package screens

import (
	"fmt"

	"github.com/calmcacil/wg-admin/internal/config"
	"github.com/calmcacil/wg-admin/internal/validation"
	"github.com/calmcacil/wg-admin/internal/wireguard"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/huh"
	"github.com/charmbracelet/lipgloss"
)

// AddScreen is a form for adding new WireGuard clients
type AddScreen struct {
	form     *huh.Form
	quitting bool
}

// Styles
var (
	addTitleStyle = lipgloss.NewStyle().
			Foreground(lipgloss.Color("62")).
			Bold(true).
			MarginBottom(1)
	addHelpStyle = lipgloss.NewStyle().
			Foreground(lipgloss.Color("241")).
			MarginTop(1)
)

// NewAddScreen creates a new add screen
func NewAddScreen() *AddScreen {
	// Get default DNS from config
	cfg, err := config.LoadConfig()
	defaultDNS := "8.8.8.8, 8.8.4.4"
	if err == nil && cfg.DNSServers != "" {
		defaultDNS = cfg.DNSServers
	}

	// Create the form
	form := huh.NewForm(
		huh.NewGroup(
			huh.NewInput().
				Key("name").
				Title("Client Name").
				Description("Name for the new client (alphanumeric, -, _)").
				Placeholder("e.g., laptop-john").
				Validate(func(s string) error {
					return validation.ValidateClientName(s)
				}),

			huh.NewInput().
				Key("dns").
				Title("DNS Servers").
				Description("Comma-separated IPv4 addresses").
				Placeholder("e.g., 8.8.8.8, 8.8.4.4").
				Value(&defaultDNS).
				Validate(func(s string) error {
					return validation.ValidateDNSServers(s)
				}),

			huh.NewConfirm().
				Key("use_psk").
				Title("Use Preshared Key").
				Description("Enable additional security layer with a preshared key").
				Affirmative("Yes").
				Negative("No"),
		),
	)

	return &AddScreen{
		form:     form,
		quitting: false,
	}
}

// Init initializes the add screen
func (s *AddScreen) Init() tea.Cmd {
	return s.form.Init()
}

// Update handles messages for the add screen
func (s *AddScreen) Update(msg tea.Msg) (Screen, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "ctrl+c", "esc":
			// Cancel and return to list
			return nil, nil
		}
	}

	// Update the form
	form, cmd := s.form.Update(msg)
	if f, ok := form.(*huh.Form); ok {
		s.form = f
	}
	cmds = append(cmds, cmd)

	// Check if form is completed
	if s.form.State == huh.StateCompleted {
		name := s.form.GetString("name")
		dns := s.form.GetString("dns")
		usePSK := s.form.GetBool("use_psk")

		// Create the client
		return s, s.createClient(name, dns, usePSK)
	}

	return s, tea.Batch(cmds...)
}

// View renders the add screen
func (s *AddScreen) View() string {
	if s.quitting {
		return ""
	}

	content := lipgloss.JoinVertical(
		lipgloss.Left,
		addTitleStyle.Render("Add New WireGuard Client"),
		s.form.View(),
		addHelpStyle.Render("Press Enter to submit • Esc to cancel"),
	)

	return content
}

// createClient creates a new WireGuard client
func (s *AddScreen) createClient(name, dns string, usePSK bool) tea.Cmd {
	return func() tea.Msg {
		// Create the client via wireguard package
		err := wireguard.CreateClient(name, dns, usePSK)
		if err != nil {
			return errMsg{err: fmt.Errorf("failed to create client: %w", err)}
		}

		// Return success message
		return ClientCreatedMsg{
			Name: name,
		}
	}
}

// Messages

// ClientCreatedMsg is sent when a client is successfully created
type ClientCreatedMsg struct {
	Name string
}