import assert from "node:assert/strict";
import { readFileSync } from "node:fs";

const globalStylesUrl = new URL("../src/app/globals.css", import.meta.url);

/**
 * Declaration text for every rule that targets `selector`.
 *
 * A selector is normally declared once at the base layer and again inside
 * media queries, so reading only the first occurrence reports whichever rule
 * happens to appear earliest in the file. That makes a positive assertion fail
 * when a responsive override is added above the base rule, and lets a negative
 * assertion pass while an override still declares the forbidden property.
 * Joining every matching rule keeps both directions honest.
 */
export function cssDeclarations(selector: string, source = readFileSync(globalStylesUrl, "utf8")) {
  // A comment sits between the previous rule and the selector it documents, so
  // it lands inside the captured selector text unless it is removed first.
  const withoutComments = source.replace(/\/\*[\s\S]*?\*\//g, " ");
  const normalize = (value: string) => value.trim().replace(/\s+/g, " ");
  // A caller may ask for a whole group, so any component counts as a hit.
  const wanted = selector.split(",").map(normalize).filter(Boolean);
  const bodies: string[] = [];
  for (const [, selectorList, body] of withoutComments.matchAll(/([^{}]+)\{([^{}]*)\}/g)) {
    const targets = selectorList.split(",").map(normalize);
    const hit = targets.some((target) => wanted.some(
      (value) => target === value || target.endsWith(` ${value}`),
    ));
    if (hit) bodies.push(body.trim());
  }
  assert.notEqual(bodies.length, 0, `missing CSS selector: ${selector}`);
  return bodies.join(" ");
}