import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:google_fonts/google_fonts.dart';
import 'package:trainhub_flutter/core/constants/ui_constants.dart';
import 'package:trainhub_flutter/core/theme/app_colors.dart';
import 'package:trainhub_flutter/presentation/common/widgets/app_empty_state.dart';
import 'package:trainhub_flutter/presentation/home/home_controller.dart';
import 'package:trainhub_flutter/presentation/home/home_state.dart';
import 'package:trainhub_flutter/presentation/home/widgets/next_workout_banner.dart';
import 'package:trainhub_flutter/presentation/home/widgets/quick_actions_row.dart';
import 'package:trainhub_flutter/presentation/home/widgets/recent_activity_section.dart';
import 'package:trainhub_flutter/presentation/home/widgets/stat_cards_row.dart';
import 'package:trainhub_flutter/presentation/home/widgets/welcome_header.dart';

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

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final asyncState = ref.watch(homeControllerProvider);

    return asyncState.when(
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (e, _) => _ErrorView(
        error: e,
        onRetry: () => ref.read(homeControllerProvider.notifier).refresh(),
      ),
      data: (data) {
        if (data.activeProgramName == null) {
          return AppEmptyState(
            icon: Icons.calendar_today_outlined,
            title: 'No active program',
            subtitle:
                'Head to Calendar to create or select a training program to get started.',
            actionLabel: 'Go to Calendar',
            onAction: () => AutoTabsRouter.of(context).setActiveIndex(3),
          );
        }
        return _HomeContent(data: data);
      },
    );
  }
}

class _ErrorView extends StatelessWidget {
  const _ErrorView({required this.error, required this.onRetry});

  final Object error;
  final VoidCallback onRetry;

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(UIConstants.pagePadding),
        child: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Icon(
              Icons.error_outline,
              size: 48,
              color: AppColors.destructive,
            ),
            const SizedBox(height: UIConstants.spacing16),
            Text(
              'Something went wrong',
              style: GoogleFonts.inter(
                fontSize: 16,
                fontWeight: FontWeight.w600,
                color: AppColors.textPrimary,
              ),
            ),
            const SizedBox(height: UIConstants.spacing8),
            Text(
              '$error',
              style: GoogleFonts.inter(
                fontSize: 13,
                color: AppColors.textMuted,
              ),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: UIConstants.spacing24),
            FilledButton.icon(
              onPressed: onRetry,
              icon: const Icon(Icons.refresh, size: 18),
              label: const Text('Retry'),
            ),
          ],
        ),
      ),
    );
  }
}

class _HomeContent extends StatelessWidget {
  const _HomeContent({required this.data});

  final HomeState data;

  @override
  Widget build(BuildContext context) {
    return SingleChildScrollView(
      padding: const EdgeInsets.all(UIConstants.pagePadding),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          WelcomeHeader(programName: data.activeProgramName!),
          const SizedBox(height: UIConstants.spacing24),
          StatCardsRow(
            completed: data.completedWorkouts,
            total: data.totalWorkouts,
          ),
          const SizedBox(height: UIConstants.spacing24),
          if (data.nextWorkoutName != null) ...[
            NextWorkoutBanner(workoutName: data.nextWorkoutName!),
            const SizedBox(height: UIConstants.spacing24),
          ],
          const QuickActionsRow(),
          const SizedBox(height: UIConstants.spacing32),
          RecentActivitySection(activity: data.recentActivity),
        ],
      ),
    );
  }
}