package screens

import (
	"fmt"
	"time"

	"github.com/calmcacil/wg-admin/internal/tui/components"
	"github.com/calmcacil/wg-admin/internal/wireguard"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

// DetailScreen displays detailed information about a single WireGuard client
type DetailScreen struct {
	client        wireguard.Client
	status        string
	lastHandshake time.Time
	transferRx    string
	transferTx    string
	confirmModal  *components.DeleteConfirmModel
	showConfirm   bool
	configDisplay *components.ConfigDisplayModel
	showConfig    bool
}

// Styles
var (
	detailTitleStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("62")).
				Bold(true)
	detailSectionStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("241")).
				Bold(true).
				MarginTop(1)
	detailLabelStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("241")).
				Width(18)
	detailValueStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("255"))
	detailConnectedStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("46")).
				Bold(true)
	detailDisconnectedStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("196")).
				Bold(true)
	detailWarningStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("226")).
				Bold(true)
	detailHelpStyle = lipgloss.NewStyle().
			Foreground(lipgloss.Color("63")).
			MarginTop(1)
	detailErrorStyle = lipgloss.NewStyle().
				Foreground(lipgloss.Color("196")).
				MarginTop(1)
)

// NewDetailScreen creates a new detail screen for a client
func NewDetailScreen(client wireguard.Client) *DetailScreen {
	return &DetailScreen{
		client:      client,
		showConfirm: false,
	}
}

// Init initializes the detail screen
func (s *DetailScreen) Init() tea.Cmd {
	return s.loadClientStatus
}

// Update handles messages for the detail screen
func (s *DetailScreen) Update(msg tea.Msg) (Screen, tea.Cmd) {
	var cmd tea.Cmd

	// Handle confirmation modal
	if s.showConfirm && s.confirmModal != nil {
		_, cmd = s.confirmModal.Update(msg)

		// Handle confirmation result
		if !s.confirmModal.Visible {
			if s.confirmModal.IsConfirmed() {
				// User confirmed deletion
				return s, tea.Batch(s.deleteClient(), func() tea.Msg {
					return CloseDetailScreenMsg{}
				})
			}
			// User cancelled - close modal
			s.showConfirm = false
			return s, nil
		}

		return s, cmd
	}

	// Handle config display modal
	if s.showConfig && s.configDisplay != nil {
		_, cmd = s.configDisplay.Update(msg)

		// Handle modal close
		if !s.configDisplay.IsVisible() {
			s.showConfig = false
			return s, nil
		}

		return s, cmd
	}

	// Handle normal screen messages
	switch msg := msg.(type) {
	case clientStatusLoadedMsg:
		s.status = msg.status
		s.lastHandshake = msg.lastHandshake
		s.transferRx = msg.transferRx
		s.transferTx = msg.transferTx
	case tea.KeyMsg:
		switch msg.String() {
		case "b", "esc":
			// Return to list screen - signal parent to switch screens
			return nil, nil
		case "d":
			// Show delete confirmation
			s.confirmModal = components.NewDeleteConfirm(
				s.client.Name,
				80,
				24,
			)
			s.showConfirm = true
		case "c":
			// Show client configuration
			return s, s.loadConfig()
		}
	}

	return s, cmd
}

// View renders the detail screen
func (s *DetailScreen) View() string {
	// Handle config display modal
	if s.showConfig && s.configDisplay != nil {
		return s.configDisplay.View()
	}

	// Handle confirmation modal
	if s.showConfirm && s.confirmModal != nil {
		// Render underlying content dimmed
		content := s.renderContent()
		dimmedContent := lipgloss.NewStyle().
			Foreground(lipgloss.Color("244")).
			Render(content)

		// Overlay confirmation modal
		return lipgloss.JoinVertical(
			lipgloss.Left,
			dimmedContent,
			s.confirmModal.View(),
		)
	}

	return s.renderContent()
}

// renderContent renders the main detail screen content
func (s *DetailScreen) renderContent() string {
	statusText := s.status
	if s.status == wireguard.StatusConnected {
		statusText = detailConnectedStyle.Render(s.status)
	} else {
		statusText = detailDisconnectedStyle.Render(s.status)
	}

	// Build content
	content := lipgloss.JoinVertical(
		lipgloss.Left,
		detailTitleStyle.Render(fmt.Sprintf("Client Details: %s", s.client.Name)),
		"",
		s.renderField("Status", statusText),
		s.renderField("IPv4 Address", detailValueStyle.Render(s.client.IPv4)),
		s.renderField("IPv6 Address", detailValueStyle.Render(s.client.IPv6)),
		"",
		detailSectionStyle.Render("WireGuard Configuration"),
		s.renderField("Public Key", detailValueStyle.Render(s.client.PublicKey)),
		s.renderField("Preshared Key", detailValueStyle.Render(func() string {
			if s.client.HasPSK {
				return "✓ Configured"
			}
			return "Not configured"
		}())),
		"",
		detailSectionStyle.Render("Connection Info"),
		s.renderField("Last Handshake", detailValueStyle.Render(s.formatHandshake())),
		s.renderField("Transfer (Rx/Tx)", detailValueStyle.Render(fmt.Sprintf("%s / %s", s.transferRx, s.transferTx))),
		s.renderField("Config Path", detailValueStyle.Render(s.client.ConfigPath)),
		"",
	)

	// Add help text
	helpText := detailHelpStyle.Render("Actions: [d] Delete • [c] View Config • [b] Back")
	content = lipgloss.JoinVertical(lipgloss.Left, content, helpText)

	return content
}

// renderField renders a label-value pair
func (s *DetailScreen) renderField(label string, value string) string {
	return lipgloss.JoinHorizontal(lipgloss.Left,
		detailLabelStyle.Render(label),
		value,
	)
}

// formatHandshake formats the last handshake time
func (s *DetailScreen) formatHandshake() string {
	if s.lastHandshake.IsZero() {
		return "Never"
	}

	duration := time.Since(s.lastHandshake)
	if duration < time.Minute {
		return "Just now"
	} else if duration < time.Hour {
		return fmt.Sprintf("%d min ago", int(duration.Minutes()))
	} else if duration < 24*time.Hour {
		return fmt.Sprintf("%d hours ago", int(duration.Hours()))
	} else if duration < 7*24*time.Hour {
		return fmt.Sprintf("%d days ago", int(duration.Hours()/24))
	}
	return s.lastHandshake.Format("2006-01-02 15:04")
}

// loadClientStatus loads the current status of the client
func (s *DetailScreen) loadClientStatus() tea.Msg {
	peers, err := wireguard.GetAllPeers()
	if err != nil {
		return errMsg{err: err}
	}

	// Find peer by public key
	for _, peer := range peers {
		if peer.PublicKey == s.client.PublicKey {
			return clientStatusLoadedMsg{
				status:        peer.Status,
				lastHandshake: peer.LatestHandshake,
				transferRx:    peer.TransferRx,
				transferTx:    peer.TransferTx,
			}
		}
	}

	// Peer not found in active list
	return clientStatusLoadedMsg{
		status:        wireguard.StatusDisconnected,
		lastHandshake: time.Time{},
		transferRx:    "",
		transferTx:    "",
	}
}

// loadConfig loads and displays the client configuration
func (s *DetailScreen) loadConfig() tea.Cmd {
	return func() tea.Msg {
		config, err := wireguard.GetClientConfigContent(s.client.Name)
		if err != nil {
			return errMsg{fmt.Errorf("failed to load client config: %w", err)}
		}

		// Create or update config display modal
		if s.configDisplay == nil {
			s.configDisplay = components.NewConfigDisplay(config, 80, 24)
		} else {
			s.configDisplay.Show(config)
		}
		s.showConfig = true
		return nil
	}
}

// deleteClient deletes the client
func (s *DetailScreen) deleteClient() tea.Cmd {
	return func() tea.Msg {
		err := wireguard.DeleteClient(s.client.Name)
		if err != nil {
			return errMsg{fmt.Errorf("failed to delete client: %w", err)}
		}
		return ClientDeletedMsg{
			Name: s.client.Name,
		}
	}
}

// Messages

// clientStatusLoadedMsg is sent when client status is loaded
type clientStatusLoadedMsg struct {
	status        string
	lastHandshake time.Time
	transferRx    string
	transferTx    string
}