import 'dart:convert';
import 'dart:io';

import 'package:file_picker/file_picker.dart';
import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:geocoding/geocoding.dart';
import 'package:geolocator/geolocator.dart';
import 'package:intl/intl.dart';

import 'package:marco/controller/expense/expense_screen_controller.dart';
import 'package:marco/helpers/services/api_service.dart';
import 'package:marco/helpers/services/app_logger.dart';
import 'package:marco/helpers/widgets/my_snackbar.dart';
import 'package:marco/model/employee_model.dart';
import 'package:marco/model/expense/expense_type_model.dart';
import 'package:marco/model/expense/payment_types_model.dart';
import 'package:mime/mime.dart';

class AddExpenseController extends GetxController {
  // --- Text Controllers ---
  final amountController = TextEditingController();
  final descriptionController = TextEditingController();
  final supplierController = TextEditingController();
  final transactionIdController = TextEditingController();
  final gstController = TextEditingController();
  final locationController = TextEditingController();
  final transactionDateController = TextEditingController();
  final noOfPersonsController = TextEditingController();

  final employeeSearchController = TextEditingController();

  // --- Reactive State ---
  final isLoading = false.obs;
  final isSubmitting = false.obs;
  final isFetchingLocation = false.obs;
  final isEditMode = false.obs;
  final isSearchingEmployees = false.obs;

  // --- Dropdown Selections & Data ---
  final selectedPaymentMode = Rxn<PaymentModeModel>();
  final selectedExpenseType = Rxn<ExpenseTypeModel>();
  final selectedPaidBy = Rxn<EmployeeModel>();
  final selectedProject = ''.obs;
  final selectedTransactionDate = Rxn<DateTime>();

  final attachments = <File>[].obs;
  final existingAttachments = <Map<String, dynamic>>[].obs;
  final globalProjects = <String>[].obs;
  final projectsMap = <String, String>{}.obs;

  final expenseTypes = <ExpenseTypeModel>[].obs;
  final paymentModes = <PaymentModeModel>[].obs;
  final allEmployees = <EmployeeModel>[].obs;
  final employeeSearchResults = <EmployeeModel>[].obs;

  String? editingExpenseId;

  final expenseController = Get.find<ExpenseController>();

  @override
  void onInit() {
    super.onInit();
    fetchMasterData();
    fetchGlobalProjects();
    employeeSearchController.addListener(() {
      searchEmployees(employeeSearchController.text);
    });
  }

  @override
  void onClose() {
    for (var c in [
      amountController,
      descriptionController,
      supplierController,
      transactionIdController,
      gstController,
      locationController,
      transactionDateController,
      noOfPersonsController,
      employeeSearchController,
    ]) {
      c.dispose();
    }
    super.onClose();
  }

  // --- Employee Search ---
  Future<void> searchEmployees(String query) async {
    if (query.trim().isEmpty) return employeeSearchResults.clear();
    isSearchingEmployees.value = true;
    try {
      final data =
          await ApiService.searchEmployeesBasic(searchString: query.trim());
      employeeSearchResults.assignAll(
        (data ?? []).map((e) => EmployeeModel.fromJson(e)),
      );
    } catch (e) {
      logSafe("Error searching employees: $e", level: LogLevel.error);
      employeeSearchResults.clear();
    } finally {
      isSearchingEmployees.value = false;
    }
  }

  // --- Form Population: Edit Mode ---
  Future<void> populateFieldsForEdit(Map<String, dynamic> data) async {
    isEditMode.value = true;
    editingExpenseId = '${data['id']}';

    selectedProject.value = data['projectName'] ?? '';
    amountController.text = data['amount']?.toString() ?? '';
    supplierController.text = data['supplerName'] ?? '';
    descriptionController.text = data['description'] ?? '';
    transactionIdController.text = data['transactionId'] ?? '';
    locationController.text = data['location'] ?? '';
    noOfPersonsController.text = (data['noOfPersons'] ?? 0).toString();

    // Transaction Date
    if (data['transactionDate'] != null) {
      try {
        final parsed = DateTime.parse(data['transactionDate']);
        selectedTransactionDate.value = parsed;
        transactionDateController.text =
            DateFormat('dd-MM-yyyy').format(parsed);
      } catch (_) {
        selectedTransactionDate.value = null;
        transactionDateController.clear();
      }
    }

    // Dropdown
    selectedExpenseType.value =
        expenseTypes.firstWhereOrNull((e) => e.id == data['expensesTypeId']);
    selectedPaymentMode.value =
        paymentModes.firstWhereOrNull((e) => e.id == data['paymentModeId']);

    // Paid By
    final paidById = '${data['paidById']}';
    selectedPaidBy.value =
        allEmployees.firstWhereOrNull((e) => e.id.trim() == paidById.trim());
    if (selectedPaidBy.value == null && data['paidByFirstName'] != null) {
      await searchEmployees(
          '${data['paidByFirstName']} ${data['paidByLastName']}');
      selectedPaidBy.value = employeeSearchResults
          .firstWhereOrNull((e) => e.id.trim() == paidById.trim());
    }

    // Attachments
    existingAttachments.clear();
    if (data['attachments'] is List) {
      existingAttachments.addAll(
        List<Map<String, dynamic>>.from(data['attachments'])
            .map((e) => {...e, 'isActive': true}),
      );
    }

    _logPrefilledData();
  }

  void _logPrefilledData() {
    logSafe('--- Prefilled Expense Data ---', level: LogLevel.info);
    [
      'ID: $editingExpenseId',
      'Project: ${selectedProject.value}',
      'Amount: ${amountController.text}',
      'Supplier: ${supplierController.text}',
      'Description: ${descriptionController.text}',
      'Transaction ID: ${transactionIdController.text}',
      'Location: ${locationController.text}',
      'Transaction Date: ${transactionDateController.text}',
      'No. of Persons: ${noOfPersonsController.text}',
      'Expense Type: ${selectedExpenseType.value?.name}',
      'Payment Mode: ${selectedPaymentMode.value?.name}',
      'Paid By: ${selectedPaidBy.value?.name}',
      'Attachments: ${attachments.length}',
      'Existing Attachments: ${existingAttachments.length}',
    ].forEach((str) => logSafe(str, level: LogLevel.info));
  }

  // --- Pickers ---
  Future<void> pickTransactionDate(BuildContext context) async {
    final pickedDate = await showDatePicker(
      context: context,
      initialDate: selectedTransactionDate.value ?? DateTime.now(),
      firstDate: DateTime(DateTime.now().year - 5),
      lastDate: DateTime.now(),
    );

    if (pickedDate != null) {
      final now = DateTime.now(); 
      final finalDateTime = DateTime(
        pickedDate.year,
        pickedDate.month,
        pickedDate.day,
        now.hour,
        now.minute,
        now.second,
      );

      selectedTransactionDate.value = finalDateTime;
      transactionDateController.text =
          DateFormat('dd MMM yyyy').format(finalDateTime);
    }
  }

  Future<void> pickAttachments() async {
    try {
      final result = await FilePicker.platform.pickFiles(
        type: FileType.custom,
        allowedExtensions: ['jpg', 'jpeg', 'png', 'pdf', 'doc', 'docx'],
        allowMultiple: true,
      );
      if (result != null) {
        attachments
            .addAll(result.paths.whereType<String>().map((path) => File(path)));
      }
    } catch (e) {
      _errorSnackbar("Attachment error: $e");
    }
  }

  void removeAttachment(File file) => attachments.remove(file);

  // --- Location ---
  Future<void> fetchCurrentLocation() async {
    isFetchingLocation.value = true;
    try {
      final permission = await _ensureLocationPermission();
      if (!permission) return;

      final position = await Geolocator.getCurrentPosition();
      final placemarks =
          await placemarkFromCoordinates(position.latitude, position.longitude);

      locationController.text = placemarks.isNotEmpty
          ? [
              placemarks.first.name,
              placemarks.first.street,
              placemarks.first.locality,
              placemarks.first.administrativeArea,
              placemarks.first.country
            ].where((e) => e?.isNotEmpty == true).join(", ")
          : "${position.latitude}, ${position.longitude}";
    } catch (e) {
      _errorSnackbar("Location error: $e");
    } finally {
      isFetchingLocation.value = false;
    }
  }

  Future<bool> _ensureLocationPermission() async {
    var permission = await Geolocator.checkPermission();
    if (permission == LocationPermission.denied ||
        permission == LocationPermission.deniedForever) {
      permission = await Geolocator.requestPermission();
      if (permission == LocationPermission.denied ||
          permission == LocationPermission.deniedForever) {
        _errorSnackbar("Location permission denied.");
        return false;
      }
    }
    if (!await Geolocator.isLocationServiceEnabled()) {
      _errorSnackbar("Location service disabled.");
      return false;
    }
    return true;
  }

  // --- Data Fetching ---
  Future<void> loadMasterData() async =>
      await Future.wait([fetchMasterData(), fetchGlobalProjects()]);

  Future<void> fetchMasterData() async {
    try {
      final types = await ApiService.getMasterExpenseTypes();
      if (types is List)
        expenseTypes.value =
            types.map((e) => ExpenseTypeModel.fromJson(e)).toList();

      final modes = await ApiService.getMasterPaymentModes();
      if (modes is List)
        paymentModes.value =
            modes.map((e) => PaymentModeModel.fromJson(e)).toList();
    } catch (_) {
      _errorSnackbar("Failed to fetch master data");
    }
  }

  Future<void> fetchGlobalProjects() async {
    try {
      final response = await ApiService.getGlobalProjects();
      if (response != null) {
        final names = <String>[];
        for (var item in response) {
          final name = item['name']?.toString().trim(),
              id = item['id']?.toString().trim();
          if (name != null && id != null) {
            projectsMap[name] = id;
            names.add(name);
          }
        }
        globalProjects.assignAll(names);
      }
    } catch (e) {
      logSafe("Error fetching projects: $e", level: LogLevel.error);
    }
  }

  // --- Submission ---
  Future<void> submitOrUpdateExpense() async {
    if (isSubmitting.value) return;
    isSubmitting.value = true;
    try {
      final validationMsg = validateForm();
      if (validationMsg.isNotEmpty) {
        _errorSnackbar(validationMsg, "Missing Fields");
        return;
      }

      final payload = await _buildExpensePayload();

      final success = isEditMode.value && editingExpenseId != null
          ? await ApiService.editExpenseApi(
              expenseId: editingExpenseId!, payload: payload)
          : await ApiService.createExpenseApi(
              projectId: payload['projectId'],
              expensesTypeId: payload['expensesTypeId'],
              paymentModeId: payload['paymentModeId'],
              paidById: payload['paidById'],
              transactionDate: DateTime.parse(payload['transactionDate']),
              transactionId: payload['transactionId'],
              description: payload['description'],
              location: payload['location'],
              supplerName: payload['supplerName'],
              amount: payload['amount'],
              noOfPersons: payload['noOfPersons'],
              billAttachments: payload['billAttachments'],
            );

      if (success) {
        await expenseController.fetchExpenses();
        Get.back();
        showAppSnackbar(
          title: "Success",
          message:
              "Expense ${isEditMode.value ? 'updated' : 'created'} successfully!",
          type: SnackbarType.success,
        );
      } else {
        _errorSnackbar("Operation failed. Try again.");
      }
    } catch (e) {
      _errorSnackbar("Unexpected error: $e");
    } finally {
      isSubmitting.value = false;
    }
  }

  Future<Map<String, dynamic>> _buildExpensePayload() async {
    final now = DateTime.now();
    final existingAttachmentPayloads = existingAttachments
        .map((e) => {
              "documentId": e['documentId'],
              "fileName": e['fileName'],
              "contentType": e['contentType'],
              "fileSize": 0,
              "description": "",
              "url": e['url'],
              "isActive": e['isActive'] ?? true,
              "base64Data": e['isActive'] == false ? null : e['base64Data'],
            })
        .toList();

    final newAttachmentPayloads =
        await Future.wait(attachments.map((file) async {
      final bytes = await file.readAsBytes();
      return {
        "fileName": file.path.split('/').last,
        "base64Data": base64Encode(bytes),
        "contentType": lookupMimeType(file.path) ?? 'application/octet-stream',
        "fileSize": await file.length(),
        "description": "",
      };
    }));

    final type = selectedExpenseType.value!;
    return {
      if (isEditMode.value && editingExpenseId != null) "id": editingExpenseId,
      "projectId": projectsMap[selectedProject.value]!,
      "expensesTypeId": type.id,
      "paymentModeId": selectedPaymentMode.value!.id,
      "paidById": selectedPaidBy.value!.id,
      "transactionDate": (selectedTransactionDate.value?.toUtc() ?? now.toUtc())
          .toIso8601String(),
      "transactionId": transactionIdController.text,
      "description": descriptionController.text,
      "location": locationController.text,
      "supplerName": supplierController.text,
      "amount": double.parse(amountController.text.trim()),
      "noOfPersons": type.noOfPersonsRequired == true
          ? int.tryParse(noOfPersonsController.text.trim()) ?? 0
          : 0,
      "billAttachments": [
        ...existingAttachmentPayloads,
        ...newAttachmentPayloads
      ],
    };
  }

  String validateForm() {
    final missing = <String>[];

    if (selectedProject.value.isEmpty) missing.add("Project");
    if (selectedExpenseType.value == null) missing.add("Expense Type");
    if (selectedPaymentMode.value == null) missing.add("Payment Mode");
    if (selectedPaidBy.value == null) missing.add("Paid By");
    if (amountController.text.trim().isEmpty) missing.add("Amount");
    if (descriptionController.text.trim().isEmpty) missing.add("Description");

    // Date Required
    if (selectedTransactionDate.value == null) missing.add("Transaction Date");
    if (selectedTransactionDate.value != null &&
        selectedTransactionDate.value!.isAfter(DateTime.now())) {
      missing.add("Valid Transaction Date");
    }

    final amount = double.tryParse(amountController.text.trim());
    if (amount == null) missing.add("Valid Amount");

    // Attachment: at least one required at all times
    bool hasActiveExisting =
        existingAttachments.any((e) => e['isActive'] != false);
    if (attachments.isEmpty && !hasActiveExisting) missing.add("Attachment");

    return missing.isEmpty ? '' : "Please provide: ${missing.join(', ')}.";
  }

  // --- Snackbar Helper ---
  void _errorSnackbar(String msg, [String title = "Error"]) => showAppSnackbar(
        title: title,
        message: msg,
        type: SnackbarType.error,
      );
}