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

import 'package:social_app/core/theme/design_tokens.dart';
import 'package:social_app/shared/widgets/app_button.dart';
import 'package:social_app/features/calendar/reminders/reminder_queue_manager.dart';
import 'package:social_app/features/calendar/reminders/models/reminder_payload.dart';

class ReminderOverlay extends StatelessWidget {
  const ReminderOverlay({
    super.key,
    required this.queueManager,
    required this.onComplete,
    required this.onSnooze,
    required this.onArchive,
  });

  final ReminderQueueManager queueManager;
  final VoidCallback onComplete;
  final void Function(int minutes) onSnooze;
  final VoidCallback onArchive;

  @override
  Widget build(BuildContext context) {
    final payload = queueManager.currentPayload;

    return Scaffold(
      backgroundColor: AppColors.white,
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: AppSpacing.lg),
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.center,
            children: [
              const Spacer(),
              Text(
                payload?.title ?? '',
                style: Theme.of(context).textTheme.headlineSmall,
                textAlign: TextAlign.center,
              ),
              const SizedBox(height: AppSpacing.md),
              Text(
                DateFormat('HH:mm').format(DateTime.now()),
                style: Theme.of(context).textTheme.titleLarge,
              ),
              const Spacer(),
              _buildBottomButtons(context),
              const SizedBox(height: AppSpacing.xxl),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildBottomButtons(BuildContext context) {
    return Row(
      children: [
        Expanded(
          child: _SnoozeButton(
            onSnooze: (minutes) {
              onSnooze(minutes);
              queueManager.dequeueCurrent();
              onComplete();
            },
          ),
        ),
        const SizedBox(width: AppSpacing.md),
        Expanded(
          child: AppButton(
            text: '完成',
            onPressed: () {
              onArchive();
              queueManager.dequeueCurrent();
              onComplete();
            },
          ),
        ),
      ],
    );
  }
}

class _SnoozeButton extends StatefulWidget {
  const _SnoozeButton({required this.onSnooze});

  final void Function(int minutes) onSnooze;

  @override
  State<_SnoozeButton> createState() => _SnoozeButtonState();
}

class _SnoozeButtonState extends State<_SnoozeButton> {
  final LayerLink _layerLink = LayerLink();
  OverlayEntry? _overlayEntry;

  @override
  void dispose() {
    _removeOverlay();
    super.dispose();
  }

  void _removeOverlay() {
    _overlayEntry?.remove();
    _overlayEntry = null;
  }

  void _showOverlay() {
    _removeOverlay();

    final overlay = Overlay.of(context);
    final renderBox = context.findRenderObject() as RenderBox;
    final size = renderBox.size;

    _overlayEntry = OverlayEntry(
      builder: (context) => Stack(
        children: [
          Positioned(
            width: size.width,
            child: CompositedTransformFollower(
              link: _layerLink,
              showWhenUnlinked: false,
              offset: Offset(0, size.height + AppSpacing.xs),
              child: Material(
                elevation: 4,
                borderRadius: BorderRadius.circular(AppRadius.md),
                color: AppColors.white,
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    _SnoozeOption(
                      label: '5 分钟',
                      onTap: () {
                        _removeOverlay();
                        widget.onSnooze(5);
                      },
                    ),
                    Divider(height: 1, color: AppColors.border),
                    _SnoozeOption(
                      label: '15 分钟',
                      onTap: () {
                        _removeOverlay();
                        widget.onSnooze(15);
                      },
                    ),
                  ],
                ),
              ),
            ),
          ),
          Positioned.fill(
            child: GestureDetector(
              onTap: _removeOverlay,
              behavior: HitTestBehavior.opaque,
              child: Container(color: Colors.transparent),
            ),
          ),
        ],
      ),
    );

    overlay.insert(_overlayEntry!);
  }

  @override
  Widget build(BuildContext context) {
    return CompositedTransformTarget(
      link: _layerLink,
      child: AppButton(
        text: '稍后提醒',
        isOutlined: true,
        onPressed: () {
          if (_overlayEntry == null) {
            _showOverlay();
          } else {
            _removeOverlay();
          }
        },
      ),
    );
  }
}

class _SnoozeOption extends StatelessWidget {
  const _SnoozeOption({required this.label, required this.onTap});

  final String label;
  final VoidCallback onTap;

  @override
  Widget build(BuildContext context) {
    return InkWell(
      onTap: onTap,
      borderRadius: BorderRadius.circular(AppRadius.md),
      child: Padding(
        padding: const EdgeInsets.symmetric(
          horizontal: AppSpacing.lg,
          vertical: AppSpacing.md,
        ),
        child: Text(
          label,
          style: const TextStyle(fontSize: 15, fontWeight: FontWeight.w500),
        ),
      ),
    );
  }
}