package middleware

import (
	"context"
	"net/http"
	"os"

	c "github.com/juanatsap/cv-site/internal/constants"
)

// contextKey is a private type for context keys to avoid collisions
type contextKey string

const (
	// PreferencesKey is the context key for user preferences
	PreferencesKey contextKey = "preferences"
)

// Preferences holds user preference values from cookies
type Preferences struct {
	CVLength    string // "short" or "long"
	CVIcons     string // "show" or "hide"
	CVLanguage  string // "en" or "es"
	CVTheme     string // "default" or "clean"
	ColorTheme  string // "light" or "dark"
}

// PreferencesMiddleware reads user preferences from cookies and stores them in context
// This eliminates the need for handlers to manually read cookies
func PreferencesMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		prefs := &Preferences{
			CVLength:   getPreferenceCookie(r, c.CookieCVLength, c.CVLengthShort),
			CVIcons:    getPreferenceCookie(r, c.CookieCVIcons, c.CVIconsShow),
			CVLanguage: getPreferenceCookie(r, c.CookieCVLanguage, c.LangEnglish),
			CVTheme:    getPreferenceCookie(r, c.CookieCVTheme, c.CVThemeDefault),
			ColorTheme: getPreferenceCookie(r, c.CookieColorTheme, c.ColorThemeLight),
		}

		// Migrate old preference values (one-time auto-migration)
		if prefs.CVLength == "extended" {
			prefs.CVLength = c.CVLengthLong
		}
		switch prefs.CVIcons {
		case "true":
			prefs.CVIcons = c.CVIconsShow
		case "false":
			prefs.CVIcons = c.CVIconsHide
		}

		// Store preferences in context
		ctx := context.WithValue(r.Context(), PreferencesKey, prefs)
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

// GetPreferences retrieves preferences from request context
func GetPreferences(r *http.Request) *Preferences {
	prefs, ok := r.Context().Value(PreferencesKey).(*Preferences)
	if !ok {
		// Return default preferences if not found
		return &Preferences{
			CVLength:   c.CVLengthShort,
			CVIcons:    c.CVIconsShow,
			CVLanguage: c.LangEnglish,
			CVTheme:    c.CVThemeDefault,
			ColorTheme: c.ColorThemeLight,
		}
	}
	return prefs
}

// ==============================================================================
// CONTEXT HELPER FUNCTIONS
// Convenience functions for accessing specific preference values
// ==============================================================================

// GetLanguage retrieves the user's language preference
func GetLanguage(r *http.Request) string {
	return GetPreferences(r).CVLanguage
}

// GetCVLength retrieves the user's CV length preference
func GetCVLength(r *http.Request) string {
	return GetPreferences(r).CVLength
}

// GetCVIcons retrieves the user's icon visibility preference
func GetCVIcons(r *http.Request) string {
	return GetPreferences(r).CVIcons
}

// GetCVTheme retrieves the user's CV theme preference
func GetCVTheme(r *http.Request) string {
	return GetPreferences(r).CVTheme
}

// GetColorTheme retrieves the user's color theme preference
func GetColorTheme(r *http.Request) string {
	return GetPreferences(r).ColorTheme
}

// IsLongCV returns true if the user prefers long CV format
func IsLongCV(r *http.Request) bool {
	return GetCVLength(r) == c.CVLengthLong
}

// IsShortCV returns true if the user prefers short CV format
func IsShortCV(r *http.Request) bool {
	return GetCVLength(r) == c.CVLengthShort
}

// ShowIcons returns true if icons should be visible
func ShowIcons(r *http.Request) bool {
	return GetCVIcons(r) == c.CVIconsShow
}

// HideIcons returns true if icons should be hidden
func HideIcons(r *http.Request) bool {
	return GetCVIcons(r) == c.CVIconsHide
}

// IsCleanTheme returns true if clean theme is selected
func IsCleanTheme(r *http.Request) bool {
	return GetCVTheme(r) == c.CVThemeClean
}

// IsDefaultTheme returns true if default theme is selected
func IsDefaultTheme(r *http.Request) bool {
	return GetCVTheme(r) == c.CVThemeDefault
}

// IsDarkMode returns true if dark mode is enabled
func IsDarkMode(r *http.Request) bool {
	return GetColorTheme(r) == c.ColorThemeDark
}

// IsLightMode returns true if light mode is enabled
func IsLightMode(r *http.Request) bool {
	return GetColorTheme(r) == c.ColorThemeLight
}

// SetPreferenceCookie sets a preference cookie (1 year expiry)
func SetPreferenceCookie(w http.ResponseWriter, name string, value string) {
	http.SetCookie(w, &http.Cookie{
		Name:     name,
		Value:    value,
		Path:     c.CookiePath,
		MaxAge:   c.CookieMaxAge,
		HttpOnly: true,
		SameSite: http.SameSiteStrictMode,
		Secure:   isProductionMode(), // Secure in production with HTTPS
	})
}

// isProductionMode checks if the application is running in production
func isProductionMode() bool {
	env := os.Getenv(c.EnvVarGOEnv)
	return env == c.EnvProduction || env == "prod"
}

// getPreferenceCookie gets a preference cookie value, returns default if not found
func getPreferenceCookie(r *http.Request, name string, defaultValue string) string {
	cookie, err := r.Cookie(name)
	if err != nil {
		return defaultValue
	}
	return cookie.Value
}