using UnityEngine;
using UnityEngine.EventSystems;

/// <summary>
/// Touch/click region that drives one gameplay track (0-4) through InputManager,
/// exactly as if the bound keyboard key were pressed/released. Attach to a UI
/// element (Image with Raycast Target on) laid over a lane; set trackIndex in the
/// inspector. Uses EventSystem pointer callbacks so it supports multi-touch (each
/// finger routes its own down/up to the region it started on) and works on Android
/// touch as well as desktop mouse.
///
/// Judgment/scoring is unchanged: this only injects the same press/release the
/// keyboard path produces. On a track already held by keyboard, PressTrack/
/// ReleaseTrack are idempotent so there is no double-trigger.
/// </summary>
[RequireComponent(typeof(RectTransform))]
public class TrackTouchRegion : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
    [Tooltip("Track this region controls: 0=red 1=green 2=yellow 3=purple 4=blue")]
    [Range(0, 4)]
    public int trackIndex = 0;

    // The pointerId that pressed this region, so we only release on the matching
    // pointer's up event (relevant for multi-touch where several fingers are down).
    private int activePointerId = int.MinValue;
    private bool pressed = false;

    public void OnPointerDown(PointerEventData eventData)
    {
        if (pressed) return; // already driven by another finger; ignore extras
        var im = InputManager.Instance;
        if (im == null) return;

        activePointerId = eventData.pointerId;
        pressed = true;
        im.PressTrack(trackIndex);
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        if (!pressed || eventData.pointerId != activePointerId) return;
        var im = InputManager.Instance;

        pressed = false;
        activePointerId = int.MinValue;
        if (im != null) im.ReleaseTrack(trackIndex);
    }

    private void OnDisable()
    {
        // If the region is hidden/destroyed mid-hold, make sure the track is released
        // so a note is not left stuck in the held state.
        if (pressed)
        {
            pressed = false;
            activePointerId = int.MinValue;
            var im = InputManager.Instance;
            if (im != null) im.ReleaseTrack(trackIndex);
        }
    }
}