using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;

public class tetromino : MonoBehaviour
{
    public float timeBetweenSteps;
    public bool active = true;
    private tetrominoUserControl TetrominoUserControl;
    private tetrominoSpawnManager TetrominoSpawnManager;
    
    private float stepTimer = 0.0f;
    private bool wouldCollide = false;

    // Start is called before the first frame update
    void Start()
    {
        TetrominoSpawnManager = FindObjectOfType<tetrominoSpawnManager>();
        TetrominoUserControl = FindObjectOfType<tetrominoUserControl>();
        TetrominoUserControl.setActiveTetromino(gameObject);
    }

    // Update is called once per frame
    void Update()
    {
        stepTimer += Time.deltaTime;

        if (stepTimer >= timeBetweenSteps && active)
        {
            stepTimer = stepTimer - timeBetweenSteps;
            nextStep();
        }
        
    }

    void nextStep()
    {
        //I want to run this for each piece of the tetromino.
        foreach (Transform child in transform)
        {
            //Only do this if it's a piece at the bottom, so we don't detect ourself as a collision.
            if (Math.Abs(child.localPosition.y - (0.5)) < 0.001) //my IDE suggested I do this to fix floating-point comparison issues, and I see the logic at work here.
            {
                if (validateFall(child))
                {
                    wouldCollide = true;
                    break;
                }
            }
        }
        
        if (wouldCollide == false)
        {
            Fall();
        }
        else
        {
            GetComponent<AudioSource>().Play();
            active = false;
            TetrominoUserControl.unsetActiveTetromino();
            TetrominoSpawnManager.spawnTetromino();
        }
    }

    private bool validateFall(Transform pieceToCheck) //returns true if the next step collides with something
    {
        //Cast a ray to the next position of the tetromino. 
        //NOTE: disabled "Queries Start in Colliders" in Project Settings>Physics 2D (thank you again, Tavi).
        RaycastHit2D collision = Physics2D.Raycast(pieceToCheck.position, Vector2.down, 1.0f);
        // Debug.DrawRay(pieceToCheck.position,Vector3.down,Color.red,1000.0f);
        if (collision.collider != null && collision.collider.name != pieceToCheck.name)
        {
            Debug.Log("Collided with object: " + collision.collider.name);
            //We hit something, but what?
            if (collision.collider.CompareTag("Ground") || collision.collider.CompareTag("Tetromino"))
            {
                ScoreCounter.scoreAmount += 100;
                return true;
            }
            return true;
        }

        return false;
    }

    void Fall()
    {
        transform.position += Vector3.down * 1.0f;
    }
}