import 'package:e_receipt_mobile/domain/entities/login_user.dart';
import 'package:e_receipt_mobile/presentation/auth/logout_view_model.dart';
import 'package:e_receipt_mobile/presentation/home/home_pagination_providers.dart';
import 'package:e_receipt_mobile/presentation/home/merchant_paging_view_model.dart';
import 'package:e_receipt_mobile/presentation/home/widgets/home_drawer.dart';
import 'package:e_receipt_mobile/presentation/home/widgets/merchant_header.dart';
import 'package:e_receipt_mobile/presentation/home/widgets/merchant_list_view.dart';
import 'package:e_receipt_mobile/presentation/terminal/terminal_selection_screen.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

class HomeScreen extends ConsumerWidget {
  const HomeScreen({required this.user, super.key});

  final LoginUser user;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final pagingState = ref.watch(merchantPagingViewModelProvider);
    final pagingViewModel = ref.read(merchantPagingViewModelProvider.notifier);
    final logoutState = ref.watch(logoutViewModelProvider);
    final colorScheme = Theme.of(context).colorScheme;
    final query = ref.watch(merchantSearchQueryProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('Merchants'),
        actions: [
          IconButton(
            tooltip: 'Refresh',
            onPressed: pagingState.isLoading
                ? null
                : () => pagingViewModel.refresh(),
            icon: const Icon(Icons.refresh),
          ),
        ],
      ),
      drawer: HomeDrawer(
        user: user,
        onLogout: () async {
          if (logoutState.isLoading) {
            return;
          }
          final shouldLogout = await showDialog<bool>(
            context: context,
            builder: (context) {
              return AlertDialog(
                title: const Text('Logout'),
                content: const Text('Are you sure you want to logout?'),
                actions: [
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(false),
                    child: const Text('Cancel'),
                  ),
                  TextButton(
                    onPressed: () => Navigator.of(context).pop(true),
                    child: const Text('Logout'),
                  ),
                ],
              );
            },
          );

          if (shouldLogout != true || !context.mounted) {
            return;
          }

          Navigator.of(context).pop(); // close drawer
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('Signed out'),
              behavior: SnackBarBehavior.floating,
            ),
          );
          await ref.read(logoutViewModelProvider.notifier).logout();
        },
      ),
      body: pagingState.isLoading && pagingState.items.isEmpty
          ? const Center(child: CircularProgressIndicator())
          : pagingState.errorMessage != null && pagingState.items.isEmpty
          ? Center(
              child: Padding(
                padding: EdgeInsets.fromLTRB(
                  24,
                  24,
                  24,
                  MediaQuery.viewPaddingOf(context).bottom + 24,
                ),
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Icon(
                      Icons.wifi_off_outlined,
                      size: 56,
                      color: colorScheme.onSurfaceVariant,
                    ),
                    const SizedBox(height: 12),
                    Text(
                      'Failed to load merchants',
                      style: Theme.of(context).textTheme.titleMedium,
                      textAlign: TextAlign.center,
                    ),
                    const SizedBox(height: 6),
                    Text(
                      pagingState.errorMessage!,
                      style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                        color: colorScheme.onSurfaceVariant,
                      ),
                      textAlign: TextAlign.center,
                    ),
                    const SizedBox(height: 14),
                    FilledButton.tonal(
                      onPressed: pagingViewModel.refresh,
                      child: const Text('Try again'),
                    ),
                  ],
                ),
              ),
            )
          : Column(
              crossAxisAlignment: CrossAxisAlignment.stretch,
              children: [
                MerchantHeader(
                  loadedCount: pagingState.items.length,
                  query: query,
                  onQueryChanged: (value) {
                    ref.read(merchantSearchQueryProvider.notifier).state =
                        value;
                    pagingViewModel.setSearchTerm(value);
                  },
                  onClear: () {
                    ref.read(merchantSearchQueryProvider.notifier).state = '';
                    pagingViewModel.setSearchTerm('');
                  },
                ),
                Expanded(
                  child: MerchantListView(
                    merchants: pagingState.items,
                    hasMore: pagingState.hasMore,
                    isLoadingMore: pagingState.isLoadingMore,
                    onRefresh: pagingViewModel.refresh,
                    onMerchantTap: (merchant) {
                      final id = merchant.id;
                      if (id == null) {
                        return;
                      }
                      _openTerminalSelection(context, id, merchant.name ?? '-');
                    },
                    onLoadMore: pagingViewModel.loadMore,
                    onEndReached: pagingViewModel.loadMore,
                  ),
                ),
                if (pagingState.errorMessage != null &&
                    pagingState.items.isNotEmpty)
                  Padding(
                    padding: EdgeInsets.fromLTRB(
                      16,
                      8,
                      16,
                      MediaQuery.viewPaddingOf(context).bottom + 8,
                    ),
                    child: Material(
                      color: colorScheme.errorContainer,
                      borderRadius: BorderRadius.circular(16),
                      child: Padding(
                        padding: const EdgeInsets.all(12),
                        child: Row(
                          children: [
                            Icon(
                              Icons.error_outline,
                              color: colorScheme.onErrorContainer,
                            ),
                            const SizedBox(width: 10),
                            Expanded(
                              child: Text(
                                pagingState.errorMessage!,
                                style: Theme.of(context).textTheme.bodyMedium
                                    ?.copyWith(
                                      color: colorScheme.onErrorContainer,
                                    ),
                              ),
                            ),
                            const SizedBox(width: 8),
                            TextButton(
                              onPressed: pagingViewModel.loadMore,
                              child: const Text('Retry'),
                            ),
                          ],
                        ),
                      ),
                    ),
                  ),
              ],
            ),
    );
  }



  void _openTerminalSelection(
    BuildContext context,
    String merchantId,
    String merchantName,
  ) {
    Navigator.of(context).push(
      MaterialPageRoute<void>(
        builder: (_) => TerminalSelectionScreen(
          merchantId: merchantId,
          merchantName: merchantName,
        ),
      ),
    );
  }
}