// CSS 健康度审计脚本。
// 用法: npm run css:audit
// 输出每个 CSS 文件的行数、选择器数、!important 数、@media 数，
// 以及 !important 密度（每 100 行的 !important 数）。
// 用于建立基线、跟踪 CSS 瘦身进度、防止 !important 回潮。

import { readFileSync, readdirSync, statSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname, join, relative } from "node:path";

const ROOT = join(dirname(fileURLToPath(import.meta.url)), "..", "src", "styles");
const REPORT = [];

function scanCssFile(filePath) {
  const content = readFileSync(filePath, "utf-8");
  const lines = content.split(/\r?\n/).length;
  const selectors = (content.match(/\{/g) || []).length;
  const important = (content.match(/!important/g) || []).length;
  const media = (content.match(/@media/g) || []).length;
  const density = lines > 0 ? ((important / lines) * 100).toFixed(1) : "0";
  return { lines, selectors, important, media, density };
}

function walk(dir) {
  for (const entry of readdirSync(dir)) {
    const full = join(dir, entry);
    const st = statSync(full);
    if (st.isDirectory()) {
      walk(full);
    } else if (entry.endsWith(".css")) {
      const rel = relative(ROOT, full).replace(/\\/g, "/");
      REPORT.push({ file: rel, ...scanCssFile(full) });
    }
  }
}

walk(ROOT);

// Sort by !important count descending to surface the worst offenders.
REPORT.sort((a, b) => b.important - a.important);

const totals = REPORT.reduce(
  (acc, r) => {
    acc.lines += r.lines;
    acc.selectors += r.selectors;
    acc.important += r.important;
    acc.media += r.media;
    return acc;
  },
  { lines: 0, selectors: 0, important: 0, media: 0 },
);

const pad = (s, n) => String(s).padEnd(n);
const num = (s, n) => String(s).padStart(n);

console.log("\nCSS Audit Report — src/styles/\n");
console.log(
  `${pad("File", 52)} ${num("Lines", 7)} ${num("Sel", 6)} ${num("!imp", 7)} ${num("@media", 7)}  imp/100ln`,
);
console.log("-".repeat(92));
for (const r of REPORT) {
  console.log(
    `${pad(r.file, 52)} ${num(r.lines, 7)} ${num(r.selectors, 6)} ${num(r.important, 7)} ${num(r.media, 7)}  ${r.density}`,
  );
}
console.log("-".repeat(92));
console.log(
  `${pad("TOTAL", 52)} ${num(totals.lines, 7)} ${num(totals.selectors, 6)} ${num(totals.important, 7)} ${num(totals.media, 7)}  ${((totals.important / totals.lines) * 100).toFixed(1)}`,
);
console.log("");

// Exit non-zero if total !important exceeds a budget threshold.
// Post-@layer refactoring baseline: ~970 (formerly ~7812).
// Budget set to 2000 to prevent regression while allowing controlled growth.
const IMPORTANT_BUDGET = 2000;
if (totals.important > IMPORTANT_BUDGET) {
  console.error(
    `FAIL: !important count ${totals.important} exceeds budget ${IMPORTANT_BUDGET}. ` +
      `Run with --no-important-check to bypass (not recommended).`,
  );
  process.exit(1);
} else {
  console.log(
    `OK: !important count ${totals.important} within budget ${IMPORTANT_BUDGET} ` +
      `(headroom ${IMPORTANT_BUDGET - totals.important}).`,
  );
}