using UnityEngine;

public class SmoothMoveToGPSLocation : MonoBehaviour
{
    public int targetZoom = 18;
    public float animationDuration = 5; // sec
    public AnimationCurve movementCurve = AnimationCurve.Linear(0, 0, 1, 1);
    public AnimationCurve zoomCurve = AnimationCurve.Linear(0, 0, 1, 1);

    private bool animationStarted = false;
    private Vector2 startLocation;
    private double startTileX;
    private double startTileY;
    private Vector2 endLocation;
    private double endTileX;
    private double endTileY;
    private int startZoom;

    private float progress;
    private OnlineMaps map;
    private Vector3 initialPosition;

    private void Start()
    {
        map = OnlineMaps.instance;
        OnlineMapsLocationService.instance.OnLocationInited += OnLocationInited;
    }

    private void OnLocationInited()
    {
        startZoom = map.zoom;
        startLocation = map.position;
        endLocation = OnlineMapsLocationService.instance.position;

        map.projection.CoordinatesToTile(startLocation.x, startLocation.y, 20, out startTileX, out startTileY);
        map.projection.CoordinatesToTile(endLocation.x, endLocation.y, 20, out endTileX, out endTileY);
        int mx = 1 << 20;
        if (Mathf.Abs((float) (endTileX - startTileY)) > mx / 2)
        {
            if (endTileX > startTileY) endTileY -= mx;
            else endTileY += mx;
        }

        initialPosition = map.transform.position;
        OnlineMapsControlBase.instance.allowUserControl = false;
        animationStarted = true;
    }

    private void Update()
    {
        if (!animationStarted) return;

        UpdateProgress();
        UpdateZoom();
        UpdatePosition();
    }

    private void UpdatePosition()
    {
        float f = movementCurve.Evaluate(progress);
        double cx = Mathf.Lerp((float)startTileX, (float)endTileX, f);
        double cy = Mathf.Lerp((float)startTileY, (float)endTileY, f);
        int mx = 1 << 20;
        if (cx < 0) cx += mx;
        else if (cx > mx) cx -= mx;
        map.projection.TileToCoordinates(cx, cy, 20, out cx, out cy);
        map.SetPosition(cx, cy);
    }

    private void UpdateZoom()
    {
        float z = Mathf.Lerp(startZoom, targetZoom, zoomCurve.Evaluate(progress));
        map.zoom = (int) z;
        float v = z - (int) z;
        float v1 = v + 1;
        map.transform.localScale = new Vector3(v1, v1, v1);
        Vector3 p = new Vector3(-v * map.tilesetSize.x / 2, 0, v * map.tilesetSize.y / 2);
        map.transform.localPosition = initialPosition - p;
    }

    private void UpdateProgress()
    {
        progress += Time.deltaTime / animationDuration;
        if (progress >= 1)
        {
            animationStarted = false;
            progress = 1;
            OnlineMapsControlBase.instance.allowUserControl = true;
        }
    }
}