let langs = {
    en : {
        // error message in case the survey url was obviously invalid (currently only the case if none was given)
        "Error: nothing here": "There's nothing here. Maybe try appending something after the url?\n\nAlternatively, check to see if you copied the whole url.",
        // error message in case the http request on the survey url returned a status code that wasn't 200
        "Error: survey doesn't exist": "Could not load this survey; are you sure that it exists?",
        // error message in case the survey url was loaded, but had some obviously invalid format (i.e. neither json nor age encryption)
        "Error: unknown format": "Could not load this survey; it appears to be in a wrong or unknown format.",
        // text fragment in error messages, after which the survey url will be printed
        "attempted path:": "Attempted path:",
        // prompt for a passphrase
        "please enter passphrase": "please enter a passphrase to access the survey:",
        // error message in case decryption failed
        "passphrase incorrect": "passphrase was incorrect!",
        // document title for the decryption dialog
        "Enter Passphrase": "Enter Passphrase",
        // header of the decryption dialog
        "Passphrase": "Passphrase",
        // the text on the "decrypt" button
        "decrypt": "decrypt",
        // the text on the "submit" button
        "submit": "submit",
        // error message in case the given answers were invalid
        "Error: answers invalid":"Cannot submit: not all required questions were filled in!",
        // error message in case the post request failed entirely (i.e. printed if the .catch-clause of the fetch() function is reached)
        "Error: could not post":"Error: The http POST request did not succeed.",
        // error message in case the post request returned some other status code than 200; its status code and message will be appended in the next line after the text given here
        "Error: post returned error":"Error: The http POST request returned an error code:"
    },
    de : {
        "Error: nothing here": "Hier ist nichts. Evtl. hilft es, etwas hinten an die url dranzuhängen?\n\nAnsonsten: bist du dir sicher, dass du den ganzen Link hierher kopiert hast?",
        "Error: survey doesn't exist": "Diese Umfrage konnte nicht geladen werden. Bist du sicher, dass sie existiert?",
        "Error: unknown format": "Diese Umfrage scheint ein unbekanntes Format zu haben und konnte nicht angezeigt werden",
        "attempted path:": "Abgerufener Pfad:",
        "please enter passphrase": "Bitte gebe eine Passphrase ein, um die Umfrage zu entschlüsseln",
        "passphrase incorrect": "Passphrase war nicht korrekt!",
        "Passphrase": "Passphrase",
        "decrypt":"entschlüsseln",
        "submit":"absenden",
        "Enter Passphrase": "Passphrase eingeben",
        "Error: answers invalid":"Einige verpflichtenden Antworten fehlen!",
        "Error: could not post":"Fehler: Die http POST Anfrage schlug fehl.",
        "Error: post returned error":"Fehler: Die http POST Anfragen schlug fehl und gab einen Fehlercode zurück:"
    }
}

// we use english by default until something else is set
let locale = "en";

// the main translation function. if no fitting translation
// is found, it returns the key as a fallback value
// (therefore, keys should themselves be understandable texts)
export function _(key) {
    return !(locale in langs) ? key
        : !(key in langs[locale]) ? key
        : langs[locale][key]
}

export function setLang (loc) {
    locale = loc;
}

/// attempt to set the site's language to the browser's preference.
/// in case it's not supported it tries any of the languages in
/// navigator.languages, and then falls back to english.
export function tryBrowserDefaultLang () {
    let guess = navigator.language;
    if (guess in langs) {
        setLang(lang);
    } else {
        for (var lang of navigator.languages) {
            if (lang in langs) {
                setLang (lang);
                return;
            }
        }
        setLang("en");
    }
}

export default _;