package main

import (
	"fmt"
	"io"

	"github.com/charmbracelet/bubbles/key"
	"github.com/charmbracelet/bubbles/list"
	"github.com/charmbracelet/lipgloss"
)

// Constants for UI dimensions
const (
	minEmailWidth    = 50
	maxEmailWidth    = 70
	minLoadingWidth  = 40
	maxLoadingWidth  = 60
	inputCharLimit   = 256
	inputWidth       = 50
	listHeightOffset = 2
)

// Color scheme
var (
	primaryColor   = lipgloss.Color("205")
	secondaryColor = lipgloss.Color("240")
	successColor   = lipgloss.Color("42")
	subtleColor    = lipgloss.Color("241")
	borderColor    = lipgloss.Color("236")
	errorColor     = lipgloss.Color("196")
)

// UI style definitions grouped by purpose
var (
	// Text styles
	titleStyle = lipgloss.NewStyle().
			Bold(true).
			Foreground(primaryColor).
			MarginBottom(1)

	labelStyle = lipgloss.NewStyle().
			Foreground(secondaryColor).
			MarginRight(1)

	helpTextStyle = lipgloss.NewStyle().
			Foreground(subtleColor).
			Italic(true).
			MarginTop(1)

	loadingStyle = lipgloss.NewStyle().
			Foreground(primaryColor).
			Margin(1, 0)

	errorStyle = lipgloss.NewStyle().
			Foreground(errorColor).
			Bold(true)

	// Container styles

	containerStyle = lipgloss.NewStyle().
			Border(lipgloss.RoundedBorder()).
			BorderForeground(borderColor).
			Background(lipgloss.NoColor{}).
			Padding(1, 2).
			Margin(1, 0)

	// Checkbox styles
	checkboxStyle = lipgloss.NewStyle().
			Foreground(primaryColor).
			MarginRight(1)

	checkboxCheckedStyle = lipgloss.NewStyle().
				Foreground(successColor).
				MarginRight(1)

	// Status styles
	statusConnectedStyle = lipgloss.NewStyle().
				Foreground(successColor).
				Bold(true)

	statusDisconnectedStyle = lipgloss.NewStyle().
				Foreground(subtleColor)
)

// listKeyMap defines custom key bindings for the list view.
type listKeyMap struct {
	connect    key.Binding
	disconnect key.Binding
	disconnAll key.Binding
	refresh    key.Binding
}

var customKeys = listKeyMap{
	connect: key.NewBinding(
		key.WithKeys("enter"),
		key.WithHelp("enter", "connect"),
	),
	disconnect: key.NewBinding(
		key.WithKeys("d"),
		key.WithHelp("d", "disconnect"),
	),
	disconnAll: key.NewBinding(
		key.WithKeys("ctrl+x"),
		key.WithHelp("ctrl+x", "disconnect all"),
	),
	refresh: key.NewBinding(
		key.WithKeys("r"),
		key.WithHelp("r", "refresh"),
	),
}

// item represents a connection item in the list view.
type item struct {
	name      string
	address   string
	connected bool
	connType  string
}

// Title returns the display title for the item, with a bullet indicator if connected.
func (i item) Title() string {
	if i.connected {
		return "● " + i.name
	}
	return i.name
}

// Description returns the formatted description showing the address and connection status.
func (i item) Description() string {
	addressStyle := statusDisconnectedStyle
	prefix := ""
	if i.connType != "" {
		prefix = "[" + i.connType + "] "
	}
	if i.connected {
		addressStyle = statusConnectedStyle
		return addressStyle.Render(prefix+i.address) + " " + statusConnectedStyle.Render("• Connected")
	}
	return addressStyle.Render(prefix + i.address)
}

// FilterValue returns the value used for filtering items in the list.
func (i item) FilterValue() string { return i.name }

// customDelegate provides custom rendering for list items with connection status styling.
type customDelegate struct {
	list.DefaultDelegate
}

// Render renders a list item with custom styling based on selection and connection status.
func (d customDelegate) Render(w io.Writer, m list.Model, index int, listItem list.Item) {
	itm, ok := listItem.(item)
	if !ok {
		d.DefaultDelegate.Render(w, m, index, listItem)
		return
	}

	isSelected := index == m.Index()
	titleStyle := d.getTitleStyle(isSelected, itm.connected)
	title := titleStyle.Render(itm.Title())

	descStyle := d.Styles.NormalDesc
	if isSelected {
		descStyle = d.Styles.SelectedDesc
	}
	desc := descStyle.Render(itm.Description())

	fmt.Fprint(w, lipgloss.JoinVertical(lipgloss.Left, title, desc))
}

// getTitleStyle returns the appropriate title style based on selection and connection status.
func (d customDelegate) getTitleStyle(isSelected, isConnected bool) lipgloss.Style {
	baseStyle := lipgloss.NewStyle().
		Background(lipgloss.NoColor{}).
		Padding(0, 0, 0, 1)

	if isSelected {
		selectedStyle := d.Styles.SelectedTitle.
			Border(lipgloss.NormalBorder(), false, false, false, true).
			BorderForeground(primaryColor).
			Bold(true).
			Background(lipgloss.NoColor{}).
			Padding(0, 0, 0, 1)

		if isConnected {
			return selectedStyle.Foreground(successColor)
		}
		return selectedStyle.Foreground(primaryColor)
	}

	// Normal (unselected) item
	if isConnected {
		return baseStyle.
			Foreground(successColor).
			Bold(true)
	}
	return baseStyle.Foreground(lipgloss.Color("252"))
}

// newList creates and configures a new list model with custom styling.
func newList(items []list.Item, width, height int) list.Model {
	delegate := customDelegate{DefaultDelegate: list.NewDefaultDelegate()}
	delegate.Styles.SelectedTitle = delegate.Styles.SelectedTitle.
		Border(lipgloss.NormalBorder(), false, false, false, true).
		BorderForeground(primaryColor).
		Foreground(primaryColor).
		Bold(true).
		Background(lipgloss.NoColor{}).
		Padding(0, 0, 0, 1)
	delegate.Styles.SelectedDesc = delegate.Styles.SelectedDesc.
		Border(lipgloss.NormalBorder(), false, false, false, true).
		BorderForeground(primaryColor).
		Foreground(secondaryColor).
		Background(lipgloss.NoColor{}).
		Padding(0, 0, 0, 1)
	delegate.Styles.NormalDesc = delegate.Styles.NormalDesc.
		Foreground(subtleColor).
		Background(lipgloss.NoColor{}).
		Padding(0, 0, 0, 1)

	l := list.New(items, delegate, width, height)
	l.Title = ""
	l.SetShowStatusBar(false)
	l.SetShowPagination(false)
	l.SetFilteringEnabled(true)
	l.SetShowHelp(true)
	l.AdditionalShortHelpKeys = func() []key.Binding {
		return []key.Binding{
			customKeys.connect,
			customKeys.disconnect,
			customKeys.disconnAll,
			customKeys.refresh,
		}
	}
	l.Styles.StatusBar = lipgloss.NewStyle().
		Foreground(subtleColor).
		Background(lipgloss.NoColor{}).
		MarginTop(1)
	l.Styles.Title = lipgloss.NewStyle().
		Background(lipgloss.NoColor{})
	l.Styles.FilterPrompt = lipgloss.NewStyle().
		Background(lipgloss.NoColor{})
	l.Styles.FilterCursor = lipgloss.NewStyle().
		Background(lipgloss.NoColor{})
	return l
}

// isQuitKey checks if the given key string represents a quit command.
func isQuitKey(key string) bool {
	return key == "q" || key == "ctrl+c" || key == "esc"
}

// renderEmailPrompt renders the email authentication prompt view.
func renderEmailPrompt(m model) string {
	if m.loggingIn {
		title := titleStyle.Render("Authenticating...")
		spinnerText := loadingStyle.Render(m.spinner.View() + " Opening browser for authentication...")
		content := lipgloss.JoinVertical(lipgloss.Center,
			"",
			title,
			"",
			spinnerText,
			"",
		)

		width := clampWidth(m.width, minLoadingWidth, maxLoadingWidth)
		return lipgloss.Place(m.width, m.height, lipgloss.Center, lipgloss.Center,
			containerStyle.Width(width).Align(lipgloss.Center).Render(content))
	}

	checkbox := checkboxStyle.Render("[ ]")
	if m.rememberEmail {
		checkbox = checkboxCheckedStyle.Render("[x]")
	}

	title := titleStyle.Render("Authentication Required")
	message := labelStyle.Render("You are not authenticated. Please login.")
	emailLabel := labelStyle.Render("Email:")
	emailInput := m.emailInput.View()
	rememberText := checkbox + labelStyle.Render("Remember email (press Space to toggle)")
	helpText := helpTextStyle.Render("Press Enter to login, Esc to quit")

	content := lipgloss.JoinVertical(lipgloss.Left,
		title,
		"",
		message,
		"",
		emailLabel+emailInput,
		"",
		rememberText,
		"",
		helpText,
	)

	width := clampWidth(m.width, minEmailWidth, maxEmailWidth)
	return lipgloss.Place(m.width, m.height, lipgloss.Center, lipgloss.Center,
		containerStyle.Width(width).Render(content))
}

// renderLoading renders the loading spinner view.
func renderLoading(m model) string {
	title := titleStyle.Render("Loading Connections")
	spinnerText := loadingStyle.Render(m.spinner.View() + " Loading connections...")
	content := lipgloss.JoinVertical(lipgloss.Center,
		"",
		title,
		"",
		spinnerText,
		"",
	)

	width := clampWidth(m.width, minLoadingWidth, maxLoadingWidth)
	return lipgloss.Place(m.width, m.height, lipgloss.Center, lipgloss.Center,
		containerStyle.Width(width).Align(lipgloss.Center).Render(content))
}

// renderError renders the error view with retry and quit options.
func renderError(m model) string {
	title := titleStyle.Render("Error")
	errText := errorStyle.Render(m.err)
	helpText := helpTextStyle.Render("Press r to retry, q/Esc to quit")
	content := lipgloss.JoinVertical(lipgloss.Center,
		"",
		title,
		"",
		errText,
		"",
		helpText,
		"",
	)

	width := clampWidth(m.width, minLoadingWidth, maxLoadingWidth)
	return lipgloss.Place(m.width, m.height, lipgloss.Center, lipgloss.Center,
		containerStyle.Width(width).Align(lipgloss.Center).Render(content))
}

// clampWidth constrains the width value between min and max.
func clampWidth(width, min, max int) int {
	if width > max {
		return max
	}
	if width < min {
		return min
	}
	return width
}