thi-ng/umbrella

import { isString } from "@thi.ng/checks/is-string";
import { expand, indent } from "./impl.js";
import type { Conditional, CSSOpts, RuleFn } from "./api.js";

export const conditional =
    (type: string, cond: Conditional, rules: any[]): RuleFn =>
    (acc: string[], opts: CSSOpts) => {
        const space = indent(opts);
        acc.push(`${space}${type} ${formatCond(cond)}${opts.format.declStart}`);
        opts.depth++;
        expand(acc, [], rules, opts);
        opts.depth--;
        acc.push(space + opts.format.declEnd);
        return acc;
    };

const formatCond = (cond: any) => {
    if (isString(cond)) {
        return cond;
    }
    const acc = [];
    for (let c in cond) {
        if (cond.hasOwnProperty(c)) {
            let v = cond[c];
            if (v === true) {
                v = MEDIA_TYPES.has(c) ? c : `(${c})`;
            } else if (v === false) {
                v = `(not ${MEDIA_TYPES.has(c) ? c : `(${c})`})`;
            } else if (v === "only") {
                v += " " + c;
            } else {
                v = `(${c}:${v})`;
            }
            acc.push(v);
        }
    }
    return acc.join(" and ");
};

const MEDIA_TYPES = new Set(["all", "print", "screen"]);