/// Refine a single pile — promote / demote cards (Important Cards pattern).
library;

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

import '../models/value_pile.dart';
import '../providers/values_sort_provider.dart';
import '../widgets/practice_chrome.dart';
import '../widgets/value_card_tile.dart';
import '../utils/app_theme.dart';

class PileReviewScreen extends StatelessWidget {
  const PileReviewScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final sort = context.watch<ValuesSortController>();
    final pile = sort.reviewPile ?? ValuePile.important;
    final cards = sort.cardsInPile(pile);
    final text = Theme.of(context).textTheme;
    final colors = Theme.of(context).colorScheme;

    return PracticeScaffold(
      header: Padding(
        padding: const EdgeInsets.fromLTRB(8, 4, 12, 0),
        child: Row(
          children: [
            IconButton(
              onPressed: sort.goToOverview,
              icon: const Icon(Icons.arrow_back),
            ),
            Expanded(
              child: Text(
                'Reviewing · ${pile.label}',
                style: text.labelMedium,
              ),
            ),
          ],
        ),
      ),
      footer: PrimaryPillButton(
        label: 'Back to overview',
        onPressed: sort.goToOverview,
      ),
      child: ListView(
        children: [
          Text(pile.label, style: text.displaySmall),
          const SizedBox(height: 6),
          Text(
            '${cards.length} values in this pile. Promote toward your core or demote when something feels less essential.',
            style: text.bodyMedium,
          ),
          const SizedBox(height: 12),
          SingleChildScrollView(
            scrollDirection: Axis.horizontal,
            child: Row(
              children: ValuePile.values.map((p) {
                return Padding(
                  padding: const EdgeInsets.only(right: 8),
                  child: ActionChip(
                    avatar: CircleAvatar(
                      backgroundColor: p.accent.withValues(alpha: 0.2),
                      radius: 8,
                    ),
                    label: Text('${p.shortLabel} ${sort.countInPile(p)}'),
                    onPressed: () => sort.openPileReview(p),
                    backgroundColor: p == pile
                        ? AppTheme.surfaceContainerHigh
                        : AppTheme.surfaceContainerLow,
                  ),
                );
              }).toList(),
            ),
          ),
          const SizedBox(height: 16),
          if (cards.isEmpty)
            Padding(
              padding: const EdgeInsets.symmetric(vertical: 40),
              child: Text(
                'No cards in this pile yet.',
                style: text.bodyLarge?.copyWith(color: colors.onSurfaceVariant),
                textAlign: TextAlign.center,
              ),
            )
          else
            ...cards.map((card) {
              return Padding(
                padding: const EdgeInsets.only(bottom: 12),
                child: ValueCardTile(
                  card: card,
                  compact: true,
                  trailing: Row(
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      IconButton(
                        tooltip: 'Promote',
                        onPressed: () => _shift(sort, card.id, pile, up: true),
                        icon: const Icon(Icons.arrow_upward),
                      ),
                      IconButton(
                        tooltip: 'Demote',
                        onPressed: () =>
                            _shift(sort, card.id, pile, up: false),
                        icon: const Icon(Icons.arrow_downward),
                      ),
                    ],
                  ),
                ),
              );
            }),
        ],
      ),
    );
  }

  void _shift(
    ValuesSortController sort,
    String id,
    ValuePile current, {
    required bool up,
  }) {
    final values = ValuePile.values;
    final index = values.indexOf(current);
    final next = up ? index - 1 : index + 1;
    if (next < 0 || next >= values.length) return;
    sort.moveCard(id, values[next]);
  }
}