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

import '../../core/exceptions.dart';
import '../../providers/projects_provider.dart';

class ProjectEditScreen extends ConsumerStatefulWidget {
  final int? projectId;
  const ProjectEditScreen({super.key, this.projectId});

  @override
  ConsumerState<ProjectEditScreen> createState() => _ProjectEditScreenState();
}

class _ProjectEditScreenState extends ConsumerState<ProjectEditScreen> {
  final _titleController = TextEditingController();
  final _descController = TextEditingController();
  final _goalController = TextEditingController();
  String _status = 'active';
  bool _saving = false;
  late final Future<void> _initFuture;

  @override
  void initState() {
    super.initState();
    _initFuture =
        widget.projectId != null ? _loadExisting() : Future.value();
  }

  @override
  void dispose() {
    _titleController.dispose();
    _descController.dispose();
    _goalController.dispose();
    super.dispose();
  }

  Future<void> _loadExisting() async {
    final projects = ref.read(projectsProvider).value ?? [];
    final project =
        projects.where((p) => p.id == widget.projectId).firstOrNull;
    if (project != null) {
      _titleController.text = project.title;
      _descController.text = project.description ?? '';
      _goalController.text = project.goal ?? '';
      _status = project.status;
    }
  }

  Future<void> _save() async {
    final title = _titleController.text.trim();
    if (title.isEmpty) {
      ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(content: Text('Title is required.')));
      return;
    }
    setState(() => _saving = true);
    try {
      if (widget.projectId == null) {
        await ref.read(projectsProvider.notifier).create(
              title: title,
              description: _descController.text.trim().isEmpty
                  ? null
                  : _descController.text.trim(),
              goal: _goalController.text.trim().isEmpty
                  ? null
                  : _goalController.text.trim(),
            );
      } else {
        await ref.read(projectsProvider.notifier).updateProject(
              widget.projectId!,
              {
                'title': title,
                'description': _descController.text.trim(),
                'goal': _goalController.text.trim(),
                'status': _status,
              },
            );
      }
      if (mounted) context.pop();
    } on AppException catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context)
            .showSnackBar(SnackBar(content: Text(e.message)));
      }
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return FutureBuilder(
      future: _initFuture,
      builder: (context, snapshot) => Scaffold(
        appBar: AppBar(
          title: Text(
              widget.projectId == null ? 'New Project' : 'Edit Project'),
          actions: [
            IconButton(
              icon: _saving
                  ? const SizedBox(
                      width: 20,
                      height: 20,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    )
                  : const Icon(Icons.check),
              onPressed: _saving ? null : _save,
            ),
          ],
        ),
        body: snapshot.connectionState == ConnectionState.waiting
            ? const Center(child: CircularProgressIndicator())
            : ListView(
                padding: const EdgeInsets.all(16),
                children: [
                  TextField(
                    controller: _titleController,
                    decoration: const InputDecoration(
                        labelText: 'Title *', border: OutlineInputBorder()),
                    textInputAction: TextInputAction.next,
                  ),
                  const SizedBox(height: 12),
                  TextField(
                    controller: _descController,
                    decoration: const InputDecoration(
                        labelText: 'Description',
                        border: OutlineInputBorder()),
                    maxLines: 3,
                    textInputAction: TextInputAction.next,
                  ),
                  const SizedBox(height: 12),
                  TextField(
                    controller: _goalController,
                    decoration: const InputDecoration(
                        labelText: 'Goal', border: OutlineInputBorder()),
                    maxLines: 2,
                    textInputAction: TextInputAction.done,
                  ),
                  if (widget.projectId != null) ...[
                    const SizedBox(height: 12),
                    DropdownButtonFormField<String>(
                      initialValue: _status,
                      decoration: const InputDecoration(
                          labelText: 'Status',
                          border: OutlineInputBorder()),
                      items: const [
                        DropdownMenuItem(
                            value: 'active', child: Text('Active')),
                        DropdownMenuItem(
                            value: 'completed', child: Text('Completed')),
                        DropdownMenuItem(
                            value: 'archived', child: Text('Archived')),
                      ],
                      onChanged: (v) => setState(() => _status = v!),
                    ),
                  ],
                ],
              ),
      ),
    );
  }
}