import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lucide_icons/lucide_icons.dart';
import '../../providers/business_provider.dart';

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

  @override
  ConsumerState<BusinessSettingsScreen> createState() => _BusinessSettingsScreenState();
}

class _BusinessSettingsScreenState extends ConsumerState<BusinessSettingsScreen> {
  bool _taxIncludedInPrice = false;
  bool _salesEnabled = true;
  bool _inventoryEnabled = true;

  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final profile = ref.read(businessProfileProvider).value;
      if (profile != null) {
        setState(() {
          _taxIncludedInPrice = profile.taxIncludedInPrice ?? false;
        });
      }
      final feature = ref.read(businessFeatureProvider).value;
      if (feature != null) {
        setState(() {
          _inventoryEnabled = feature.inventoryManagement;
          _salesEnabled = feature.salesManagement;
        });
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Business Settings'),
        elevation: 0,
        backgroundColor: Colors.transparent,
      ),
      body: ListView(
        padding: const EdgeInsets.all(24.0),
        children: [
          const Text('Module Configuration', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold, color: Colors.grey)),
          const SizedBox(height: 16),
          SwitchListTile(
            title: const Text('Inventory Management'),
            subtitle: const Text('Track stock levels, multiple locations, and products'),
            value: _inventoryEnabled,
            onChanged: (val) {
              setState(() => _inventoryEnabled = val);
              _saveFeatures();
            },
            secondary: const Icon(LucideIcons.package),
          ),
          SwitchListTile(
            title: const Text('Sales & POS'),
            subtitle: const Text('Enable point of sale, invoicing, and receivables'),
            value: _salesEnabled,
            onChanged: (val) {
              setState(() => _salesEnabled = val);
              _saveFeatures();
            },
            secondary: const Icon(LucideIcons.shoppingCart),
          ),
          const SizedBox(height: 32),
          const Text('Inventory Strategy', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold, color: Colors.grey)),
          const SizedBox(height: 16),
          Consumer(
            builder: (context, ref, child) {
              final featureState = ref.watch(businessFeatureProvider);
              final currentStrategy = featureState.value?.bomReductionStrategy ?? 'COMPONENTS_ONLY';
              final deductParentStock = currentStrategy == 'PARENT_AND_COMPONENTS';
              final stockDeductionOnInvoice = featureState.value?.stockDeductionOnInvoice ?? true;
              
              return Column(
                children: [
                  SwitchListTile(
                    title: const Text('Deduct Parent Stock on BOM Sale'),
                    subtitle: const Text('If enabled, selling an assembled product reduces both parent and component stock.'),
                    value: deductParentStock,
                    secondary: const Icon(LucideIcons.gitMerge),
                    onChanged: (val) {
                      if (featureState.value != null) {
                        final newStrategy = val ? 'PARENT_AND_COMPONENTS' : 'COMPONENTS_ONLY';
                        final updated = featureState.value!.copyWith(bomReductionStrategy: newStrategy);
                        ref.read(businessFeatureProvider.notifier).updateFeatures(updated);
                      }
                    },
                  ),
                  SwitchListTile(
                    title: const Text('Stock Deduction on Invoice'),
                    subtitle: const Text('If enabled, finalizing an invoice automatically deducts product stock. Turn off for a two-step fulfillment process.'),
                    value: stockDeductionOnInvoice,
                    secondary: const Icon(LucideIcons.boxes),
                    onChanged: (val) {
                      if (featureState.value != null) {
                        final updated = featureState.value!.copyWith(stockDeductionOnInvoice: val);
                        ref.read(businessFeatureProvider.notifier).updateFeatures(updated);
                      }
                    },
                  ),
                  SwitchListTile(
                    title: const Text('Use EAN/Barcode for Scanner'),
                    subtitle: const Text('If disabled, the barcode scanner will search using the SKU field instead.'),
                    value: (featureState.value?.barcodeSource ?? 'SKU') == 'BARCODE',
                    secondary: const Icon(LucideIcons.scanLine),
                    onChanged: (val) {
                      if (featureState.value != null) {
                        final updated = featureState.value!.copyWith(barcodeSource: val ? 'BARCODE' : 'SKU');
                        ref.read(businessFeatureProvider.notifier).updateFeatures(updated);
                      }
                    },
                  ),
                ],
              );
            }
          ),
          const SizedBox(height: 32),
          const Text('Pricing & Taxation', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold, color: Colors.grey)),
          const SizedBox(height: 16),
          SwitchListTile(
            title: const Text('Selling Price includes Tax'),
            subtitle: const Text('If enabled, GST is assumed to be inclusive in the entered selling price.'),
            value: _taxIncludedInPrice,
            onChanged: (val) {
              setState(() => _taxIncludedInPrice = val);
              _saveSettings();
            },
            secondary: const Icon(LucideIcons.receipt),
          ),
        ],
      ),
    );
  }

  void _saveSettings() {
    final profileState = ref.read(businessProfileProvider).value;
    if (profileState != null) {
      final updated = profileState.copyWith(taxIncludedInPrice: _taxIncludedInPrice);
      ref.read(businessProfileProvider.notifier).updateProfile(updated);
    }
  }

  void _saveFeatures() {
    final featureState = ref.read(businessFeatureProvider).value;
    if (featureState != null) {
      final updated = featureState.copyWith(
        inventoryManagement: _inventoryEnabled,
        salesManagement: _salesEnabled,
      );
      ref.read(businessFeatureProvider.notifier).updateFeatures(updated);
    }
  }
}