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

import '../core/theme.dart';

/// Seven-day selector. A dot under a day marks something booked or set.
class WeekStrip extends StatelessWidget {
  const WeekStrip({
    super.key,
    required this.days,
    required this.selected,
    required this.onSelect,
    this.marked = const {},
  });

  final List<DateTime> days;
  final DateTime selected;
  final ValueChanged<DateTime> onSelect;

  /// Day indices (0..6) that carry a marker dot.
  final Set<int> marked;

  @override
  Widget build(BuildContext context) {
    final dow = DateFormat('EEE');
    return Row(
      children: [
        for (var i = 0; i < days.length; i++) ...[
          if (i > 0) const SizedBox(width: 7),
          Expanded(
            child: _DayCell(
              day: days[i],
              label: dow.format(days[i]),
              selected:
                  days[i].day == selected.day &&
                  days[i].month == selected.month,
              marked: marked.contains(i),
              onTap: () => onSelect(days[i]),
            ),
          ),
        ],
      ],
    );
  }
}

class _DayCell extends StatelessWidget {
  const _DayCell({
    required this.day,
    required this.label,
    required this.selected,
    required this.marked,
    required this.onTap,
  });

  final DateTime day;
  final String label;
  final bool selected;
  final bool marked;
  final VoidCallback onTap;

  static const _duration = Duration(milliseconds: 260);
  static const _curve = Curves.easeOutCubic;

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: onTap,
      // Colour is animated rather than swapped so moving along the week reads
      // as one continuous selection rather than a series of flashes.
      child: AnimatedContainer(
        duration: _duration,
        curve: _curve,
        height: 64,
        decoration: BoxDecoration(
          color: selected ? KrowPalette.blue : Colors.white,
          borderRadius: BorderRadius.circular(12),
          border: Border.all(
            color: selected ? KrowPalette.blue : KrowPalette.line,
          ),
          boxShadow: selected
              ? [
                  BoxShadow(
                    color: KrowPalette.blue.withValues(alpha: 0.26),
                    blurRadius: 12,
                    offset: const Offset(0, 4),
                  ),
                ]
              : null,
        ),
        child: Stack(
          alignment: Alignment.center,
          children: [
            Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                AnimatedDefaultTextStyle(
                  duration: _duration,
                  curve: _curve,
                  style: TextStyle(
                    fontSize: 9,
                    fontWeight: FontWeight.w600,
                    letterSpacing: 0.8,
                    color: selected ? Colors.white70 : const Color(0xFF949FA5),
                  ),
                  child: Text(label.toUpperCase()),
                ),
                const SizedBox(height: 2),
                AnimatedDefaultTextStyle(
                  duration: _duration,
                  curve: _curve,
                  style: TextStyle(
                    fontSize: 16,
                    fontWeight: FontWeight.w700,
                    color: selected ? Colors.white : KrowPalette.ink,
                  ),
                  child: Text('${day.day}'),
                ),
              ],
            ),
            Positioned(
              bottom: 8,
              child: AnimatedScale(
                scale: marked ? 1 : 0,
                duration: _duration,
                curve: Curves.easeOutBack,
                child: AnimatedContainer(
                  duration: _duration,
                  width: 5,
                  height: 5,
                  decoration: BoxDecoration(
                    shape: BoxShape.circle,
                    color: selected ? KrowPalette.yellow : KrowPalette.blue,
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}