using System;
using UnityEngine;
using UnityEngine.Events;

namespace KhawajjaGames.Mobile
{
    /// <summary>
    /// Multi-touch Mobile Gesture & Swipe Controller for Unity Android and iOS.
    /// Handles 4-directional/8-directional swipes, taps, double-taps, and pinch-to-zoom.
    /// Created by Khawajja Games Studio (https://khawajjagames.com)
    /// </summary>
    public class MobileSwipeController : MonoBehaviour
    {
        public enum SwipeDirection { None, Left, Right, Up, Down, UpLeft, UpRight, DownLeft, DownRight }

        [Header("Swipe Thresholds")]
        [Tooltip("Minimum pixel distance required to register a swipe gesture")]
        public float minSwipeDistance = 50f;
        [Tooltip("Maximum duration in seconds for a quick flick swipe")]
        public float maxSwipeTime = 0.5f;

        [Header("Tap Settings")]
        public float doubleTapMaxDelay = 0.3f;

        [Header("Events")]
        public UnityEvent<SwipeDirection> OnSwipeDetected;
        public UnityEvent OnTap;
        public UnityEvent OnDoubleTap;
        public UnityEvent<float> OnPinchZoom; // Returns zoom delta

        private Vector2 _fingerDownPosition;
        private Vector2 _fingerUpPosition;
        private float _fingerDownTime;
        private float _lastTapTime;
        private float _initialPinchDistance;

        private void Update()
        {
            HandleTouchInput();
        }

        private void HandleTouchInput()
        {
            // Single Touch Handling (Tap, Double Tap, Swipe)
            if (Input.touchCount == 1)
            {
                Touch touch = Input.GetTouch(0);

                if (touch.phase == TouchPhase.Began)
                {
                    _fingerDownPosition = touch.position;
                    _fingerUpPosition = touch.position;
                    _fingerDownTime = Time.time;
                }
                else if (touch.phase == TouchPhase.Moved)
                {
                    _fingerUpPosition = touch.position;
                }
                else if (touch.phase == TouchPhase.Ended)
                {
                    _fingerUpPosition = touch.position;
                    float duration = Time.time - _fingerDownTime;
                    float distance = Vector2.Distance(_fingerDownPosition, _fingerUpPosition);

                    if (distance >= minSwipeDistance && duration <= maxSwipeTime)
                    {
                        DetectSwipeDirection();
                    }
                    else if (distance < minSwipeDistance)
                    {
                        DetectTap();
                    }
                }
            }
            // Dual Touch Handling (Pinch to Zoom)
            else if (Input.touchCount == 2)
            {
                Touch touchZero = Input.GetTouch(0);
                Touch touchOne = Input.GetTouch(1);

                Vector2 touchZeroPrevPos = touchZero.position - touchZero.deltaPosition;
                Vector2 touchOnePrevPos = touchOne.position - touchOne.deltaPosition;

                float prevTouchDeltaMag = (touchZeroPrevPos - touchOnePrevPos).magnitude;
                float touchDeltaMag = (touchZero.position - touchOne.position).magnitude;

                float deltaMagnitudeDiff = prevTouchDeltaMag - touchDeltaMag;

                OnPinchZoom?.Invoke(deltaMagnitudeDiff);
            }
        }

        private void DetectSwipeDirection()
        {
            Vector2 direction = _fingerUpPosition - _fingerDownPosition;
            float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg;
            if (angle < 0) angle += 360f;

            SwipeDirection swipe = SwipeDirection.None;

            if (angle >= 337.5f || angle < 22.5f) swipe = SwipeDirection.Right;
            else if (angle >= 22.5f && angle < 67.5f) swipe = SwipeDirection.UpRight;
            else if (angle >= 67.5f && angle < 112.5f) swipe = SwipeDirection.Up;
            else if (angle >= 112.5f && angle < 157.5f) swipe = SwipeDirection.UpLeft;
            else if (angle >= 157.5f && angle < 202.5f) swipe = SwipeDirection.Left;
            else if (angle >= 202.5f && angle < 247.5f) swipe = SwipeDirection.DownLeft;
            else if (angle >= 247.5f && angle < 292.5f) swipe = SwipeDirection.Down;
            else if (angle >= 292.5f && angle < 337.5f) swipe = SwipeDirection.DownRight;

            OnSwipeDetected?.Invoke(swipe);
        }

        private void DetectTap()
        {
            float timeSinceLastTap = Time.time - _lastTapTime;

            if (timeSinceLastTap <= doubleTapMaxDelay)
            {
                OnDoubleTap?.Invoke();
                _lastTapTime = 0f;
            }
            else
            {
                OnTap?.Invoke();
                _lastTapTime = Time.time;
            }
        }
    }
}