import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import '../l10n/app_localizations.dart';
import '../models/tasks/barcode_task.dart';
import '../widgets/offline_banner.dart';

class BarcodeCaptureScreen extends StatefulWidget {
  final BarcodeTask task;
  final Function(List<String>) onBarcodesCompleted;

  const BarcodeCaptureScreen({super.key, required this.task, required this.onBarcodesCompleted});

  @override
  State<BarcodeCaptureScreen> createState() => _BarcodeCaptureScreenState();
}

class _BarcodeCaptureScreenState extends State<BarcodeCaptureScreen> {
  final List<String> _scannedBarcodes = [];
  final List<TextEditingController> _textControllers = [];
  MobileScannerController? _scannerController;
  bool _isMobilePlatform = false;
  bool _isScannerInitialized = false;

  @override
  void initState() {
    super.initState();
    _detectPlatformAndInit();
  }

  @override
  void dispose() {
    _scannerController?.dispose();
    for (final controller in _textControllers) {
      controller.dispose();
    }
    super.dispose();
  }

  void _detectPlatformAndInit() {
    // Determine if we're on a mobile platform
    if (kIsWeb) {
      _isMobilePlatform = false;
      _initializeDesktopMode();
    } else {
      switch (defaultTargetPlatform) {
        case TargetPlatform.android:
        case TargetPlatform.iOS:
          _isMobilePlatform = true;
          _initializeMobileScanner();
          break;
        case TargetPlatform.macOS:
        case TargetPlatform.windows:
        case TargetPlatform.linux:
          _isMobilePlatform = false;
          _initializeDesktopMode();
          break;
        default:
          _isMobilePlatform = false;
          _initializeDesktopMode();
      }
    }
  }

  void _initializeMobileScanner() {
    try {
      _scannerController = MobileScannerController();
      setState(() {
        _isScannerInitialized = true;
      });
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('${AppLocalizations.of(context).cameraError}: $e')));
      }
    }
  }

  void _initializeDesktopMode() {
    // Create text controllers for desktop input fields
    for (int i = 0; i < widget.task.maxBarcodeCount; i++) {
      _textControllers.add(TextEditingController());
    }
    setState(() {
      _isScannerInitialized = true;
    });
  }

  void _onBarcodeDetected(BarcodeCapture capture) {
    final List<Barcode> barcodes = capture.barcodes;
    for (final barcode in barcodes) {
      final String? code = barcode.rawValue;
      if (code != null && code.isNotEmpty && !_scannedBarcodes.contains(code)) {
        if (_scannedBarcodes.length < widget.task.maxBarcodeCount) {
          setState(() {
            _scannedBarcodes.add(code);
          });
        }
      }
    }
  }

  void _removeBarcode(int index) {
    setState(() {
      _scannedBarcodes.removeAt(index);
    });
  }

  void _finishTask() {
    final List<String> barcodes;
    if (_isMobilePlatform) {
      barcodes = _scannedBarcodes;
    } else {
      // Collect barcodes from text fields
      barcodes = [];
      for (final controller in _textControllers) {
        if (controller.text.trim().isNotEmpty) {
          barcodes.add(controller.text.trim());
        }
      }
    }

    // Navigate back to task view first
    Navigator.of(context).pop();

    // Then call the completion callback
    widget.onBarcodesCompleted(barcodes);
  }

  bool _canFinish() {
    if (_isMobilePlatform) {
      return _scannedBarcodes.length >= widget.task.minBarcodeCount;
    } else {
      int filledFields = 0;
      for (final controller in _textControllers) {
        if (controller.text.trim().isNotEmpty) {
          filledFields++;
        }
      }
      return filledFields >= widget.task.minBarcodeCount;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(appBar: AppBar(title: Text(AppLocalizations.of(context).barcodeScan), backgroundColor: Colors.deepPurple[100], leading: IconButton(icon: const Icon(Icons.arrow_back), onPressed: () => Navigator.of(context).pop())), body: Column(children: [OfflineBanner(), Expanded(child: _isScannerInitialized ? (_isMobilePlatform ? _buildMobileView() : _buildDesktopView()) : const Center(child: CircularProgressIndicator()))]));
  }

  Widget _buildMobileView() {
    return Column(
      children: [
        // Scanner view
        Expanded(
          flex: 3,
          child: Stack(
            children: [
              MobileScanner(controller: _scannerController, onDetect: _onBarcodeDetected),
              // Overlay with scanning frame
              Container(decoration: BoxDecoration(color: Colors.black.withValues(alpha: 0.5)), child: Center(child: Container(width: 250, height: 250, decoration: BoxDecoration(border: Border.all(color: Colors.white, width: 2), borderRadius: BorderRadius.circular(12)), child: Container(margin: const EdgeInsets.all(20), decoration: BoxDecoration(border: Border.all(color: Colors.green, width: 2), borderRadius: BorderRadius.circular(8)))))),
            ],
          ),
        ),
        // Scanned barcodes list
        Expanded(
          flex: 2,
          child: Container(
            padding: const EdgeInsets.all(16),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text('${AppLocalizations.of(context).scannedBarcodes} (${_scannedBarcodes.length}/${widget.task.maxBarcodeCount})', style: const TextStyle(fontSize: 16, fontWeight: FontWeight.bold)),
                const SizedBox(height: 8),
                Text('${AppLocalizations.of(context).minBarcodes} ${widget.task.minBarcodeCount} ${AppLocalizations.of(context).barcodesRequired}', style: TextStyle(fontSize: 14, color: Colors.grey[600])),
                const SizedBox(height: 16),
                Expanded(
                  child: ListView.builder(
                    itemCount: _scannedBarcodes.length,
                    itemBuilder: (context, index) {
                      return Card(child: ListTile(leading: const Icon(Icons.qr_code), title: Text(_scannedBarcodes[index]), trailing: IconButton(icon: const Icon(Icons.delete, color: Colors.red), onPressed: () => _removeBarcode(index))));
                    },
                  ),
                ),
                const SizedBox(height: 16),
                SizedBox(width: double.infinity, child: ElevatedButton(onPressed: _canFinish() ? _finishTask : null, style: ElevatedButton.styleFrom(padding: const EdgeInsets.symmetric(vertical: 16)), child: Text(AppLocalizations.of(context).finish))),
              ],
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildDesktopView() {
    return Padding(
      padding: const EdgeInsets.all(16),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(AppLocalizations.of(context).enterBarcode, style: const TextStyle(fontSize: 24, fontWeight: FontWeight.bold)),
          const SizedBox(height: 8),
          Text('${AppLocalizations.of(context).barcodeEnterDescription} (${widget.task.minBarcodeCount}-${widget.task.maxBarcodeCount})', style: TextStyle(fontSize: 16, color: Colors.grey[600])),
          const SizedBox(height: 24),
          Expanded(
            child: ListView.builder(
              itemCount: widget.task.maxBarcodeCount,
              itemBuilder: (context, index) {
                return Padding(
                  padding: const EdgeInsets.only(bottom: 12),
                  child: TextField(
                    controller: _textControllers[index],
                    decoration: InputDecoration(labelText: index < widget.task.minBarcodeCount ? AppLocalizations.of(context).barcodeNumberRequired(index + 1) : AppLocalizations.of(context).barcodeNumberOptional(index + 1), border: const OutlineInputBorder(), prefixIcon: const Icon(Icons.qr_code)),
                    onChanged: (value) {
                      setState(() {
                        // Trigger rebuild to update button state
                      });
                    },
                  ),
                );
              },
            ),
          ),
          const SizedBox(height: 16),
          SizedBox(width: double.infinity, child: ElevatedButton(onPressed: _canFinish() ? _finishTask : null, style: ElevatedButton.styleFrom(padding: const EdgeInsets.symmetric(vertical: 16)), child: Text(AppLocalizations.of(context).finish))),
        ],
      ),
    );
  }
}