/// Promotions Page
///
/// Displays all available promotions with a featured promotion card
/// at the top and a scrollable list of promotion cards below.
library;

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:font_awesome_flutter/font_awesome_flutter.dart';
import 'package:go_router/go_router.dart';
import 'package:worker/core/theme/colors.dart';
import 'package:worker/features/home/domain/entities/promotion.dart';
import 'package:worker/features/home/presentation/providers/promotions_provider.dart';
import 'package:worker/features/promotions/presentation/widgets/featured_promotion_card.dart';
import 'package:worker/features/promotions/presentation/widgets/promotion_card.dart';

/// Promotions Page
///
/// Shows:
/// - Header bar with title
/// - Featured promotion card (gradient background)
/// - List of promotion cards
///
/// Layout designed for 375px width mobile screens.
class PromotionsPage extends ConsumerWidget {
  const PromotionsPage({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    // Watch promotions provider (same as home page)
    final promotionsAsync = ref.watch(promotionsProvider);

    return Scaffold(
      backgroundColor: const Color(0xFFF4F6F8),
      body: SafeArea(
        child: Column(
          children: [
            // Header
            _buildHeader(),

            // Scrollable content
            Expanded(
              child: promotionsAsync.when(
                data: (promotions) =>
                    _buildPromotionsContent(context, promotions),
                loading: () => const Center(child: CircularProgressIndicator()),
                error: (error, stack) => Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      const FaIcon(
                        FontAwesomeIcons.circleExclamation,
                        color: AppColors.danger,
                        size: 48,
                      ),
                      const SizedBox(height: 16),
                      Text(
                        'Không thể tải khuyến mãi',
                        style: const TextStyle(
                          fontSize: 16,
                          fontWeight: FontWeight.w600,
                          color: AppColors.grey900,
                        ),
                      ),
                      const SizedBox(height: 8),
                      Text(
                        error.toString(),
                        style: const TextStyle(
                          fontSize: 14,
                          color: AppColors.grey500,
                        ),
                        textAlign: TextAlign.center,
                      ),
                    ],
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  /// Build header bar
  Widget _buildHeader() {
    return Container(
      width: double.infinity,
      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 16),
      decoration: BoxDecoration(
        color: Colors.white,
        boxShadow: [
          BoxShadow(
            color: Colors.black.withValues(alpha: 0.05),
            blurRadius: 8,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: const Text(
        'Khuyến mãi',
        style: TextStyle(
          fontSize: 18,
          fontWeight: FontWeight.bold,
          color: Color(0xFF212121),
        ),
      ),
    );
  }

  /// Build promotions content with featured card and list
  Widget _buildPromotionsContent(
    BuildContext context,
    List<Promotion> promotions,
  ) {
    if (promotions.isEmpty) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            FaIcon(
              FontAwesomeIcons.tag,
              size: 64,
              color: AppColors.grey500,
            ),
            const SizedBox(height: 16),
            Text(
              'Chưa có khuyến mãi',
              style: const TextStyle(
                fontSize: 16,
                fontWeight: FontWeight.w600,
                color: AppColors.grey900,
              ),
            ),
            const SizedBox(height: 8),
            Text(
              'Hãy quay lại sau để xem các ưu đãi mới',
              style: const TextStyle(fontSize: 14, color: AppColors.grey500),
            ),
          ],
        ),
      );
    }

    return CustomScrollView(
      slivers: [
        // Featured Promotion Card (first promotion)
        SliverToBoxAdapter(
          child: Padding(
            padding: const EdgeInsets.only(top: 16, bottom: 24),
            child: FeaturedPromotionCard(
              title: promotions.first.title,
              subtitle: promotions.first.description,
              timerText: 'Còn 2 ngày 15:30:45',
              onTap: () {
                context.push('/promotions/${promotions.first.id}');
              },
            ),
          ),
        ),

        // Promotion List (all promotions)
        SliverPadding(
          padding: const EdgeInsets.symmetric(horizontal: 16),
          sliver: SliverList(
            delegate: SliverChildListDelegate(
              promotions
                  .map(
                    (promotion) => PromotionCard(
                      promotion: promotion,
                      onTap: () {
                        context.push('/promotions/${promotion.id}');
                      },
                    ),
                  )
                  .toList(),
            ),
          ),
        ),

        // Bottom padding for navigation clearance
        const SliverToBoxAdapter(child: SizedBox(height: 16)),
      ],
    );
  }
}