package screens

import (
	"fmt"
	"strings"

	"github.com/calmcacil/wg-admin/internal/wireguard"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
	"github.com/mdp/qrterminal/v3"
)

// QRScreen displays a QR code for a WireGuard client configuration
type QRScreen struct {
	clientName    string
	configContent string
	qrCode        string
	inlineMode    bool
	width, height int
	errorMsg      string
}

// NewQRScreen creates a new QR screen for displaying client config QR codes
func NewQRScreen(clientName string) *QRScreen {
	return &QRScreen{
		clientName: clientName,
		inlineMode: true, // Start in inline mode
	}
}

// Init initializes the QR screen
func (s *QRScreen) Init() tea.Cmd {
	return s.loadConfig
}

// Update handles messages for the QR screen
func (s *QRScreen) Update(msg tea.Msg) (Screen, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "q", "escape":
			// Return to list screen (parent should handle this)
			return nil, nil
		case "f":
			// Toggle between inline and fullscreen mode
			s.inlineMode = !s.inlineMode
			s.generateQRCode()
		}
	case tea.WindowSizeMsg:
		// Handle terminal resize
		s.width = msg.Width
		s.height = msg.Height
		s.generateQRCode()
	case configLoadedMsg:
		s.configContent = msg.content
		s.generateQRCode()
	case ErrMsg:
		s.errorMsg = msg.Err.Error()
	}

	return s, nil
}

// View renders the QR screen
func (s *QRScreen) View() string {
	if s.errorMsg != "" {
		return s.renderError()
	}
	if s.qrCode == "" {
		return "Loading QR code..."
	}
	return s.renderQR()
}

// loadConfig loads the client configuration
func (s *QRScreen) loadConfig() tea.Msg {
	content, err := wireguard.GetClientConfigContent(s.clientName)
	if err != nil {
		return ErrMsg{Err: err}
	}
	return configLoadedMsg{content: content}
}

// generateQRCode generates the QR code based on current mode and terminal size
func (s *QRScreen) generateQRCode() {
	if s.configContent == "" {
		return
	}

	// Generate QR code and capture output
	var builder strings.Builder

	// Generate ANSI QR code using half-block characters
	qrterminal.GenerateHalfBlock(s.configContent, qrterminal.L, &builder)

	s.qrCode = builder.String()
}

// renderQR renders the QR code with styling
func (s *QRScreen) renderQR() string {
	styleTitle := lipgloss.NewStyle().
		Foreground(lipgloss.Color("62")).
		Bold(true).
		MarginBottom(1)

	styleHelp := lipgloss.NewStyle().
		Foreground(lipgloss.Color("241")).
		MarginTop(1)

	styleQR := lipgloss.NewStyle().
		MarginLeft(2)

	title := styleTitle.Render(fmt.Sprintf("QR Code: %s", s.clientName))
	help := "Press [f] to toggle fullscreen • Press [q/Escape] to return"

	return title + "\n\n" + styleQR.Render(s.qrCode) + "\n" + styleHelp.Render(help)
}

// renderError renders an error message
func (s *QRScreen) renderError() string {
	styleError := lipgloss.NewStyle().
		Foreground(lipgloss.Color("196")).
		Bold(true)

	styleHelp := lipgloss.NewStyle().
		Foreground(lipgloss.Color("241")).
		MarginTop(1)

	title := styleError.Render("Error")
	message := s.errorMsg
	help := "Press [q/Escape] to return"

	return title + "\n\n" + message + "\n" + styleHelp.Render(help)
}

// Messages

// configLoadedMsg is sent when the client configuration is loaded
type configLoadedMsg struct {
	content string
}