using System;
using System.Windows.Forms;
using C969Project.Data;
using C969Project.Data.Models;

namespace C969Project
{
    public partial class AddUpdateCustomerForm : Form
    {
        private Customer? _currentCustomer; 

        public AddUpdateCustomerForm()
        {
            InitializeComponent();
            saveButton.Click += SaveButton_Click;
            cancelButton.Click += CancelButton_Click;
        }

        public void InitAdd()
        {
            Text = "Add Customer";
            label1.Text = "Add Customer";
            
            nameTextBox.Text = string.Empty;
            addressTextBox.Text = string.Empty;
            cityTextBox.Text = string.Empty;
            zipTextBox.Text = string.Empty;
            phoneTextBox.Text = string.Empty;
            _currentCustomer = null;
            
            ShowDialog();
        }

        public void InitUpdate(Customer customer)
        {
            Text = "Update Customer";
            label1.Text = "Update Customer";

            _currentCustomer = customer;
            
            nameTextBox.Text = customer.CustomerName;
            var addr = DatabaseHelper.RetrieveAddress(customer.AddressId);
            if (addr != null)
            {
                addressTextBox.Text = addr.Address1;
                var city = DatabaseHelper.RetrieveCity(addr.CityId);
                if (city != null)
                {
                    cityTextBox.Text = city.CityName;
                }
                zipTextBox.Text = addr.PostalCode;
                phoneTextBox.Text = addr.Phone;
            }
            
            ShowDialog();
        }

        private void SaveButton_Click(object sender, EventArgs e)
        {
            if (string.IsNullOrWhiteSpace(nameTextBox.Text) ||
                string.IsNullOrWhiteSpace(addressTextBox.Text) ||
                string.IsNullOrWhiteSpace(cityTextBox.Text) ||
                string.IsNullOrWhiteSpace(zipTextBox.Text) ||
                string.IsNullOrWhiteSpace(phoneTextBox.Text))
            {
                MessageBox.Show("All fields must be filled out.", "Validation Error", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }

            if (!System.Text.RegularExpressions.Regex.IsMatch(phoneTextBox.Text.Trim(), @"^[\d-]+$"))
            {
                MessageBox.Show("Phone number can only contain digits and dashes.", "Validation Error", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                return;
            }


            string currentUser = AppState.CurrentUser.Username; 

            try
            {

                string countryName = "US";
                int currentCountryId = DatabaseHelper.GetCountryId(countryName);
                if (currentCountryId == 0)
                {
                    Country newCountry = new Country
                    {
                        CountryName = countryName,
                        CreateDate = DateTime.UtcNow,
                        CreatedBy = currentUser,
                        LastUpdate = DateTime.UtcNow,
                        LastUpdateBy = currentUser
                    };
                    currentCountryId = DatabaseHelper.AddCountry(newCountry);
                }

                int currentCityId = DatabaseHelper.GetCityId(cityTextBox.Text.Trim(), currentCountryId);
                if (currentCityId == 0)
                {
                    City newCity = new City
                    {
                        CityName = cityTextBox.Text.Trim(),
                        CountryID = currentCountryId,
                        CreateDate = DateTime.UtcNow,
                        CreatedBy = currentUser,
                        LastUpdate = DateTime.UtcNow,
                        LastUpdateBy = currentUser
                    };
                    currentCityId = DatabaseHelper.AddCity(newCity);
                }
                
                Address addressToSave;
                int finalAddressId;

                if (Text == "Add Customer")
                {
                    addressToSave = new Address
                    {
                        Address1 = addressTextBox.Text.Trim(),
                        Address2 = "",
                        CityId = currentCityId,
                        PostalCode = zipTextBox.Text.Trim(),
                        Phone = phoneTextBox.Text.Trim(),
                        CreateDate = DateTime.UtcNow,
                        CreatedBy = currentUser,
                        LastUpdate = DateTime.UtcNow,
                        LastUpdateBy = currentUser
                    };
                    finalAddressId = DatabaseHelper.AddAddress(addressToSave);
                }
                else 
                {
                    Address? existingAddress = DatabaseHelper.RetrieveAddress(_currentCustomer.AddressId);
                    if (existingAddress == null)
                    {
                        MessageBox.Show("Could not find existing address for update.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        return;
                    }

                    addressToSave = existingAddress;
                    addressToSave.Address1 = addressTextBox.Text.Trim();
                    addressToSave.Address2 = ""; 
                    addressToSave.CityId = currentCityId;
                    addressToSave.PostalCode = zipTextBox.Text.Trim();
                    addressToSave.Phone = phoneTextBox.Text.Trim();
                    addressToSave.LastUpdateBy = currentUser; 

                    DatabaseHelper.UpdateAddress(addressToSave);
                    finalAddressId = addressToSave.Id;
                }
                
                Customer customerToSave;
                if (Text == "Add Customer")
                {
                    customerToSave = new Customer
                    {
                        CustomerName = nameTextBox.Text.Trim(),
                        AddressId = finalAddressId,
                        Active = 1,
                        CreateDate = DateTime.UtcNow,
                        CreatedBy = currentUser,
                        LastUpdate = DateTime.UtcNow,
                        LastUpdateBy = currentUser
                    };
                    DatabaseHelper.AddCustomer(customerToSave);
                }
                else
                {
                    customerToSave = _currentCustomer;
                    customerToSave.CustomerName = nameTextBox.Text.Trim();
                    customerToSave.AddressId = finalAddressId;
                    customerToSave.LastUpdateBy = currentUser;

                    DatabaseHelper.UpdateCustomer(customerToSave);
                }

                MessageBox.Show("Customer saved successfully!", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
                DialogResult = DialogResult.OK;
                Close();
            }
            catch (Exception ex)
            {
                // TODO: Implement robust exception handling, logging, and user notification as per assignment A2b
                MessageBox.Show($"An error occurred while saving the customer: {ex.Message}", "Database Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private void CancelButton_Click(object sender, EventArgs e)
        {
            DialogResult = DialogResult.Cancel;
            Close();
        }
    }
}