#lang racket/base

(require racket/string)

(provide tr
         __
         languages
         set-lang!
         current-lang)

(define translation-map
  (hasheq
   'en
   (hasheq
    'app-title "RKT Web Player Agent"
    'server "RKT Web Player server"
    'name "Name"
    'application-id "Application ID"
    'playback "Playback"
    'no-track "Nothing is playing"
    'no-track-selected "No track selected"
    'save-connect "Save and connect"
    'reconnect "Reconnect"
    'connecting "Connecting…"
    'connected "Connected"
    'denied-title "Playback agent not allowed"
    'denied-message "This playback agent is not allowed by the server. Add the following application ID to [playback-agents] in the server INI:\n\n~a"
    'unauthorized-status "Not authorized — application ID is not in the server INI"
    'disconnected "Not connected: ~a"
    'playing "Playing"
    'paused "Paused"
    'loading "Loading"
    'stopped "Stopped"
    'channel "channel"
    'channels "channels"
    'tray-open "Open RKT Web Player Agent"
    'quit "Quit")
   'nl
   (hasheq
    'app-title "RKT Web Player Agent"
    'server "RKT Web Player server"
    'name "Naam"
    'application-id "Applicatie-ID"
    'playback "Afspelen"
    'no-track "Er wordt niets afgespeeld"
    'no-track-selected "Geen track geselecteerd"
    'save-connect "Opslaan en verbinden"
    'reconnect "Opnieuw verbinden"
    'connecting "Verbinden…"
    'connected "Verbonden"
    'denied-title "Playback agent niet toegestaan"
    'denied-message "Deze playback agent is niet toegelaten door de server. Voeg het volgende applicatie-ID toe aan [playback-agents] in de server-INI:\n\n~a"
    'unauthorized-status "Niet geautoriseerd — applicatie-ID staat niet in de server-INI"
    'disconnected "Niet verbonden: ~a"
    'playing "Speelt"
    'paused "Gepauzeerd"
    'loading "Laden"
    'stopped "Gestopt"
    'channel "kanaal"
    'channels "kanalen"
    'tray-open "RKT Web Player Agent openen"
    'quit "Afsluiten")
   'de
   (hasheq
    'app-title "RKT Web Player Agent"
    'server "RKT Web Player Server"
    'name "Name"
    'application-id "Anwendungs-ID"
    'playback "Wiedergabe"
    'no-track "Keine Wiedergabe"
    'no-track-selected "Kein Titel ausgewählt"
    'save-connect "Speichern und verbinden"
    'reconnect "Neu verbinden"
    'connecting "Verbinden…"
    'connected "Verbunden"
    'denied-title "Playback-Agent nicht zugelassen"
    'denied-message "Dieser Playback-Agent ist vom Server nicht zugelassen. Fügen Sie die folgende Anwendungs-ID unter [playback-agents] in die Server-INI ein:\n\n~a"
    'unauthorized-status "Nicht autorisiert — Anwendungs-ID fehlt in der Server-INI"
    'disconnected "Nicht verbunden: ~a"
    'playing "Wiedergabe"
    'paused "Pausiert"
    'loading "Laden"
    'stopped "Gestoppt"
    'channel "Kanal"
    'channels "Kanäle"
    'tray-open "RKT Web Player Agent öffnen"
    'quit "Beenden")
   'fr
   (hasheq
    'app-title "Agent RKT Web Player"
    'server "Serveur RKT Web Player"
    'name "Nom"
    'application-id "ID d’application"
    'playback "Lecture"
    'no-track "Aucune lecture en cours"
    'no-track-selected "Aucune piste sélectionnée"
    'save-connect "Enregistrer et connecter"
    'reconnect "Reconnecter"
    'connecting "Connexion…"
    'connected "Connecté"
    'denied-title "Agent de lecture non autorisé"
    'denied-message "Cet agent de lecture n’est pas autorisé par le serveur. Ajoutez l’ID d’application suivant à [playback-agents] dans le fichier INI du serveur :\n\n~a"
    'unauthorized-status "Non autorisé — l’ID d’application est absent du fichier INI du serveur"
    'disconnected "Non connecté : ~a"
    'playing "Lecture"
    'paused "En pause"
    'loading "Chargement"
    'stopped "Arrêté"
    'channel "canal"
    'channels "canaux"
    'tray-open "Ouvrir l’agent RKT Web Player"
    'quit "Quitter")
   'es
   (hasheq
    'app-title "Agente de RKT Web Player"
    'server "Servidor RKT Web Player"
    'name "Nombre"
    'application-id "ID de aplicación"
    'playback "Reproducción"
    'no-track "No se está reproduciendo nada"
    'no-track-selected "No hay ninguna pista seleccionada"
    'save-connect "Guardar y conectar"
    'reconnect "Volver a conectar"
    'connecting "Conectando…"
    'connected "Conectado"
    'denied-title "Agente de reproducción no permitido"
    'denied-message "El servidor no permite este agente de reproducción. Añade el siguiente ID de aplicación a [playback-agents] en el INI del servidor:\n\n~a"
    'unauthorized-status "No autorizado — el ID de aplicación no está en el INI del servidor"
    'disconnected "Sin conexión: ~a"
    'playing "Reproduciendo"
    'paused "En pausa"
    'loading "Cargando"
    'stopped "Detenido"
    'channel "canal"
    'channels "canales"
    'tray-open "Abrir el agente de RKT Web Player"
    'quit "Salir")))

(define (system-language)
  (define language-name
    (string-downcase (format "~a" (system-language+country))))
  (define short-name (car (regexp-split #px"[-_]" language-name)))
  (define candidate (string->symbol short-name))
  (if (hash-has-key? translation-map candidate) candidate 'en))

(define language (system-language))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; goal   : Return the supported language symbols and their native names.
; pre    : None.
; post   : Translation state remains unchanged.
; result : An association list suitable for a language selector.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (languages)
  '((en "English")
    (nl "Nederlands")
    (de "Deutsch")
    (fr "Français")
    (es "Español")))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; goal   : Select the language used by tr and __.
; pre    : Value is one of the symbols returned by languages.
; post   : Subsequent translations use value.
; result : Void.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (set-lang! value)
  (unless (hash-has-key? translation-map value)
    (raise-argument-error 'set-lang! "supported language symbol" value))
  (set! language value))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; goal   : Report the active translation language.
; pre    : None.
; post   : Translation state remains unchanged.
; result : A supported language symbol.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (current-lang)
  language)

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; goal   : Translate an application string identifier.
; pre    : Id is a symbol.
; post   : Translation state remains unchanged.
; result : The active translation, its English fallback, or the identifier.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (tr id)
  (hash-ref (hash-ref translation-map language)
            id
            (λ ()
              (hash-ref (hash-ref translation-map 'en)
                        id
                        (λ () (symbol->string id))))))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; goal   : Provide the conventional short alias used by rktplayer GUI code.
; pre    : Id is a symbol.
; post   : Translation state remains unchanged.
; result : The same translated string as tr.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define (__ id)
  (tr id))

(module+ test
  (require rackunit)

  (define original-language (current-lang))
  (dynamic-wind
    void
    (λ ()
      (set-lang! 'nl)
      (check-equal? (tr 'connected) "Verbonden")
      (set-lang! 'de)
      (check-equal? (__ 'quit) "Beenden")
      (check-equal? (tr 'unknown-translation) "unknown-translation")
      (check-exn exn:fail:contract? (λ () (set-lang! 'xx))))
    (λ () (set-lang! original-language))))