/*!
 * SAPUI5
 * Copyright (c) 2025 SAP SE or an SAP affiliate company. All rights reserved.
 */
declare global {
    interface Document {
        documentMode: string;
    }
}

declare global {
    interface Navigator {
        browserLanguage: string;
    }
}

declare global {
    interface Window {
        chrome: { webstore?: unknown };
        InstallTrigger: unknown;
        StyleMedia: unknown;
    }
}

export function getLanguagePreferences(): Array<LanguagePreference> {
    const isFirefox = typeof window.InstallTrigger !== "undefined";
    // eslint-disable-next-line no-constant-binary-expression
    const isIE = false || !!document.documentMode;
    const isEdge = !isIE && !!window.StyleMedia;
    const isChrome = !!window.chrome && !!window.chrome.webstore;
    const languagePreferences = [];
    if (isIE || isEdge) {
        const ieLang = window.navigator.browserLanguage || window.navigator.language;
        languagePreferences.splice(0, 0, this._getLanguageCountryObject(ieLang));
    } else if (isFirefox || isChrome) {
        const language = window.navigator.language;
        const languages = window.navigator.languages.slice();
        const index = languages.indexOf(language);
        if (index > -1) {
            languages.splice(index, 1);
        }
        languagePreferences.splice(0, 0, this._getLanguageCountryObject(language));
        for (let i = 0; i < languages.length; i++) {
            const languagePreference = this._getLanguageCountryObject(languages[i]);
            if (languagePreference) {
                languagePreferences.splice(languagePreferences.length, 0, languagePreference);
            }
        }
    } else {
        languagePreferences.splice(0, 0, this._getLanguageCountryObject(window.navigator.language));
    }
    return languagePreferences;
}

export interface LanguagePreference {
    Language: string;
    Country: string;
}

export function _getLanguageCountryObject(l: string): LanguagePreference {
    let language: string;
    let country: string;
    if (l.length === 2) {
        language = l;
        country = "";
    } else if (l.length === 5 && l.indexOf("-") === 2) {
        language = l.substr(0, 2);
        country = l.substr(3);
    } else {
        return undefined;
    }
    return { Language: language, Country: country };
}