import 'dart:io';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:path_provider/path_provider.dart';
import 'package:path/path.dart' as path;
import 'package:file_picker/file_picker.dart';
import '../../../core/services/upload_progress_service.dart';
import '../../../core/utils/logger.dart';
import '../../../core/utils/app_snackbar.dart';
import '../../../core/services/image_processing_service.dart';
import '../../../core/services/invoice_upload_service.dart';
import '../../../core/network/dio_client.dart';

class ScannerController extends GetxController {
  var capturedImages = <File>[].obs;
  var isProcessing = false.obs;
  var uploadProgress = 0.0.obs;
  var companies = <Map<String, dynamic>>[].obs;
  var isLoadingCompanies = false.obs;
  var currentBatchId = ''.obs;
  var processedImagesCount = 0.obs;
  var totalImagesCount = 0.obs;
  var isBatchDone = false.obs;
  var selectedCompanyId = ''.obs;
  var selectedCompanyName = ''.obs;

  final InvoiceUploadService _uploadService = InvoiceUploadService();
  final UploadProgressService _progressService =
      Get.find<UploadProgressService>();

  @override
  void onInit() {
    super.onInit();
    fetchCompanies();
    _initFcmListener();
  }

  void _initFcmListener() {
    FirebaseMessaging.onMessage.listen((RemoteMessage message) {
      final data = message.data;
      final type = data['type'];
      final batchId = data['batch_id'];

      if (batchId != currentBatchId.value) return;

      if (type == 'invoice_processed' || type == 'batch_progress') {
        processedImagesCount.value =
            int.tryParse(data['processed'].toString()) ?? 0;
        totalImagesCount.value = int.tryParse(data['total'].toString()) ?? 0;

        // Update global progress service
        _progressService.updateProcessingProgress(
            processedImagesCount.value, totalImagesCount.value);

        // If it's a single invoice, we can navigate directly
        if (totalImagesCount.value == 1 && data['invoice_id'] != null) {
          isBatchDone.value = true;
          _progressService.complete();
          
          // Open invoice details
          Get.toNamed('/invoice-detail', arguments: data['invoice_id']);
        }
      } else if (type == 'batch_complete') {
        isBatchDone.value = true;
        _progressService.complete();
        
        // Optionally navigate to invoices list or specific invoice
        if (data['invoice_id'] != null && data['invoice_id'].toString().isNotEmpty) {
           Get.toNamed('/invoice-detail', arguments: data['invoice_id']);
        }
      }
    });
  }

  Future<void> fetchCompanies() async {
    isLoadingCompanies.value = true;
    try {
      final res = await DioClient().client.get('companies');
      if (res.data['success'] == true && res.data['data'] != null) {
        companies.value = List<Map<String, dynamic>>.from(res.data['data']);
      }
    } catch (e) {
      AppLogger.error('Failed to fetch companies', e);
    } finally {
      isLoadingCompanies.value = false;
    }
  }

  Future<void> addImage(String imagePath) async {
    File originalFile = File(imagePath);
    capturedImages.add(originalFile);
    int index = capturedImages.length - 1;

    if (imagePath.toLowerCase().endsWith('.pdf')) {
      AppLogger.print('Added PDF file, skipping image processing: $imagePath');
      return;
    }

    ImageProcessingService.processInvoiceImage(originalFile)
        .then((processedFile) {
      if (processedFile != null && index < capturedImages.length) {
        capturedImages[index] = processedFile;
        AppLogger.print('Finished processing image in background.');
      }
    }).catchError((e) {
      AppLogger.error('Failed to process image in background', e);
    });
  }

  Future<void> pickPdfFile() async {
    try {
      FilePickerResult? result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowedExtensions: ['pdf'],
        allowMultiple: true,
      );

      if (result != null) {
        for (var file in result.files) {
          if (file.path != null) {
            addImage(file.path!);
          }
        }
        AppSnackbar.showSuccess('تمت الإضافة', 'تم استيراد ملفات الفواتير بنجاح');
      }
    } catch (e) {
      AppLogger.error('Failed to pick PDF', e);
      AppSnackbar.showError('خطأ', 'تعذر استيراد الملفات');
    }
  }

  void removeImage(int index) {
    if (index >= 0 && index < capturedImages.length) {
      capturedImages.removeAt(index);
    }
  }

  Future<void> uploadBatch() async {
    if (capturedImages.isEmpty) {
      AppSnackbar.showWarning('تنبيه', 'الرجاء تصوير فاتورة واحدة على الأقل');
      return;
    }
    if (selectedCompanyId.isEmpty) {
      AppSnackbar.showWarning('تنبيه', 'الرجاء اختيار الشركة أولاً');
      return;
    }

    try {
      isProcessing.value = true;
      uploadProgress.value = 0.0;

      AppLogger.print(
          'Uploading batch of ${capturedImages.length} images to company ${selectedCompanyId.value}...');

      // Start global progress
      _progressService.startUpload(selectedCompanyName.value, capturedImages.length);

      final batchId = await _uploadService.uploadBatch(
        companyId: selectedCompanyId.value,
        images: capturedImages,
        onProgress: (current, total) {
          uploadProgress.value = current / total;
          _progressService.updateProgress(uploadProgress.value, current);
        },
      );

      if (batchId != null) {
        currentBatchId.value = batchId;
        totalImagesCount.value = capturedImages.length;
        processedImagesCount.value = 0;

        // Clear scanner state and go back to dashboard
        capturedImages.clear();
        uploadProgress.value = 0.0;
        isProcessing.value = false;
        selectedCompanyId.value = '';
        selectedCompanyName.value = '';

        _progressService.startProcessing();
        Get.back(); // Go back to dashboard, progress will show in overlay
        AppSnackbar.showSuccess(
            'تم البدء', 'تم رفع الصور بنجاح، جاري استخراج البيانات في الخلفية');
            
        // Start polling for status (Reliable fallback for FCM)
        _startPolling(batchId);
      } else {
        _progressService.fail();
        AppSnackbar.showError('خطأ', 'فشل رفع الفواتير، يرجى المحاولة لاحقاً');
      }
    } catch (e) {
      _progressService.fail();
      AppLogger.error('Failed to upload batch', e);
      AppSnackbar.showError('خطأ', 'حدث خطأ غير متوقع أثناء الرفع');
    } finally {
      isProcessing.value = false;
    }
  }

  void _startPolling(String batchId) {
    bool firstPoll = true;
    
    // Check status periodically
    Future.doWhile(() async {
      // Wait before checking
      // First poll is after 8 seconds (AI takes time), subsequent are 5 seconds
      await Future.delayed(Duration(seconds: firstPoll ? 8 : 5));
      firstPoll = false;

      // If we are no longer interested in this batch or it's done, stop polling
      if (currentBatchId.value != batchId || isBatchDone.value) return false;

      try {
        final res = await DioClient().client.get('batches/status', queryParameters: {'batch_id': batchId});
        if (res.data['success'] == true) {
          final batch = res.data['data']['batch'];
          final items = res.data['data']['items'] as List;
          
          processedImagesCount.value = int.tryParse(batch['processed_images'].toString()) ?? 0;
          totalImagesCount.value = int.tryParse(batch['total_images'].toString()) ?? 1;
          
          _progressService.updateProcessingProgress(processedImagesCount.value, totalImagesCount.value);

          if (batch['status'] == 'done') {
            isBatchDone.value = true;
            _progressService.complete();
            
            // If it's a single invoice, find the invoice_id and navigate
            if (totalImagesCount.value == 1 && items.isNotEmpty) {
              final invoiceId = items.first['invoice_id'];
              if (invoiceId != null) {
                Get.toNamed('/invoice-detail', arguments: invoiceId);
              }
            }
            return false; // Stop polling
          }
        }
      } catch (e) {
        AppLogger.error('Polling error', e);
      }

      return true; // Continue polling
    });
  }

  void selectCompany(String id, String name) {
    selectedCompanyId.value = id;
    selectedCompanyName.value = name;
  }

  Future<String> getSavePath() async {
    final directory = await getTemporaryDirectory();
    final fileName = 'invoice_${DateTime.now().millisecondsSinceEpoch}.jpg';
    return path.join(directory.path, fileName);
  }
}