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/book_tile.dart';
import '../widgets/progress_bar.dart';
import '../widgets/theme.dart';
import 'book_screen.dart';
import 'stats_screen.dart';

class TrackerScreen extends ConsumerWidget {
  const TrackerScreen({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);

    return Scaffold(
      appBar: AppBar(
        title: Text(tracker.name),
        actions: <Widget>[
          IconButton(
            tooltip: 'Stats',
            icon: const Icon(Icons.insert_chart_outlined),
            onPressed: () => Navigator.of(context).push<void>(
              MaterialPageRoute<void>(
                builder: (_) => StatsScreen(trackerId: tracker.id),
              ),
            ),
          ),
        ],
      ),
      body: CustomScrollView(
        slivers: <Widget>[
          SliverToBoxAdapter(
            child: _HeaderCard(
              tracker: tracker,
              accent: accent,
              progress: progress,
            ),
          ),
          SliverToBoxAdapter(
            child: _SectionHeader(
              title: 'Old Testament',
              chaptersRead: progress.chaptersReadInTestament(Testament.old),
              total: Bible.totalChaptersIn(Testament.old),
            ),
          ),
          _BooksSliver(
            tracker: tracker,
            accent: accent,
            testament: Testament.old,
          ),
          SliverToBoxAdapter(
            child: _SectionHeader(
              title: 'New Testament',
              chaptersRead: progress.chaptersReadInTestament(Testament.newT),
              total: Bible.totalChaptersIn(Testament.newT),
            ),
          ),
          _BooksSliver(
            tracker: tracker,
            accent: accent,
            testament: Testament.newT,
          ),
          const SliverToBoxAdapter(child: SizedBox(height: AppTokens.spaceXL)),
        ],
      ),
    );
  }
}

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

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

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(AppTokens.spaceL),
      child: Card(
        child: Padding(
          padding: const EdgeInsets.all(AppTokens.spaceL),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: <Widget>[
              Row(
                children: <Widget>[
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: <Widget>[
                        Text(
                          '${(progress.overall * 100).toStringAsFixed(1)}%',
                          style: Theme.of(context).textTheme.headlineMedium
                              ?.copyWith(
                                color: accent,
                                fontWeight: FontWeight.w700,
                              ),
                        ),
                        const SizedBox(height: AppTokens.spaceXS),
                        Text(
                          '${progress.totalRead} / ${Bible.totalChapters} chapters',
                          style: Theme.of(context).textTheme.bodyMedium
                              ?.copyWith(
                                color: Theme.of(
                                  context,
                                ).colorScheme.onSurfaceVariant,
                              ),
                        ),
                      ],
                    ),
                  ),
                  Column(
                    crossAxisAlignment: CrossAxisAlignment.end,
                    children: <Widget>[
                      Text(
                        'Started',
                        style: Theme.of(context).textTheme.labelSmall?.copyWith(
                          color: Theme.of(context).colorScheme.onSurfaceVariant,
                        ),
                      ),
                      const SizedBox(height: AppTokens.spaceXS),
                      Text(
                        _formatDate(tracker.startDate),
                        style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                          fontWeight: FontWeight.w500,
                        ),
                      ),
                    ],
                  ),
                ],
              ),
              const SizedBox(height: AppTokens.spaceL),
              ProgressBar(value: progress.overall, color: accent, height: 8),
            ],
          ),
        ),
      ),
    );
  }

  static String _formatDate(DateTime date) {
    const List<String> months = <String>[
      'Jan',
      'Feb',
      'Mar',
      'Apr',
      'May',
      'Jun',
      'Jul',
      'Aug',
      'Sep',
      'Oct',
      'Nov',
      'Dec',
    ];
    return '${months[date.month - 1]} ${date.day}, ${date.year}';
  }
}

class _SectionHeader extends StatelessWidget {
  const _SectionHeader({
    required this.title,
    required this.chaptersRead,
    required this.total,
  });

  final String title;
  final int chaptersRead;
  final int total;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.fromLTRB(
        AppTokens.spaceL,
        AppTokens.spaceL,
        AppTokens.spaceL,
        AppTokens.spaceS,
      ),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: <Widget>[
          Text(
            title,
            style: Theme.of(
              context,
            ).textTheme.titleMedium?.copyWith(fontWeight: FontWeight.w600),
          ),
          Text(
            '$chaptersRead / $total',
            style: Theme.of(context).textTheme.labelMedium?.copyWith(
              color: Theme.of(context).colorScheme.onSurfaceVariant,
            ),
          ),
        ],
      ),
    );
  }
}

class _BooksSliver extends ConsumerWidget {
  const _BooksSliver({
    required this.tracker,
    required this.accent,
    required this.testament,
  });

  final Tracker tracker;
  final Color accent;
  final Testament testament;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final List<Book> books = Bible.books
        .where((Book book) => book.testament == testament)
        .toList(growable: false);
    final TrackerProgress progress = TrackerProgress(tracker);
    return SliverList.separated(
      itemCount: books.length,
      separatorBuilder: (_, __) => const Divider(indent: AppTokens.spaceXL),
      itemBuilder: (BuildContext context, int index) {
        final Book book = books[index];
        return BookTile(
          book: book,
          chaptersRead: progress.chaptersReadIn(book),
          accent: accent,
          onTap: () => Navigator.of(context).push<void>(
            MaterialPageRoute<void>(
              builder: (_) =>
                  BookScreen(trackerId: tracker.id, bookIndex: book.index),
            ),
          ),
        );
      },
    );
  }
}