            blockRegistry[uuid] = block; // Update reference if already exists
        }
        applyChanges();
        onBlockAddedEvent.Invoke(block);
    }

    public void moveBlock(Block block, Vector3 oldPos, Quaternion oldRot, Vector3 newPos, Quaternion newRot)
    {
        block.transform.SetPositionAndRotation(newPos, newRot);
        onBlockMovedEvt.Invoke(block, oldPos, oldRot);
        applyChanges();
    }

    public void removeBlock(string uuid)
    {
        if (blockRegistry.TryGetValue(uuid, out Block block))
        {
            onBlockRemovedEvent.Invoke(block);
            blockRegistry.Remove(uuid);
            applyChanges();
        }
    }

    public void applyChanges()
    {
        onChangeEvent.Invoke();
    }
    public void completeDestroyBlock(Block block)
    {
        if (block != null)
            Destroy(block.gameObject);
    }

    public Block getBlock(string uuid)
    {
        if (blockRegistry.TryGetValue(uuid, out Block block))
        {
            return block;
        }
        return null;
    }

    public void clearEnvironment()
    {
        foreach (var blockEntry in blockRegistry)
        {
            if (blockEntry.Value != null)
            {
                Destroy(blockEntry.Value.gameObject);
            }
        }
        blockRegistry.Clear();
    }
}