import 'package:flutter/material.dart';
import 'package:mobile_scanner/mobile_scanner.dart';
import 'data_screen.dart';

class HomeScreen extends StatefulWidget {
  const HomeScreen({super.key});

  @override
  State<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  String? scannedData;
  List<String> scannedHistory = [];

  void _navigateToDataScreen() {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => DataScreen(scannedHistory: scannedHistory),
      ),
    );
  }

  void _openScanner() {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => ScannerScreen(
          onScan: (String code) {
            setState(() {
              scannedData = code;
              scannedHistory.add(code);
            });
          },
        ),
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Barcode Scanner'),
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
      ),
      body: Column(
        children: [
          Expanded(
            child: Column(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                Container(
                  padding: const EdgeInsets.all(20),
                  child: ElevatedButton.icon(
                    onPressed: _openScanner,
                    icon: const Icon(Icons.qr_code_scanner, size: 32),
                    label: const Text(
                      'Scan Barcode',
                      style: TextStyle(fontSize: 18),
                    ),
                    style: ElevatedButton.styleFrom(
                      padding: const EdgeInsets.symmetric(
                        horizontal: 40,
                        vertical: 15,
                      ),
                      backgroundColor: Theme.of(context).colorScheme.primary,
                      foregroundColor: Colors.white,
                    ),
                  ),
                ),
                const SizedBox(height: 30),
                if (scannedData != null)
                  Container(
                    margin: const EdgeInsets.symmetric(horizontal: 20),
                    padding: const EdgeInsets.all(20),
                    decoration: BoxDecoration(
                      color: Colors.grey[100],
                      borderRadius: BorderRadius.circular(10),
                      border: Border.all(color: Colors.grey[300]!),
                    ),
                    child: Column(
                      children: [
                        const Text(
                          'Last Scanned:',
                          style: TextStyle(
                            fontSize: 16,
                            fontWeight: FontWeight.bold,
                          ),
                        ),
                        const SizedBox(height: 10),
                        Text(
                          scannedData!,
                          style: const TextStyle(fontSize: 18),
                          textAlign: TextAlign.center,
                        ),
                      ],
                    ),
                  ),
                const SizedBox(height: 20),
                if (scannedHistory.isNotEmpty)
                  Expanded(
                    child: Container(
                      margin: const EdgeInsets.symmetric(horizontal: 20),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          Text(
                            'Scan History (${scannedHistory.length} items)',
                            style: const TextStyle(
                              fontSize: 16,
                              fontWeight: FontWeight.bold,
                            ),
                          ),
                          const SizedBox(height: 10),
                          Expanded(
                            child: ListView.builder(
                              itemCount: scannedHistory.length,
                              itemBuilder: (context, index) {
                                final reversedIndex = 
                                    scannedHistory.length - 1 - index;
                                return Card(
                                  child: ListTile(
                                    leading: CircleAvatar(
                                      child: Text('${reversedIndex + 1}'),
                                    ),
                                    title: Text(scannedHistory[reversedIndex]),
                                    subtitle: Text('Item ${reversedIndex + 1}'),
                                  ),
                                );
                              },
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
              ],
            ),
          ),
          Container(
            padding: const EdgeInsets.all(20),
            decoration: BoxDecoration(
              color: Colors.white,
              boxShadow: [
                BoxShadow(
                  color: Colors.grey.withOpacity(0.3),
                  spreadRadius: 1,
                  blurRadius: 5,
                  offset: const Offset(0, -3),
                ),
              ],
            ),
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                ElevatedButton.icon(
                  onPressed: scannedHistory.isEmpty ? null : () {
                    setState(() {
                      scannedHistory.clear();
                      scannedData = null;
                    });
                  },
                  icon: const Icon(Icons.clear_all),
                  label: const Text('Clear'),
                  style: ElevatedButton.styleFrom(
                    backgroundColor: Colors.red,
                    foregroundColor: Colors.white,
                  ),
                ),
                ElevatedButton.icon(
                  onPressed: scannedHistory.isEmpty ? null : _navigateToDataScreen,
                  icon: const Icon(Icons.list),
                  label: const Text('View All Data'),
                  style: ElevatedButton.styleFrom(
                    backgroundColor: Colors.green,
                    foregroundColor: Colors.white,
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }
}

class ScannerScreen extends StatefulWidget {
  final Function(String) onScan;

  const ScannerScreen({super.key, required this.onScan});

  @override
  State<ScannerScreen> createState() => _ScannerScreenState();
}

class _ScannerScreenState extends State<ScannerScreen> {
  MobileScannerController cameraController = MobileScannerController(
    formats: [BarcodeFormat.code128]
  );
  bool hasScanned = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Scan Barcode'),
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        actions: [
          // IconButton(
          //   icon: ValueListenableBuilder(
          //     valueListenable: cameraController.torchStateNotifier,
          //     builder: (context, state, child) {
          //       switch (state) {
          //         case TorchState.off:
          //           return const Icon(Icons.flash_off, color: Colors.grey);
          //         case TorchState.on:
          //           return const Icon(Icons.flash_on, color: Colors.yellow);
          //       }
          //     },
          //   ),
          //   onPressed: () => cameraController.toggleTorch(),
          // ),
          // IconButton(
          //   icon: ValueListenableBuilder(
          //     valueListenable: cameraController.cameraFacingState,
          //     builder: (context, state, child) {
          //       switch (state) {
          //         case CameraFacing.front:
          //           return const Icon(Icons.camera_front);
          //         case CameraFacing.back:
          //           return const Icon(Icons.camera_rear);
          //       }
          //     },
          //   ),
          //   onPressed: () => cameraController.switchCamera(),
          // ),
        ],
      ),
      body: Stack(
        children: [
          MobileScanner(
            controller: cameraController,
            onDetect: (capture) {
              if (!hasScanned) {
                final List<Barcode> barcodes = capture.barcodes;
                for (final barcode in barcodes) {
                  if (barcode.rawValue != null) {
                    hasScanned = true;
                    widget.onScan(barcode.rawValue!);
                    Navigator.pop(context);
                    break;
                  }
                }
              }
            },
          ),
          Center(
            child: Container(
              width: 300,
              height: 300,
              decoration: BoxDecoration(
                border: Border.all(
                  color: Colors.green,
                  width: 2,
                ),
                borderRadius: BorderRadius.circular(12),
              ),
            ),
          ),
          Positioned(
            bottom: 100,
            left: 0,
            right: 0,
            child: Center(
              child: Container(
                padding: const EdgeInsets.symmetric(horizontal: 20, vertical: 10),
                decoration: BoxDecoration(
                  color: Colors.black54,
                  borderRadius: BorderRadius.circular(8),
                ),
                child: const Text(
                  'Align barcode within the frame',
                  style: TextStyle(
                    color: Colors.white,
                    fontSize: 16,
                  ),
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

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