(function () {
    "use strict";

    var themes = ["indigo", "dark", "light", "ocean", "forest"];
    var icons = {
        indigo: "bi-moon-stars",
        dark: "bi-circle-half",
        light: "bi-sun",
        ocean: "bi-water",
        forest: "bi-tree"
    };
    var lightThemes = { light: true, ocean: true };
    var btn = document.getElementById("theme-toggle");
    var current = localStorage.getItem("ws-theme") || "indigo";

    function apply(theme) {
        document.documentElement.setAttribute("data-theme", theme);
        document.documentElement.setAttribute(
            "data-bs-theme",
            lightThemes[theme] ? "light" : "dark"
        );
        btn.querySelector("i").className = "bi " + icons[theme];
        btn.title = theme.charAt(0).toUpperCase() + theme.slice(1) + " theme";
        localStorage.setItem("ws-theme", theme);
        current = theme;
    }

    apply(current);

    btn.addEventListener("click", function () {
        var idx = (themes.indexOf(current) + 1) % themes.length;
        apply(themes[idx]);
    });
})();