import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:intl/intl.dart';
import 'package:marco/controller/expense/add_expense_controller.dart';
import 'package:marco/model/expense/expense_type_model.dart';
import 'package:marco/model/expense/payment_types_model.dart';
import 'package:marco/model/expense/employee_selector_bottom_sheet.dart';
import 'package:marco/helpers/utils/base_bottom_sheet.dart';
import 'package:marco/helpers/utils/validators.dart';
import 'package:marco/helpers/widgets/my_spacing.dart';
import 'package:marco/helpers/widgets/my_snackbar.dart';
import 'package:marco/helpers/widgets/my_confirmation_dialog.dart';
import 'package:marco/helpers/widgets/expense/expense_form_widgets.dart';
import 'package:marco/view/project/create_project_bottom_sheet.dart';

/// Show bottom sheet wrapper
Future<T?> showAddExpenseBottomSheet<T>({
  bool isEdit = false,
  Map<String, dynamic>? existingExpense,
}) {
  return Get.bottomSheet<T>(
    _AddExpenseBottomSheet(isEdit: isEdit, existingExpense: existingExpense),
    isScrollControlled: true,
  );
}

/// Bottom sheet widget
class _AddExpenseBottomSheet extends StatefulWidget {
  final bool isEdit;
  final Map<String, dynamic>? existingExpense;

  const _AddExpenseBottomSheet({
    this.isEdit = false,
    this.existingExpense,
  });

  @override
  State<_AddExpenseBottomSheet> createState() => _AddExpenseBottomSheetState();
}

class _AddExpenseBottomSheetState extends State<_AddExpenseBottomSheet> {
  final AddExpenseController controller = Get.put(AddExpenseController());
  final _formKey = GlobalKey<FormState>();

  final GlobalKey _projectDropdownKey = GlobalKey();
  final GlobalKey _expenseTypeDropdownKey = GlobalKey();
  final GlobalKey _paymentModeDropdownKey = GlobalKey();

  @override
  Widget build(BuildContext context) {
    return Obx(
      () => Form(
        key: _formKey,
        child: BaseBottomSheet(
          title: widget.isEdit ? "Edit Expense" : "Add Expense",
          isSubmitting: controller.isSubmitting.value,
          onCancel: Get.back,
          onSubmit: _handleSubmit,
          child: SingleChildScrollView(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                _buildCreateProjectButton(),
                _buildProjectDropdown(),
                _gap(),
                _buildExpenseTypeDropdown(),
                if (controller.selectedExpenseType.value?.noOfPersonsRequired ==
                    true) ...[
                  _gap(),
                  _buildNumberField(
                    icon: Icons.people_outline,
                    title: "No. of Persons",
                    controller: controller.noOfPersonsController,
                    hint: "Enter No. of Persons",
                    validator: Validators.requiredField,
                  ),
                ],
                _gap(),
                _buildPaymentModeDropdown(),
                _gap(),
                _buildPaidBySection(),
                _gap(),
                _buildAmountField(),
                _gap(),
                _buildSupplierField(),
                _gap(),
                _buildTransactionDateField(),
                _gap(),
                _buildTransactionIdField(),
                _gap(),
                _buildLocationField(),
                _gap(),
                _buildAttachmentsSection(),
                _gap(),
                _buildDescriptionField(),
              ],
            ),
          ),
        ),
      ),
    );
  }

  /// 🟦 UI SECTION BUILDERS

  Widget _buildCreateProjectButton() {
    return Align(
      alignment: Alignment.centerRight,
      child: TextButton.icon(
        onPressed: () async {
          await Get.bottomSheet(const CreateProjectBottomSheet(),
              isScrollControlled: true);
          await controller.fetchGlobalProjects();
        },
        icon: const Icon(Icons.add, color: Colors.blue),
        label: const Text(
          "Create Project",
          style: TextStyle(color: Colors.blue, fontWeight: FontWeight.w600),
        ),
      ),
    );
  }

  Widget _buildProjectDropdown() {
    return _buildDropdownField<String>(
      icon: Icons.work_outline,
      title: "Project",
      requiredField: true,
      value: controller.selectedProject.value.isEmpty
          ? "Select Project"
          : controller.selectedProject.value,
      onTap: _showProjectSelector,
      dropdownKey: _projectDropdownKey,
    );
  }

  Widget _buildExpenseTypeDropdown() {
    return _buildDropdownField<ExpenseTypeModel>(
      icon: Icons.category_outlined,
      title: "Expense Type",
      requiredField: true,
      value:
          controller.selectedExpenseType.value?.name ?? "Select Expense Type",
      onTap: () => _showOptionList(
        controller.expenseTypes.toList(),
        (e) => e.name,
        (val) => controller.selectedExpenseType.value = val,
        _expenseTypeDropdownKey,
      ),
      dropdownKey: _expenseTypeDropdownKey,
    );
  }

  Widget _buildPaymentModeDropdown() {
    return _buildDropdownField<PaymentModeModel>(
      icon: Icons.payment,
      title: "Payment Mode",
      requiredField: true,
      value:
          controller.selectedPaymentMode.value?.name ?? "Select Payment Mode",
      onTap: () => _showOptionList(
        controller.paymentModes.toList(),
        (p) => p.name,
        (val) => controller.selectedPaymentMode.value = val,
        _paymentModeDropdownKey,
      ),
      dropdownKey: _paymentModeDropdownKey,
    );
  }

  Widget _buildPaidBySection() {
    return _buildTileSelector(
      icon: Icons.person_outline,
      title: "Paid By",
      required: true,
      displayText: controller.selectedPaidBy.value == null
          ? "Select Paid By"
          : '${controller.selectedPaidBy.value?.firstName ?? ''} ${controller.selectedPaidBy.value?.lastName ?? ''}',
      onTap: _showEmployeeList,
    );
  }

  Widget _buildAmountField() => _buildNumberField(
        icon: Icons.currency_rupee,
        title: "Amount",
        controller: controller.amountController,
        hint: "Enter Amount",
        validator: (v) =>
            Validators.isNumeric(v ?? "") ? null : "Enter valid amount",
      );

  Widget _buildSupplierField() => _buildTextField(
        icon: Icons.store_mall_directory_outlined,
        title: "Supplier Name/Transporter Name/Other",
        controller: controller.supplierController,
        hint: "Enter Supplier Name/Transporter Name or Other",
        validator: Validators.nameValidator,
      );

  Widget _buildTransactionIdField() {
    final paymentMode =
        controller.selectedPaymentMode.value?.name.toLowerCase() ?? '';
    final isRequired = paymentMode.isNotEmpty &&
        paymentMode != 'cash' &&
        paymentMode != 'cheque';

    return _buildTextField(
      icon: Icons.confirmation_number_outlined,
      title: "Transaction ID",
      controller: controller.transactionIdController,
      hint: "Enter Transaction ID",
      validator: (v) {
        if (isRequired) {
          if (v == null || v.isEmpty)
            return "Transaction ID is required for this payment mode";
          return Validators.transactionIdValidator(v);
        }
        return null;
      },
      requiredField: isRequired,
    );
  }

  Widget _buildTransactionDateField() {
    return Obx(() => _buildTileSelector(
          icon: Icons.calendar_today,
          title: "Transaction Date",
          required: true,
          displayText: controller.selectedTransactionDate.value == null
              ? "Select Transaction Date"
              : DateFormat('dd MMM yyyy')
                  .format(controller.selectedTransactionDate.value!),
          onTap: () => controller.pickTransactionDate(context),
        ));
  }

  Widget _buildLocationField() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const SectionTitle(icon: Icons.location_on_outlined, title: "Location"),
        MySpacing.height(6),
        TextFormField(
          controller: controller.locationController,
          decoration: InputDecoration(
            hintText: "Enter Location",
            filled: true,
            fillColor: Colors.grey.shade100,
            border: OutlineInputBorder(borderRadius: BorderRadius.circular(8)),
            contentPadding:
                const EdgeInsets.symmetric(horizontal: 12, vertical: 10),
            suffixIcon: controller.isFetchingLocation.value
                ? const Padding(
                    padding: EdgeInsets.all(12),
                    child: SizedBox(
                      width: 18,
                      height: 18,
                      child: CircularProgressIndicator(strokeWidth: 2),
                    ),
                  )
                : IconButton(
                    icon: const Icon(Icons.my_location),
                    tooltip: "Use Current Location",
                    onPressed: controller.fetchCurrentLocation,
                  ),
          ),
        ),
      ],
    );
  }

  Widget _buildAttachmentsSection() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const SectionTitle(
          icon: Icons.attach_file,
          title: "Attachments",
          requiredField: true,
        ),
        MySpacing.height(6),
        AttachmentsSection(
          attachments: controller.attachments,
          existingAttachments: controller.existingAttachments,
          onRemoveNew: controller.removeAttachment,
          onRemoveExisting: _confirmRemoveAttachment,
          onAdd: controller.pickAttachments,
        ),
      ],
    );
  }

  Widget _buildDescriptionField() => _buildTextField(
        icon: Icons.description_outlined,
        title: "Description",
        controller: controller.descriptionController,
        hint: "Enter Description",
        maxLines: 3,
        validator: Validators.requiredField,
      );

  /// 🟩 COMMON HELPERS

  Widget _gap([double h = 16]) => MySpacing.height(h);

  Widget _buildDropdownField<T>({
    required IconData icon,
    required String title,
    required bool requiredField,
    required String value,
    required VoidCallback onTap,
    required GlobalKey dropdownKey,
  }) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        SectionTitle(icon: icon, title: title, requiredField: requiredField),
        MySpacing.height(6),
        DropdownTile(key: dropdownKey, title: value, onTap: onTap),
      ],
    );
  }

  Widget _buildTextField({
    required IconData icon,
    required String title,
    required TextEditingController controller,
    String? hint,
    FormFieldValidator<String>? validator,
    bool requiredField = true,
    int maxLines = 1,
  }) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        SectionTitle(icon: icon, title: title, requiredField: requiredField),
        MySpacing.height(6),
        CustomTextField(
          controller: controller,
          hint: hint ?? "",
          validator: validator,
          maxLines: maxLines,
        ),
      ],
    );
  }

  Widget _buildNumberField({
    required IconData icon,
    required String title,
    required TextEditingController controller,
    String? hint,
    FormFieldValidator<String>? validator,
  }) {
    return _buildTextField(
      icon: icon,
      title: title,
      controller: controller,
      hint: hint,
      validator: validator,
    );
  }

  Widget _buildTileSelector({
    required IconData icon,
    required String title,
    required String displayText,
    required VoidCallback onTap,
    bool required = false,
  }) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        SectionTitle(icon: icon, title: title, requiredField: required),
        MySpacing.height(6),
        GestureDetector(
          onTap: onTap,
          child: TileContainer(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(displayText, style: const TextStyle(fontSize: 14)),
                const Icon(Icons.arrow_drop_down, size: 22),
              ],
            ),
          ),
        ),
      ],
    );
  }

  /// 🧰 LOGIC HELPERS

  Future<void> _showProjectSelector() async {
    final sortedProjects = controller.globalProjects.toList()
      ..sort((a, b) => a.toLowerCase().compareTo(b.toLowerCase()));

    const specialOption = 'Create New Project';
    final displayList = [...sortedProjects, specialOption];

    final selected = await showMenu<String>(
      context: context,
      position: _getPopupMenuPosition(_projectDropdownKey),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
      items: displayList.map((opt) {
        final isSpecial = opt == specialOption;
        return PopupMenuItem<String>(
          value: opt,
          child: isSpecial
              ? Row(
                  children: const [
                    Icon(Icons.add, color: Colors.blue),
                    SizedBox(width: 8),
                    Text(
                      specialOption,
                      style: TextStyle(
                        fontWeight: FontWeight.w600,
                        color: Colors.blue,
                      ),
                    ),
                  ],
                )
              : Text(
                  opt,
                  style: const TextStyle(
                    fontWeight: FontWeight.normal,
                    color: Colors.black,
                  ),
                ),
        );
      }).toList(),
    );

    if (selected == null) return;
    if (selected == specialOption) {
      controller.selectedProject.value = specialOption;
      await Get.bottomSheet(const CreateProjectBottomSheet(),
          isScrollControlled: true);
      await controller.fetchGlobalProjects();
      controller.selectedProject.value = "";
    } else {
      controller.selectedProject.value = selected;
    }
  }

  Future<void> _showEmployeeList() async {
    await showModalBottomSheet(
      context: context,
      isScrollControlled: true,
      backgroundColor: Colors.transparent,
      shape: const RoundedRectangleBorder(
        borderRadius: BorderRadius.vertical(top: Radius.circular(16)),
      ),
      builder: (_) => ReusableEmployeeSelectorBottomSheet(
        searchController: controller.employeeSearchController,
        searchResults: controller.employeeSearchResults,
        isSearching: controller.isSearchingEmployees,
        onSearch: controller.searchEmployees,
        onSelect: (emp) => controller.selectedPaidBy.value = emp,
      ),
    );
    controller.employeeSearchController.clear();
    controller.employeeSearchResults.clear();
  }

  Future<void> _confirmRemoveAttachment(item) async {
    await showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => ConfirmDialog(
        title: "Remove Attachment",
        message: "Are you sure you want to remove this attachment?",
        confirmText: "Remove",
        icon: Icons.delete,
        confirmColor: Colors.redAccent,
        onConfirm: () async {
          final index = controller.existingAttachments.indexOf(item);
          if (index != -1) {
            controller.existingAttachments[index]['isActive'] = false;
            controller.existingAttachments.refresh();
          }
          showAppSnackbar(
            title: 'Removed',
            message: 'Attachment has been removed.',
            type: SnackbarType.success,
          );
        },
      ),
    );
  }

  Future<void> _showOptionList<T>(
    List<T> options,
    String Function(T) getLabel,
    ValueChanged<T> onSelected,
    GlobalKey triggerKey,
  ) async {
    final selected = await showMenu<T>(
      context: context,
      position: _getPopupMenuPosition(triggerKey),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
      items: options
          .map((opt) => PopupMenuItem<T>(
                value: opt,
                child: Text(getLabel(opt)),
              ))
          .toList(),
    );
    if (selected != null) onSelected(selected);
  }

  RelativeRect _getPopupMenuPosition(GlobalKey key) {
    final RenderBox button =
        key.currentContext!.findRenderObject() as RenderBox;
    final RenderBox overlay =
        Overlay.of(context).context.findRenderObject() as RenderBox;
    final position = button.localToGlobal(Offset.zero, ancestor: overlay);
    return RelativeRect.fromLTRB(
      position.dx,
      position.dy + button.size.height,
      overlay.size.width - position.dx - button.size.width,
      0,
    );
  }

  bool _validateSelections() {
    if (controller.selectedProject.value.isEmpty) {
      return _error("Please select a project");
    }
    if (controller.selectedExpenseType.value == null) {
      return _error("Please select an expense type");
    }
    if (controller.selectedPaymentMode.value == null) {
      return _error("Please select a payment mode");
    }
    if (controller.selectedPaidBy.value == null) {
      return _error("Please select a person who paid");
    }
    if (controller.attachments.isEmpty &&
        controller.existingAttachments.isEmpty) {
      return _error("Please attach at least one document");
    }
    return true;
  }

  bool _error(String msg) {
    showAppSnackbar(title: "Error", message: msg, type: SnackbarType.error);
    return false;
  }

  void _handleSubmit() {
    if (_formKey.currentState!.validate() && _validateSelections()) {
      controller.submitOrUpdateExpense();
    } else {
      _error("Please fill all required fields correctly");
    }
  }
}