import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import 'package:intl/intl.dart';
import '../../config/app_config.dart';
import '../../models/document_model.dart';
import '../../main.dart';
import 'pending_documents_provider.dart';
import '../editor/pdf_service.dart';
import '../../core/network/api_client.dart';
import 'pending_document_card.dart';
import 'document_card.dart';

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

  @override
  ConsumerState<DocumentsScreen> createState() => _DocumentsScreenState();
}

class _DocumentsScreenState extends ConsumerState<DocumentsScreen> {
  final _searchController = TextEditingController();
  List<DocumentModel> _allDocuments = [];
  List<DocumentModel> _filteredDocuments = [];
  String _selectedTab = 'DO'; // 'DO' | 'Product'

  @override
  void initState() {
    super.initState();
    _loadDocuments();
    _searchController.addListener(_onSearchChanged);
  }

  Future<void> _loadDocuments() async {
    final localStorage = ref.read(localStorageProvider);
    var docs = localStorage.getAllDocuments();
    final prefs = await SharedPreferences.getInstance();
    final currentStoreName = prefs.getString('nama_toko') ?? 'PM KELAPA DUA KARAWACI';

    bool databaseUpdated = false;

    final hasProductScan = docs.any((doc) => doc.orderUntuk == 'PRODUCT SCAN' && doc.kepadaYth == currentStoreName);
    if (!hasProductScan) {
      final mockProdDoc = DocumentModel(
        id: 'MOCK-PROD-SCAN-1',
        tanggal: DateFormat('dd MMMM yyyy').format(DateTime.now().subtract(const Duration(days: 1))),
        noPo: 'PO-PROD-12010119',
        noSo: '1002003004',
        noDo: 'Batch 1',
        kepadaYth: currentStoreName,
        orderUntuk: 'PRODUCT SCAN',
        alamat: 'Product Scan: Expired 15/12/2026',
        platTruk: 'B 1234 PFM',
        namaDriver: 'PRODUCT SCAN',
        namaPenerima: 'STORE STAFF',
        items: [
          DocumentItem(
            nomorSku: '12010119',
            namaBarang: 'FIESTA SPICY CHICKEN NUGGET 500 GR',
            banyak: '1',
            jumlah: '1',
          )
        ],
        createdAt: DateTime.now().subtract(const Duration(days: 1)),
      );
      await localStorage.saveDocument(mockProdDoc);
      databaseUpdated = true;
    }

    final hasDoScan = docs.any((doc) => doc.orderUntuk != 'PRODUCT SCAN' && doc.kepadaYth == currentStoreName);
    if (!hasDoScan) {
      final mockDoDoc = DocumentModel(
        id: 'MOCK-DO-SCAN-1',
        tanggal: DateFormat('dd MMMM yyyy').format(DateTime.now().subtract(const Duration(days: 2))),
        noPo: 'PO-9923488',
        noSo: '1002008892',
        noDo: 'DO-9988223',
        kepadaYth: currentStoreName,
        orderUntuk: 'DELIVERY ORDER',
        alamat: 'Jl. Boulevard Raya No. 12, Karawaci',
        platTruk: 'B 9876 PFM',
        namaDriver: 'Budi Santoso',
        namaPenerima: 'Staff Toko',
        items: [
          DocumentItem(
            nomorSku: '12010119',
            namaBarang: 'FIESTA SPICY CHICKEN NUGGET 500 GR',
            banyak: '10',
            jumlah: '10',
          )
        ],
        createdAt: DateTime.now().subtract(const Duration(days: 2)),
      );
      await localStorage.saveDocument(mockDoDoc);
      databaseUpdated = true;
    }

    if (databaseUpdated) {
      docs = localStorage.getAllDocuments();
    }

    setState(() {
      _allDocuments = docs;
      _filteredDocuments = docs;
    });

    try {
      final apiClient = ref.read(apiClientProvider);
      final response = await apiClient.client.get(AppConfig.fetchDocumentsEndpoint);
      final List serverData = response.data['data'] ?? [];
      final List<DocumentModel> serverDocs = serverData
          .map((json) => DocumentModel.fromJson(Map<String, dynamic>.from(json)))
          .toList();

      for (var doc in serverDocs) {
        await localStorage.saveDocument(doc);
      }

      final updatedDocs = localStorage.getAllDocuments();
      if (mounted) {
        setState(() {
          _allDocuments = updatedDocs;
          _filteredDocuments = updatedDocs;
        });
      }
    } catch (e) {
      debugPrint('Offline or failed fetching: $e');
    }
  }

  void _onSearchChanged() {
    final query = _searchController.text.toLowerCase();
    setState(() {
      _filteredDocuments = _allDocuments.where((doc) {
        return doc.noDo.toLowerCase().contains(query) ||
               doc.noPo.toString().contains(query) ||
               doc.noSo.toString().contains(query) ||
               doc.tanggal.toLowerCase().contains(query) ||
               doc.kepadaYth.toLowerCase().contains(query);
      }).toList();
    });
  }

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

  Future<void> _printReceipt(DocumentModel doc) async {
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('Membuat PDF...'), duration: Duration(seconds: 1), backgroundColor: AppConfig.secondaryColor),
    );
    await PdfService.generateAndPrintReceipt(doc);
  }

  @override
  Widget build(BuildContext context) {
    final pendingDocs = ref.watch(pendingDocumentsProvider);

    final tabFilteredDocs = _filteredDocuments.where((doc) {
      final isProduct = doc.orderUntuk == 'PRODUCT SCAN';
      if (_selectedTab == 'DO') return !isProduct;
      if (_selectedTab == 'Product') return isProduct;
      return true;
    }).toList();

    final Map<String, List<DocumentModel>> groupedDocs = {};
    for (var doc in tabFilteredDocs) {
      final date = doc.createdAt;
      final monthYearStr = DateFormat('MMMM yyyy').format(date);
      if (!groupedDocs.containsKey(monthYearStr)) {
        groupedDocs[monthYearStr] = [];
      }
      groupedDocs[monthYearStr]!.add(doc);
    }

    final List<Widget> listItems = [];

    if (pendingDocs.isNotEmpty) {
      listItems.add(
        Padding(
          padding: const EdgeInsets.only(bottom: AppConfig.spaceSmall),
          child: Text('Tertunda & Diproses', style: AppConfig.h3),
        ),
      );
      listItems.addAll(pendingDocs.map((doc) => PendingDocumentCard(
        doc: doc,
        onReload: () { if (mounted) _loadDocuments(); },
      )));
      listItems.add(const SizedBox(height: AppConfig.spaceLarge));
      listItems.add(const Divider());
      listItems.add(const SizedBox(height: AppConfig.spaceLarge));
    }

    if (groupedDocs.isNotEmpty) {
      groupedDocs.forEach((monthYear, docs) {
        listItems.add(
          Padding(
            padding: const EdgeInsets.only(top: AppConfig.spaceLarge, bottom: AppConfig.spaceSmall),
            child: Text(
              monthYear,
              style: AppConfig.bodyMedium.copyWith(
                fontWeight: FontWeight.bold,
                color: AppConfig.textSecondary,
              ),
            ),
          ),
        );
        listItems.addAll(docs.map((doc) => DocumentCard(
          doc: doc,
          onPrint: _printReceipt,
        )));
      });
    }

    return Scaffold(
      appBar: AppBar(
        title: const Text('Dokumen'),
        leading: IconButton(icon: const Icon(Icons.arrow_back), onPressed: () => context.go('/camera')),
      ),
      body: Column(
        children: [
          Container(
            padding: AppConfig.paddingLarge,
            color: AppConfig.surfaceColor,
            child: TextField(
              controller: _searchController,
              decoration: const InputDecoration(
                hintText: 'Cari berdasarkan No PO, No SO, DO, Tanggal...',
                prefixIcon: Icon(Icons.search),
              ),
            ),
          ),
          _buildTabSwitcher(),
          Expanded(
            child: (pendingDocs.isEmpty && tabFilteredDocs.isEmpty)
              ? Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Icon(Icons.folder_open, size: 64, color: AppConfig.textSecondary.withOpacity(0.5)),
                      const SizedBox(height: AppConfig.spaceLarge),
                      Text('Tidak ada dokumen ditemukan', style: AppConfig.bodyLarge),
                    ],
                  ),
                )
              : ListView(
                  padding: const EdgeInsets.symmetric(horizontal: AppConfig.spaceLarge),
                  children: listItems,
                ),
          ),
        ],
      ),
    );
  }

  Widget _buildTabSwitcher() {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: AppConfig.spaceLarge, vertical: AppConfig.spaceSmall),
      padding: const EdgeInsets.all(4),
      decoration: BoxDecoration(color: Colors.grey.shade100, borderRadius: BorderRadius.circular(AppConfig.borderRadiusMedium)),
      child: Row(
        children: [
          _buildTabItem('DO', 'DO Scan'),
          _buildTabItem('Product', 'Product Scan'),
        ],
      ),
    );
  }

  Widget _buildTabItem(String value, String label) {
    final isActive = _selectedTab == value;
    return Expanded(
      child: GestureDetector(
        onTap: () => setState(() { _selectedTab = value; }),
        child: Container(
          padding: const EdgeInsets.symmetric(vertical: 8),
          decoration: BoxDecoration(
            color: isActive ? Colors.white : Colors.transparent,
            borderRadius: BorderRadius.circular(AppConfig.borderRadiusSmall),
            boxShadow: isActive ? [BoxShadow(color: Colors.black.withOpacity(0.05), blurRadius: 4, offset: const Offset(0, 2))] : null,
          ),
          child: Center(
            child: Text(
              label,
              style: TextStyle(
                fontWeight: isActive ? FontWeight.bold : FontWeight.normal,
                color: isActive ? AppConfig.primaryColor : AppConfig.textSecondary,
              ),
            ),
          ),
        ),
      ),
    );
  }
}