import 'package:flutter/material.dart';
import 'package:get/get.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';

/// 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();

  /// Show employee list
  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();
  }

  /// Generic option list
  Future<void> _showOptionList<T>(
    List<T> options,
    String Function(T) getLabel,
    ValueChanged<T> onSelected,
    GlobalKey triggerKey,
  ) async {
    final RenderBox button =
        triggerKey.currentContext!.findRenderObject() as RenderBox;
    final RenderBox overlay =
        Overlay.of(context).context.findRenderObject() as RenderBox;
    final position = button.localToGlobal(Offset.zero, ancestor: overlay);

    final selected = await showMenu<T>(
      context: context,
      position: RelativeRect.fromLTRB(
        position.dx,
        position.dy + button.size.height,
        overlay.size.width - position.dx - button.size.width,
        0,
      ),
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(8)),
      items: options
          .map((opt) => PopupMenuItem<T>(
                value: opt,
                child: Text(getLabel(opt)),
              ))
          .toList(),
    );

    if (selected != null) onSelected(selected);
  }

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

  void _showError(String msg) {
    showAppSnackbar(
      title: "Error",
      message: msg,
      type: SnackbarType.error,
    );
  }

  @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: () {
            if (_formKey.currentState!.validate() && _validateSelections()) {
              controller.submitOrUpdateExpense();
            } else {
              _showError("Please fill all required fields correctly");
            }
          },
          child: SingleChildScrollView(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                _buildDropdownField<String>(
                  icon: Icons.work_outline,
                  title: "Project",
                  requiredField: true,
                  value: controller.selectedProject.value.isEmpty
                      ? "Select Project"
                      : controller.selectedProject.value,
                  onTap: () => _showOptionList<String>(
                    controller.globalProjects.toList(),
                    (p) => p,
                    (val) => controller.selectedProject.value = val,
                    _projectDropdownKey,
                  ),
                  dropdownKey: _projectDropdownKey,
                ),
                _gap(),

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

                // Persons if required
                if (controller.selectedExpenseType.value?.noOfPersonsRequired ==
                    true) ...[
                  _gap(),
                  _buildTextFieldSection(
                    icon: Icons.people_outline,
                    title: "No. of Persons",
                    controller: controller.noOfPersonsController,
                    hint: "Enter No. of Persons",
                    keyboardType: TextInputType.number,
                    validator: Validators.requiredField,
                  ),
                ],
                _gap(),

                _buildTextFieldSection(
                  icon: Icons.confirmation_number_outlined,
                  title: "GST No.",
                  controller: controller.gstController,
                  hint: "Enter GST No.",
                ),
                _gap(),

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

                _buildPaidBySection(),
                _gap(),

                _buildTextFieldSection(
                  icon: Icons.currency_rupee,
                  title: "Amount",
                  controller: controller.amountController,
                  hint: "Enter Amount",
                  keyboardType: TextInputType.number,
                  validator: (v) => Validators.isNumeric(v ?? "")
                      ? null
                      : "Enter valid amount",
                ),
                _gap(),

                _buildTextFieldSection(
                  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,
                ),
                _gap(),

                _buildTextFieldSection(
                  icon: Icons.confirmation_number_outlined,
                  title: "Transaction ID",
                  controller: controller.transactionIdController,
                  hint: "Enter Transaction ID",
                  validator: (v) => (v != null && v.isNotEmpty)
                      ? Validators.transactionIdValidator(v)
                      : null,
                ),
                _gap(),

                _buildTransactionDateField(),
                _gap(),

                _buildLocationField(),
                _gap(),

                _buildAttachmentsSection(),
                _gap(),

                _buildTextFieldSection(
                  icon: Icons.description_outlined,
                  title: "Description",
                  controller: controller.descriptionController,
                  hint: "Enter Description",
                  maxLines: 3,
                  validator: Validators.requiredField,
                ),
              ],
            ),
          ),
        ),
      ),
    );
  }

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

  Widget _buildPaidBySection() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const SectionTitle(
            icon: Icons.person_outline, title: "Paid By", requiredField: true),
        MySpacing.height(6),
        GestureDetector(
          onTap: _showEmployeeList,
          child: TileContainer(
            child: Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(
                  controller.selectedPaidBy.value == null
                      ? "Select Paid By"
                      : '${controller.selectedPaidBy.value?.firstName ?? ''} ${controller.selectedPaidBy.value?.lastName ?? ''}',
                  style: const TextStyle(fontSize: 14),
                ),
                const Icon(Icons.arrow_drop_down, size: 22),
              ],
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildTransactionDateField() {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const SectionTitle(
            icon: Icons.calendar_today,
            title: "Transaction Date",
            requiredField: true),
        MySpacing.height(6),
        GestureDetector(
          onTap: () => controller.pickTransactionDate(context),
          child: AbsorbPointer(
            child: CustomTextField(
              controller: controller.transactionDateController,
              hint: "Select Transaction Date",
              validator: Validators.requiredField,
            ),
          ),
        ),
      ],
    );
  }

  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: (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,
                  );
                },
              ),
            );
          },
          onAdd: controller.pickAttachments,
        ),
      ],
    );
  }
}