using UnityEngine;
using System.Collections;

public class Block : MonoBehaviour
{
    public GridPos Position; // Our current grid position

    private const float moveTime = 0.2f;
    private bool isMoving;

    void Update()
    {
        if (Position.Y > 0 && Map.Instance.Layout[Position+GridPos.Down] == null && !isMoving) // Are we above the first cell in our column, is the cell below us unoccupied and we are not currently moving?
        {
            StartCoroutine(MoveDown()); // Begin moving one cell down
        }
    }

    public void Matched()
    {
        Map.Instance.Layout[Position] = null; // Set our current position as occupied
        Destroy(gameObject); // Destroy this block
    }

    IEnumerator MoveDown()
    {
        isMoving = true; // We're moving!

        GridPos endPosGrid = new GridPos(Position.X, Position.Y-1);
        Vector3 startPos = transform.position;
        Vector3 endPos = Map.Instance.GridToWorld(endPosGrid);

        Map.Instance.Layout[Position] = null; // Mark our current position as unoccupied
        Map.Instance.Layout[endPosGrid] = this; // Mark our new position as occupied
        Position = endPosGrid;

        // Visually move to our new position over a set time
        float t = 0;
        while (t < moveTime)
        {
            transform.position = Vector3.MoveTowards(startPos, endPos, t/moveTime); // Lerp our position
            t += Time.deltaTime;
            yield return null;
        }

        transform.position = endPos; // Fix overshoot
        isMoving = false; // We're done moving
    }
}