using UnityEngine;
using UnityEngine.EventSystems;

namespace BrewMonster.UI
{
    public class WorldMapClickHandler : MonoBehaviour, IPointerClickHandler
    {
        [Tooltip("The RectTransform of the Map Image (Usually this GameObject)")]
        private RectTransform mapRectTransform;

        [SerializeField] private RectTransform _hostPlayerPositionImage;

        public DlgWorldMap dlgWorldMap;

        // if true, user can click on the map to move the host player to the clicked position. 
        // ideally we only enble this for testing/development.
        [SerializeField] private bool _enableClickToMove = true;

        // The host player player (0,0,0) is not at the center of the map. It usually has an offset that we have to calculate at Awake
        private Vector2 _hostPlayerOffsetPosition;

        private void Awake()
        {
            // Get the RectTransform of the map
            mapRectTransform = GetComponent<RectTransform>();

            CalculateHostPlayerOffsetPosition();
        }

        private void CalculateHostPlayerOffsetPosition()
        {
            _hostPlayerOffsetPosition = _hostPlayerPositionImage.anchoredPosition;
            
            // if the max/min of the anchor is 0.5 0.5, then the host player is at the center of the map
            // however we have to calculate the offset of the player because it is not at the center of the map
            // we can calculate the offset by the max/min of the anchor
            var maxAnchor = _hostPlayerPositionImage.anchorMax;
            var minAnchor = _hostPlayerPositionImage.anchorMin;
            _hostPlayerOffsetPosition = new Vector2((maxAnchor.x - 0.5f) * mapRectTransform.rect.width, (maxAnchor.y - 0.5f) * mapRectTransform.rect.height);
        }

        // This triggers automatically when the user clicks/taps on this Image
        public void OnPointerClick(PointerEventData eventData)
        {
            if(!_enableClickToMove) return;
            
            Vector2 localCursorPosition;

            // Convert the screen click position to local anchored position inside the Map
            bool isConverted = RectTransformUtility.ScreenPointToLocalPointInRectangle(
                mapRectTransform, 
                eventData.position, 
                eventData.pressEventCamera, 
                out localCursorPosition
            );

            if (isConverted)
            {
                // convert the localCursorPosition to the local position of the host player position image
                localCursorPosition -= _hostPlayerOffsetPosition;
                dlgWorldMap.OnMapClicked(localCursorPosition);
            }
        }
    }
}