// Author: fruit.com.cn

import 'dart:async';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

import 'player_double_tap_hearts.dart';
import 'player_heart_overlay_scope.dart';

typedef PlayerLongPressStartCallback =
    void Function(LongPressStartDetails details, double width);

/// 播放画面共用的单击/双击仲裁层。
class PlayerTapGestureRegion extends StatefulWidget {
  const PlayerTapGestureRegion({
    super.key,
    required this.gestureKey,
    required this.onSingleTap,
    required this.onLongPressStart,
    required this.onInteractionEnd,
    this.onDoubleTapLike,
    this.doubleTapEnabled = true,
    this.enabled = true,
    this.now,
  });

  final Key gestureKey;
  final VoidCallback onSingleTap;
  final ValueChanged<Offset>? onDoubleTapLike;
  final PlayerLongPressStartCallback onLongPressStart;
  final VoidCallback onInteractionEnd;
  final bool doubleTapEnabled;
  final bool enabled;
  final DateTime Function()? now;

  @override
  State<PlayerTapGestureRegion> createState() => _PlayerTapGestureRegionState();
}

class _PlayerTapGestureRegionState extends State<PlayerTapGestureRegion> {
  static const Duration _singleTapDelay = Duration(milliseconds: 240);

  Timer? _singleTapTimer;
  DateTime? _lastDownAt;
  DateTime? _blockSingleTapUntil;
  bool _doubleTapDown = false;
  bool _likedThisPair = false;
  int _downSerial = 0;
  int _tapSeq = 0;
  int _nextHeartBurstId = 0;

  @override
  void dispose() {
    _tapSeq++;
    _singleTapTimer?.cancel();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return IgnorePointer(
      ignoring: !widget.enabled,
      child: LayoutBuilder(
        builder: (context, constraints) => Listener(
          onPointerUp: (_) => widget.onInteractionEnd(),
          onPointerCancel: (_) => widget.onInteractionEnd(),
          onPointerDown: _handlePointerDown,
          child: Stack(
            fit: StackFit.expand,
            clipBehavior: Clip.none,
            children: [
              GestureDetector(
                key: widget.gestureKey,
                behavior: HitTestBehavior.opaque,
                onTapUp: _handleTapUp,
                onLongPressStart: (details) =>
                    _handleLongPressStart(details, constraints.maxWidth),
                onLongPressEnd: (_) => widget.onInteractionEnd(),
                onLongPressCancel: widget.onInteractionEnd,
              ),
            ],
          ),
        ),
      ),
    );
  }

  DateTime _now() => widget.now?.call() ?? DateTime.now();

  void _handlePointerDown(PointerDownEvent event) {
    final now = _now();
    final previous = _lastDownAt;
    _downSerial++;
    _lastDownAt = now;
    final repeated =
        previous != null && now.difference(previous) <= _singleTapDelay;
    if (!repeated) {
      if (_singleTapBlocked(now)) return;
      _doubleTapDown = false;
      _likedThisPair = false;
      return;
    }
    _doubleTapDown = true;
    _blockSingleTapUntil = now.add(_singleTapDelay);
    _cancelPendingSingleTap();
  }

  bool _singleTapBlocked(DateTime now) {
    final blockedUntil = _blockSingleTapUntil;
    return blockedUntil != null && now.isBefore(blockedUntil);
  }

  void _cancelPendingSingleTap() {
    _tapSeq++;
    _singleTapTimer?.cancel();
    _singleTapTimer = null;
  }

  void _handleTapUp(TapUpDetails details) {
    final now = _now();
    if (_doubleTapDown || _singleTapBlocked(now)) {
      _handleDoubleTapLike(details.globalPosition);
      return;
    }
    final serial = _downSerial;
    final tapSeq = ++_tapSeq;
    _singleTapTimer?.cancel();
    late final Timer pending;
    pending = Timer(_singleTapDelay, () {
      if (!identical(_singleTapTimer, pending)) return;
      _singleTapTimer = null;
      if (!mounted || tapSeq != _tapSeq || serial != _downSerial) return;
      if (_doubleTapDown || _singleTapBlocked(_now())) return;
      _lastDownAt = null;
      widget.onSingleTap();
    });
    _singleTapTimer = pending;
  }

  void _handleDoubleTapLike(Offset globalPosition) {
    _blockSingleTapUntil = _now().add(_singleTapDelay);
    _cancelPendingSingleTap();
    if (!widget.doubleTapEnabled || _likedThisPair) return;
    _likedThisPair = true;
    _showHeartBurst(globalPosition);
    widget.onDoubleTapLike?.call(globalPosition);
  }

  void _showHeartBurst(Offset globalPosition) {
    final overlay = Overlay.maybeOf(context, rootOverlay: true);
    if (overlay == null) return;
    final overlayBox = overlay.context.findRenderObject();
    final origin = overlayBox is RenderBox
        ? overlayBox.globalToLocal(globalPosition)
        : globalPosition;
    final id = _nextHeartBurstId++;
    final controller = PlayerHeartOverlayScope.maybeOf(context);
    var removed = false;
    late final OverlayEntry entry;
    void removeEntry() {
      if (removed) return;
      removed = true;
      controller?.untrack(id);
      if (entry.mounted) entry.remove();
      entry.dispose();
      if (kDebugMode) {
        debugPrint('[player] phase=heart-burst-entry-removed id=$id');
      }
    }

    entry = OverlayEntry(
      builder: (context) => Positioned.fill(
        child: IgnorePointer(
          child: PlayerDoubleTapHeartBurst(
            key: ValueKey('heart-overlay-$id'),
            burstId: id,
            origin: origin,
            now: widget.now,
            onCompleted: removeEntry,
          ),
        ),
      ),
    );
    controller?.track(id, entry);
    overlay.insert(entry);
  }

  void _handleLongPressStart(LongPressStartDetails details, double width) {
    _tapSeq++;
    _cancelPendingSingleTap();
    _doubleTapDown = false;
    _lastDownAt = null;
    widget.onLongPressStart(details, width);
  }
}