using C969Project.Data;
using C969Project.Data.Models;

namespace C969Project;

public partial class AddOrUpdateAppointmentForm : Form
{
    public event EventHandler UpdateAppointmentsList;
    
    private Appointment? _currentAppointment;
    
    private List<string> _appointmentTypes = new ()
    {
        "Scrum",
        "Presentation",
        "Other"
    };

    private List<Customer> _customers = new();
    
    public AddOrUpdateAppointmentForm()
    {
        InitializeComponent();
        RefreshComponents();
        
        typeComboBox.DataSource = _appointmentTypes;
        saveButton.Click += SaveButton_Click;
        cancelButton.Click += (s, e) => Close();
    }
    
    private void RefreshComponents()
    {
        _customers.Clear();
        _customers.AddRange(DatabaseHelper.RetrieveCustomers());
        customerComboBox.DataSource = _customers;
    }

    public void InitAdd()
    {
        label1.Text = "Add New Appointment";
        _currentAppointment = null;
        
        titleTextBox.Text = string.Empty;
        descriptionTextBox.Text = string.Empty;
        locationTextBox.Text = string.Empty;
        contactTextBox.Text = string.Empty;
        textBoxUrl.Text = string.Empty;
        typeComboBox.SelectedIndex = -1;
        customerComboBox.SelectedIndex = -1;
        startPickerDate.Value = DateTime.Now.Date;
        startPickerTime.Value = DateTime.Now;    
        endPickerDate.Value = DateTime.Now.Date;  
        endPickerTime.Value = DateTime.Now.AddHours(1);
        
        ShowDialog();
    }

    public void InitUpdate(Appointment appointment)
    {
        label1.Text = "Update Appointment";
        _currentAppointment = appointment;
        
        titleTextBox.Text = appointment.Title;
        descriptionTextBox.Text = appointment.Description;
        locationTextBox.Text = appointment.Location;
        contactTextBox.Text = appointment.Contact;
        textBoxUrl.Text = appointment.Url;
        
        typeComboBox.SelectedItem = appointment.AppointmentType;
        customerComboBox.SelectedItem = _customers.FirstOrDefault(c => c.CustomerId == appointment.CustomerId);
        
        startPickerDate.Value = appointment.Start.ToLocalTime().Date;
        startPickerTime.Value = appointment.Start.ToLocalTime();
        endPickerDate.Value = appointment.End.ToLocalTime().Date;
        endPickerTime.Value = appointment.End.ToLocalTime();

        ShowDialog();
    }
    
    private bool ValidateForm()
    {
        if (string.IsNullOrWhiteSpace(titleTextBox.Text) ||
            string.IsNullOrWhiteSpace(descriptionTextBox.Text) ||
            string.IsNullOrWhiteSpace(locationTextBox.Text) ||
            string.IsNullOrWhiteSpace(contactTextBox.Text) ||
            string.IsNullOrWhiteSpace(textBoxUrl.Text) ||
            typeComboBox.SelectedIndex == -1 ||
            customerComboBox.SelectedIndex == -1)
        {
            MessageBox.Show("All fields must be filled out.", "Validation Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return false;
        }
    
        DateTime start = startPickerDate.Value.Date.Add(startPickerTime.Value.TimeOfDay).ToUniversalTime();
        DateTime end = endPickerDate.Value.Date.Add(endPickerTime.Value.TimeOfDay).ToUniversalTime();
    
        if (start >= end)
        {
            MessageBox.Show("Start time must be before end time.", "Validation Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return false;
        }
    
        TimeZoneInfo estZone = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
        DateTime startEST = TimeZoneInfo.ConvertTimeFromUtc(start, estZone);
        DateTime endEST = TimeZoneInfo.ConvertTimeFromUtc(end, estZone);
    
        if (startEST.Hour < 9 || endEST.Hour > 17 || startEST.DayOfWeek == DayOfWeek.Saturday || startEST.DayOfWeek == DayOfWeek.Sunday)
        {
            MessageBox.Show("Appointments must be scheduled during business hours (9:00 AM - 5:00 PM EST, Monday-Friday).", "Validation Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            return false;
        }
    
        var appointments = DatabaseHelper.RetrieveAppointments(AppState.CurrentUser.UserId);
        foreach (var appt in appointments)
        {
            if (_currentAppointment == null || appt.AppointmentId != _currentAppointment.AppointmentId)
            {
                if (start < appt.End && end > appt.Start)
                {
                    MessageBox.Show("Appointment times cannot overlap with existing appointments.", "Validation Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return false;
                }
            }
        }
    
        return true;
    }
    
    private void SaveButton_Click(object? sender, EventArgs e)
    {
        if (!ValidateForm())
            return;
    
        try
        {
            var selectedCustomer = (Customer)customerComboBox.SelectedItem!;
            var appointment = new Appointment
            {
                AppointmentId = _currentAppointment?.AppointmentId ?? 0,
                CustomerId = selectedCustomer.CustomerId,
                UserId = AppState.CurrentUser.UserId,
                Title = titleTextBox.Text.Trim(),
                Description = descriptionTextBox.Text.Trim(),
                Location = locationTextBox.Text.Trim(),
                Contact = contactTextBox.Text.Trim(),
                AppointmentType = typeComboBox.SelectedItem!.ToString()!,
                Url = textBoxUrl.Text.Trim(),
                Start = startPickerDate.Value.Date.Add(startPickerTime.Value.TimeOfDay).ToUniversalTime(),
                End = endPickerDate.Value.Date.Add(endPickerTime.Value.TimeOfDay).ToUniversalTime(),
                CreateDate = DateTime.UtcNow,
                CreatedBy = AppState.CurrentUser.Username,
                LastUpdate = DateTime.UtcNow,
                LastUpdateBy = AppState.CurrentUser.Username
            };
    
            if (_currentAppointment == null)
            {
                DatabaseHelper.AddAppointment(appointment);
                MessageBox.Show("Appointment added successfully.", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            else
            {
                DatabaseHelper.UpdateAppointment(appointment);
                MessageBox.Show("Appointment updated successfully.", "Success", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
    
            DialogResult = DialogResult.OK;
            UpdateAppointmentsList?.Invoke(this, EventArgs.Empty);
            Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show($"An error occurred while saving the appointment:\n{ex.Message}", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

}