wg-admin/internal/tui/theme/theme.go

package theme

import (
	"fmt"
	"os"
	"sync"

	"github.com/charmbracelet/lipgloss"
)

// ColorScheme defines the color palette for the theme
type ColorScheme struct {
	Primary    lipgloss.Color
	Success    lipgloss.Color
	Warning    lipgloss.Color
	Error      lipgloss.Color
	Muted      lipgloss.Color
	Background lipgloss.Color
}

// Theme represents a color theme with its name and color scheme
type Theme struct {
	Name   string
	Scheme ColorScheme
}

// Global variables for current theme and styles
var (
	currentTheme *Theme
	once         sync.Once

	// Global styles that can be used throughout the application
	StylePrimary       lipgloss.Style
	StyleSuccess       lipgloss.Style
	StyleWarning       lipgloss.Style
	StyleError         lipgloss.Style
	StyleMuted         lipgloss.Style
	StyleTitle         lipgloss.Style
	StyleSubtitle      lipgloss.Style
	StyleHelpKey       lipgloss.Style
	StyleValue         lipgloss.Style
	StyleDimmed        lipgloss.Style
	StyleTableHeader   lipgloss.Style
	StyleTableSelected lipgloss.Style
	StyleBorder        lipgloss.Color
	StyleBackground    lipgloss.Color
)

// DefaultTheme is the standard blue-based theme
var DefaultTheme = &Theme{
	Name: "default",
	Scheme: ColorScheme{
		Primary:    lipgloss.Color("62"),  // Blue
		Success:    lipgloss.Color("46"),  // Green
		Warning:    lipgloss.Color("208"), // Orange
		Error:      lipgloss.Color("196"), // Red
		Muted:      lipgloss.Color("241"), // Gray
		Background: lipgloss.Color(""),    // Default terminal background
	},
}

// DarkTheme is a purple-based dark theme
var DarkTheme = &Theme{
	Name: "dark",
	Scheme: ColorScheme{
		Primary:    lipgloss.Color("141"), // Purple
		Success:    lipgloss.Color("51"),  // Cyan
		Warning:    lipgloss.Color("226"), // Yellow
		Error:      lipgloss.Color("196"), // Red
		Muted:      lipgloss.Color("245"), // Light gray
		Background: lipgloss.Color(""),    // Default terminal background
	},
}

// LightTheme is a green-based light theme
var LightTheme = &Theme{
	Name: "light",
	Scheme: ColorScheme{
		Primary:    lipgloss.Color("34"),  // Green
		Success:    lipgloss.Color("36"),  // Teal
		Warning:    lipgloss.Color("214"), // Amber
		Error:      lipgloss.Color("196"), // Red
		Muted:      lipgloss.Color("244"), // Gray
		Background: lipgloss.Color(""),    // Default terminal background
	},
}

// DraculaTheme is the popular Dracula dark color scheme
var DraculaTheme = &Theme{
	Name: "dracula",
	Scheme: ColorScheme{
		Primary:    lipgloss.Color("#BD93F9"), // Purple
		Success:    lipgloss.Color("#50FA7B"), // Green
		Warning:    lipgloss.Color("#FFB86C"), // Orange
		Error:      lipgloss.Color("#FF5555"), // Red
		Muted:      lipgloss.Color("#6272A4"), // Light purple-gray
		Background: lipgloss.Color("#282A36"), // Dark background
	},
}

// EverforestTheme is the natural Everforest dark color scheme
var EverforestTheme = &Theme{
	Name: "everforest",
	Scheme: ColorScheme{
		Primary:    lipgloss.Color("#7fbbb3"), // Blue
		Success:    lipgloss.Color("#a7c080"), // Green
		Warning:    lipgloss.Color("#dbbc7f"), // Yellow
		Error:      lipgloss.Color("#e67e80"), // Red
		Muted:      lipgloss.Color("#414b50"), // Gray
		Background: lipgloss.Color("#272e33"), // Dark background
	},
}

// ThemeRegistry holds all available themes
var ThemeRegistry = map[string]*Theme{
	"default":    DefaultTheme,
	"dark":       DarkTheme,
	"light":      LightTheme,
	"dracula":    DraculaTheme,
	"everforest": EverforestTheme,
}

// GetTheme loads the theme from config or environment variable
// Returns the default theme if no theme is specified
func GetTheme() (*Theme, error) {
	once.Do(func() {
		// Try to get theme from environment variable first
		themeName := os.Getenv("THEME")
		if themeName == "" {
			themeName = "everforest"
		}

		// Look up the theme in the registry
		if theme, ok := ThemeRegistry[themeName]; ok {
			currentTheme = theme
		} else {
			// If theme not found, use everforest as default
			currentTheme = EverforestTheme
		}

		// Apply the theme to initialize styles
		ApplyTheme(currentTheme)
	})

	return currentTheme, nil
}

// ApplyTheme applies the given theme to all global styles
func ApplyTheme(theme *Theme) {
	currentTheme = theme

	// Primary style
	StylePrimary = lipgloss.NewStyle().
		Foreground(theme.Scheme.Primary)

	// Success style
	StyleSuccess = lipgloss.NewStyle().
		Foreground(theme.Scheme.Success)

	// Warning style
	StyleWarning = lipgloss.NewStyle().
		Foreground(theme.Scheme.Warning)

	// Error style
	StyleError = lipgloss.NewStyle().
		Foreground(theme.Scheme.Error)

	// Muted style
	StyleMuted = lipgloss.NewStyle().
		Foreground(theme.Scheme.Muted)

	// Title style (bold primary)
	StyleTitle = lipgloss.NewStyle().
		Foreground(theme.Scheme.Primary).
		Bold(true)

	// Subtitle style (muted)
	StyleSubtitle = lipgloss.NewStyle().
		Foreground(theme.Scheme.Muted)

	// Help key style (bold primary, slightly different shade)
	StyleHelpKey = lipgloss.NewStyle().
		Foreground(theme.Scheme.Primary).
		Bold(true)

	// Value style for content values
	StyleValue = lipgloss.NewStyle().
		Foreground(lipgloss.Color("255"))

	// Dimmed style for overlay content
	StyleDimmed = lipgloss.NewStyle().
		Foreground(theme.Scheme.Muted)

	// Table header style
	StyleTableHeader = lipgloss.NewStyle().
		BorderStyle(lipgloss.NormalBorder()).
		BorderForeground(lipgloss.Color("240")).
		BorderBottom(true).
		Bold(true)

	// Table selected style
	StyleTableSelected = lipgloss.NewStyle().
		Foreground(lipgloss.Color("229")).
		Background(lipgloss.Color("57")).
		Bold(false)

	// Border color
	StyleBorder = lipgloss.Color("240")

	// Background color for modals
	StyleBackground = lipgloss.Color("235")
}

// GetThemeNames returns a list of available theme names
func GetThemeNames() []string {
	names := make([]string, 0, len(ThemeRegistry))
	for name := range ThemeRegistry {
		names = append(names, name)
	}
	return names
}

// SetTheme changes the current theme by name
func SetTheme(name string) error {
	theme, ok := ThemeRegistry[name]
	if !ok {
		return fmt.Errorf("theme '%s' not found. Available themes: %v", name, GetThemeNames())
	}

	ApplyTheme(theme)
	return nil
}

// GetCurrentTheme returns the currently active theme
func GetCurrentTheme() *Theme {
	if currentTheme == nil {
		currentTheme = DefaultTheme
		ApplyTheme(currentTheme)
	}
	return currentTheme
}

// GetColorScheme returns the color scheme of the current theme
func GetColorScheme() ColorScheme {
	return GetCurrentTheme().Scheme
}