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

import 'package:timetrack/features/projects/domain/project.dart';
import 'package:timetrack/features/projects/domain/projects_provider.dart';
import 'package:timetrack/features/projects/presentation/widgets/project_form_sheet.dart';
import 'package:timetrack/features/projects/presentation/widgets/project_list_tile.dart';

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

  @override
  ConsumerState<ProjectsScreen> createState() => _ProjectsScreenState();
}

class _ProjectsScreenState extends ConsumerState<ProjectsScreen>
    with SingleTickerProviderStateMixin {
  late TabController _tabController;

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 2, vsync: this);
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Projects'),
        actions: [
          IconButton(
            icon: const Icon(Icons.add),
            tooltip: 'New project',
            onPressed: () => ProjectFormSheet.show(context),
          ),
        ],
        bottom: TabBar(
          controller: _tabController,
          tabs: const [
            Tab(text: 'Active'),
            Tab(text: 'Archived'),
          ],
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: const [
          _ProjectList(archived: false),
          _ProjectList(archived: true),
        ],
      ),
    );
  }
}

class _ProjectList extends ConsumerWidget {
  const _ProjectList({required this.archived});

  final bool archived;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final projectsAsync = archived
        ? ref.watch(allProjectsProvider)
        : ref.watch(activeProjectsProvider);

    return projectsAsync.when(
      data: (allProjects) {
        final projects = archived
            ? allProjects.where((p) => p.archivedAt != null).toList()
            : allProjects;

        if (projects.isEmpty) {
          return Center(
            key: Key(archived ? 'archived_empty' : 'active_empty'),
            child: Text(
              archived ? 'No archived projects.' : 'No projects yet.',
            ),
          );
        }

        return ListView.builder(
          itemCount: projects.length,
          itemBuilder: (context, index) {
            final project = projects[index];
            return ProjectListTile(
              key: Key('project_tile_${project.id}'),
              project: project,
              totalDuration: Duration.zero, // TODO: wire up from reports repo
              onTap: () => ProjectFormSheet.show(context, existing: project),
              onArchive: () => _toggleArchive(context, ref, project),
              onDelete: () => _confirmDelete(context, ref, project),
            );
          },
        );
      },
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (e, _) => Center(child: Text('Error: $e')),
    );
  }

  void _toggleArchive(BuildContext context, WidgetRef ref, Project project) {
    final notifier = ref.read(projectsNotifierProvider.notifier);
    if (project.archivedAt == null) {
      notifier.archive(project.id);
    } else {
      notifier.unarchive(project.id);
    }
  }

  Future<void> _confirmDelete(
    BuildContext context,
    WidgetRef ref,
    Project project,
  ) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Delete project?'),
        content: Text(
          'Delete "${project.name}"? This cannot be undone.\n\n'
          'Projects with existing entries cannot be deleted.',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx, false),
            child: const Text('Cancel'),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(ctx, true),
            style: FilledButton.styleFrom(
              backgroundColor: Theme.of(ctx).colorScheme.error,
            ),
            child: const Text('Delete'),
          ),
        ],
      ),
    );
    if (confirmed == true) {
      try {
        await ref.read(projectsNotifierProvider.notifier).delete(project.id);
      } catch (e) {
        if (context.mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('Cannot delete — project has time entries.'),
            ),
          );
        }
      }
    }
  }
}