import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:trainhub_flutter/core/theme/app_colors.dart';
import 'package:trainhub_flutter/core/constants/ui_constants.dart';
import 'package:trainhub_flutter/presentation/calendar/calendar_controller.dart';
import 'package:trainhub_flutter/presentation/calendar/widgets/program_selector.dart';
import 'package:trainhub_flutter/presentation/calendar/widgets/program_week_view.dart';
import 'package:trainhub_flutter/presentation/common/widgets/app_empty_state.dart';
import 'package:trainhub_flutter/presentation/common/dialogs/text_input_dialog.dart';
import 'package:trainhub_flutter/presentation/common/dialogs/confirm_dialog.dart';

@RoutePage()
class CalendarPage extends ConsumerWidget {
  const CalendarPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final state = ref.watch(calendarControllerProvider);
    final controller = ref.read(calendarControllerProvider.notifier);

    return state.when(
      data: (data) {
        if (data.programs.isEmpty) {
          return AppEmptyState(
            icon: Icons.calendar_month_outlined,
            title: 'No programs yet',
            subtitle: 'Create your first training program to start scheduling workouts',
            actionLabel: 'Create Program',
            onAction: () => _showCreateProgramDialog(context, controller),
          );
        }

        return Column(
          children: [
            ProgramSelector(
              programs: data.programs,
              activeProgram: data.activeProgram,
              onProgramSelected: (p) => controller.loadProgram(p.id),
              onCreateProgram: () =>
                  _showCreateProgramDialog(context, controller),
              onDuplicateProgram: () {
                if (data.activeProgram != null) {
                  controller.duplicateProgram(data.activeProgram!.id);
                }
              },
              onDeleteProgram: () async {
                if (data.activeProgram != null) {
                  final confirmed = await ConfirmDialog.show(
                    context,
                    title: 'Delete Program?',
                    message:
                        'Are you sure you want to delete "${data.activeProgram!.name}"? This cannot be undone.',
                  );
                  if (confirmed == true) {
                    controller.deleteProgram(data.activeProgram!.id);
                  }
                }
              },
            ),
            Expanded(
              child: data.activeProgram == null
                  ? const Center(
                      child: Text(
                        'Select a program to view its schedule',
                        style: TextStyle(
                          color: AppColors.textMuted,
                          fontSize: 14,
                        ),
                      ),
                    )
                  : ListView.builder(
                      padding: const EdgeInsets.all(UIConstants.spacing24),
                      itemCount: data.weeks.length + 1,
                      itemBuilder: (context, index) {
                        if (index == data.weeks.length) {
                          return Padding(
                            padding: const EdgeInsets.symmetric(vertical: UIConstants.spacing24),
                            child: Center(
                              child: OutlinedButton.icon(
                                onPressed: controller.addWeek,
                                icon: const Icon(Icons.add, size: 18),
                                label: const Text('Add Week'),
                              ),
                            ),
                          );
                        }
                        final week = data.weeks[index];
                        final weekWorkouts = data.workouts
                            .where((w) => w.weekId == week.id)
                            .toList();
                        return ProgramWeekView(
                          week: week,
                          workouts: weekWorkouts,
                          availablePlans: data.plans,
                          onAddWorkout: (workout) =>
                              controller.addWorkout(workout),
                          onDeleteWorkout: controller.deleteWorkout,
                        );
                      },
                    ),
            ),
          ],
        );
      },
      error: (e, s) => Center(
        child: Text(
          'Error: $e',
          style: const TextStyle(color: AppColors.destructive),
        ),
      ),
      loading: () => const Center(child: CircularProgressIndicator()),
    );
  }

  Future<void> _showCreateProgramDialog(
    BuildContext context,
    CalendarController controller,
  ) async {
    final name = await TextInputDialog.show(
      context,
      title: 'New Program',
      hintText: 'e.g. 12 Week Strength',
    );
    if (name != null && name.isNotEmpty) {
      controller.createProgram(name);
    }
  }
}