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

import '../../core/constants.dart';
import '../../providers/notes_provider.dart';

class NotesListScreen extends ConsumerStatefulWidget {
  const NotesListScreen({super.key});

  @override
  ConsumerState<NotesListScreen> createState() => _NotesListScreenState();
}

class _NotesListScreenState extends ConsumerState<NotesListScreen> {
  bool _showSearch = false;
  String _search = '';

  @override
  Widget build(BuildContext context) {
    final notesAsync = ref.watch(notesProvider);

    return Scaffold(
      appBar: AppBar(
        automaticallyImplyLeading: false,
        title: _showSearch
            ? TextField(
                autofocus: true,
                decoration: const InputDecoration(
                  hintText: 'Search notes…',
                  border: InputBorder.none,
                ),
                onChanged: (v) =>
                    setState(() => _search = v.trim().toLowerCase()),
              )
            : null,
        actions: [
          if (_showSearch)
            IconButton(
              icon: const Icon(Icons.close),
              tooltip: 'Close search',
              onPressed: () => setState(() {
                _showSearch = false;
                _search = '';
              }),
            )
          else
            IconButton(
              icon: const Icon(Icons.search),
              tooltip: 'Search',
              onPressed: () => setState(() => _showSearch = true),
            ),
        ],
      ),
      body: notesAsync.when(
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (_, _) => Center(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              const Icon(Icons.cloud_off, size: 48),
              const SizedBox(height: 12),
              const Text('Could not load notes.'),
              const SizedBox(height: 4),
              TextButton(
                onPressed: () => ref.invalidate(notesProvider),
                child: const Text('Retry'),
              ),
            ],
          ),
        ),
        data: (notes) {
          final filtered = _search.isEmpty
              ? notes
              : notes
                  .where((n) =>
                      n.title.toLowerCase().contains(_search) ||
                      n.body.toLowerCase().contains(_search))
                  .toList();

          if (filtered.isEmpty) {
            return Center(
              child: Text(
                _search.isEmpty
                    ? 'No notes yet. Tap + to create one.'
                    : 'No notes match "$_search".',
              ),
            );
          }

          return RefreshIndicator(
            onRefresh: () => ref.refresh(notesProvider.future),
            child: ListView.separated(
              itemCount: filtered.length,
              separatorBuilder: (_, _) => const Divider(height: 1),
              itemBuilder: (context, i) {
                final note = filtered[i];
                final preview = note.body
                    .split('\n')
                    .firstWhere((l) => l.trim().isNotEmpty, orElse: () => '')
                    .trim();
                return ListTile(
                  title: Text(note.title),
                  subtitle: Text(
                    preview.isNotEmpty
                        ? preview
                        : note.updatedAt.toLocal().toString().substring(0, 16),
                    style: Theme.of(context).textTheme.bodySmall?.copyWith(
                          color: Theme.of(context).colorScheme.onSurfaceVariant,
                        ),
                    maxLines: 1,
                    overflow: TextOverflow.ellipsis,
                  ),
                  onTap: () => context.push(
                    Routes.noteDetail.replaceFirst(':id', '${note.id}'),
                  ),
                );
              },
            ),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        heroTag: 'notes_fab',
        onPressed: () => context.push(Routes.noteNew),
        child: const Icon(Icons.add),
      ),
    );
  }
}