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

import '../data/bible.dart';
import '../models/tracker.dart';
import '../services/progress.dart';
import '../services/tracker_service.dart';
import '../widgets/progress_bar.dart';
import '../widgets/theme.dart';

class StatsScreen extends ConsumerWidget {
  const StatsScreen({super.key, required this.trackerId});

  final String trackerId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final Tracker? tracker = ref.watch(trackerByIdProvider(trackerId));
    if (tracker == null) {
      return Scaffold(
        appBar: AppBar(),
        body: const Center(child: Text('Tracker not found')),
      );
    }
    final Color accent = Color(tracker.colorValue);
    final TrackerProgress progress = TrackerProgress(tracker);
    final int days = DateTime.now().difference(tracker.startDate).inDays;

    return Scaffold(
      appBar: AppBar(title: const Text('Stats')),
      body: ListView(
        padding: const EdgeInsets.all(AppTokens.spaceL),
        children: <Widget>[
          _OverallCard(tracker: tracker, accent: accent, progress: progress),
          const SizedBox(height: AppTokens.spaceL),
          _SectionCard(
            title: 'Old Testament',
            chapters: progress.chaptersReadInTestament(Testament.old),
            chaptersTotal: Bible.totalChaptersIn(Testament.old),
            books: progress.booksCompleted(Testament.old),
            booksTotal: Bible.totalBooksIn(Testament.old),
            fraction: progress.testamentFraction(Testament.old),
            accent: accent,
          ),
          const SizedBox(height: AppTokens.spaceL),
          _SectionCard(
            title: 'New Testament',
            chapters: progress.chaptersReadInTestament(Testament.newT),
            chaptersTotal: Bible.totalChaptersIn(Testament.newT),
            books: progress.booksCompleted(Testament.newT),
            booksTotal: Bible.totalBooksIn(Testament.newT),
            fraction: progress.testamentFraction(Testament.newT),
            accent: accent,
          ),
          const SizedBox(height: AppTokens.spaceL),
          Card(
            child: Padding(
              padding: const EdgeInsets.all(AppTokens.spaceL),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: <Widget>[
                  Text(
                    'Since you started',
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                  const SizedBox(height: AppTokens.spaceM),
                  _StatRow(
                    label: 'Start date',
                    value: _formatDate(tracker.startDate),
                  ),
                  _StatRow(label: 'Days reading', value: '$days'),
                  _StatRow(
                    label: 'Chapters read',
                    value: '${progress.totalRead} / ${Bible.totalChapters}',
                  ),
                  _StatRow(
                    label: 'Books completed',
                    value: '${progress.booksCompleted()} / ${Bible.totalBooks}',
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  static String _formatDate(DateTime date) {
    const List<String> months = <String>[
      'January',
      'February',
      'March',
      'April',
      'May',
      'June',
      'July',
      'August',
      'September',
      'October',
      'November',
      'December',
    ];
    return '${months[date.month - 1]} ${date.day}, ${date.year}';
  }
}

class _OverallCard extends StatelessWidget {
  const _OverallCard({
    required this.tracker,
    required this.accent,
    required this.progress,
  });

  final Tracker tracker;
  final Color accent;
  final TrackerProgress progress;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(AppTokens.spaceL),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            Text(tracker.name, style: Theme.of(context).textTheme.titleMedium),
            const SizedBox(height: AppTokens.spaceS),
            Text(
              '${(progress.overall * 100).toStringAsFixed(1)}%',
              style: Theme.of(context).textTheme.displaySmall?.copyWith(
                color: accent,
                fontWeight: FontWeight.w700,
              ),
            ),
            const SizedBox(height: AppTokens.spaceM),
            ProgressBar(value: progress.overall, color: accent, height: 10),
          ],
        ),
      ),
    );
  }
}

class _SectionCard extends StatelessWidget {
  const _SectionCard({
    required this.title,
    required this.chapters,
    required this.chaptersTotal,
    required this.books,
    required this.booksTotal,
    required this.fraction,
    required this.accent,
  });

  final String title;
  final int chapters;
  final int chaptersTotal;
  final int books;
  final int booksTotal;
  final double fraction;
  final Color accent;

  @override
  Widget build(BuildContext context) {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(AppTokens.spaceL),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: <Widget>[
                Text(title, style: Theme.of(context).textTheme.titleMedium),
                ProgressPill(fraction: fraction, color: accent),
              ],
            ),
            const SizedBox(height: AppTokens.spaceM),
            ProgressBar(value: fraction, color: accent),
            const SizedBox(height: AppTokens.spaceM),
            _StatRow(label: 'Chapters', value: '$chapters / $chaptersTotal'),
            _StatRow(label: 'Books', value: '$books / $booksTotal'),
          ],
        ),
      ),
    );
  }
}

class _StatRow extends StatelessWidget {
  const _StatRow({required this.label, required this.value});

  final String label;
  final String value;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: AppTokens.spaceXS),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: <Widget>[
          Text(
            label,
            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
              color: Theme.of(context).colorScheme.onSurfaceVariant,
            ),
          ),
          Text(
            value,
            style: Theme.of(
              context,
            ).textTheme.bodyMedium?.copyWith(fontWeight: FontWeight.w600),
          ),
        ],
      ),
    );
  }
}