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

import 'database.dart';
import 'library_service.dart';
import 'permissions.dart';
import 'song_list.dart';

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

  @override
  Widget build(BuildContext context) {
    final db = context.read<MeloDb>();
    final lib = context.watch<LibraryService>();
    return Scaffold(
      appBar: AppBar(
        title: const Text('Bibliothek'),
        actions: [
          IconButton(
            tooltip: addMusicLabel,
            icon: const Icon(Icons.create_new_folder_outlined),
            onPressed: lib.scanning ? null : lib.pickFolderAndScan,
          ),
          IconButton(
            tooltip: 'Erneut scannen',
            icon: const Icon(Icons.refresh),
            onPressed: lib.scanning ? null : lib.rescan,
          ),
        ],
      ),
      body: Column(
        children: [
          if (lib.permissionDenied)
            MaterialBanner(
              backgroundColor: Colors.red.shade900,
              content: const Text('Zugriff auf Musik verweigert. '
                  'Bitte in den Einstellungen erlauben.'),
              actions: [
                TextButton(
                  onPressed: openMusicPermissionSettings,
                  child: const Text('Einstellungen'),
                ),
              ],
            ),
          if (lib.scanning)
            Padding(
              padding: const EdgeInsets.all(12),
              child: Column(
                children: [
                  const LinearProgressIndicator(),
                  const SizedBox(height: 6),
                  Text(
                    'Scanne … ${lib.scanDone}'
                    '${lib.scanTotal > 0 ? ' / ${lib.scanTotal}' : ''}',
                    style: const TextStyle(color: Colors.white54, fontSize: 12),
                  ),
                ],
              ),
            ),
          Expanded(
            child: StreamBuilder<List<Song>>(
              stream: db.watchSongs(),
              builder: (context, snapshot) {
                final songs = snapshot.data ?? const [];
                if (songs.isEmpty && !lib.scanning) {
                  return const _Empty();
                }
                return SongList(songs);
              },
            ),
          ),
        ],
      ),
    );
  }
}

class _Empty extends StatelessWidget {
  const _Empty();

  @override
  Widget build(BuildContext context) {
    final lib = context.read<LibraryService>();
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Icon(Icons.library_music, size: 64, color: Colors.white24),
          const SizedBox(height: 12),
          const Text('Noch keine Musik',
              style: TextStyle(color: Colors.white54)),
          const SizedBox(height: 16),
          FilledButton.icon(
            icon: const Icon(Icons.create_new_folder_outlined),
            label: Text(addMusicLabel),
            onPressed: lib.pickFolderAndScan,
          ),
        ],
      ),
    );
  }
}