/**
 * Bundle-size gate for CI.
 *
 * Finds all .js files in dist/remote/static/js/, measures their gzip size,
 * reports per-file and total, and fails if total exceeds the budget.
 *
 * Budgets:
 *   - Total remote bundle: <= 2000 kB gzip
 */

import { readFileSync, readdirSync, statSync } from "node:fs";
import { join } from "node:path";
import { gzipSync } from "node:zlib";

const BUDGET_TOTAL_KB = 2000;
const JS_DIR = "dist/remote/static/js";

function collectJsFiles(dir) {
  const results = [];
  let entries;
  try {
    entries = readdirSync(dir);
  } catch {
    return results;
  }
  for (const entry of entries) {
    const full = join(dir, entry);
    const stat = statSync(full, { throwIfNoEntry: false });
    if (!stat) continue;
    if (stat.isDirectory()) {
      results.push(...collectJsFiles(full));
    } else if (entry.endsWith(".js")) {
      results.push(full);
    }
  }
  return results;
}

const files = collectJsFiles(JS_DIR);

if (files.length === 0) {
  console.error(`No .js files found in ${JS_DIR}. Did the build run?`);
  process.exit(1);
}

let totalGzip = 0;
const rows = [];

for (const file of files) {
  const raw = readFileSync(file);
  const gzipped = gzipSync(raw);
  const gzipKB = gzipped.length / 1024;
  totalGzip += gzipKB;
  rows.push({ file: file.replace("dist/remote/", ""), rawKB: (raw.length / 1024).toFixed(1), gzipKB: gzipKB.toFixed(1) });
}

rows.sort((a, b) => parseFloat(b.gzipKB) - parseFloat(a.gzipKB));

console.log("\n--- Bundle Size Report ---\n");
console.log(
  "File".padEnd(60) +
  "Raw (kB)".padStart(12) +
  "Gzip (kB)".padStart(12)
);
console.log("-".repeat(84));

for (const r of rows) {
  console.log(
    r.file.padEnd(60) +
    r.rawKB.padStart(12) +
    r.gzipKB.padStart(12)
  );
}

console.log("-".repeat(84));
console.log(
  "TOTAL".padEnd(60) +
  "".padStart(12) +
  totalGzip.toFixed(1).padStart(12)
);
console.log(`\nBudget: ${BUDGET_TOTAL_KB} kB gzip`);

if (totalGzip > BUDGET_TOTAL_KB) {
  console.error(`\nFAILED: Total gzip size ${totalGzip.toFixed(1)} kB exceeds budget of ${BUDGET_TOTAL_KB} kB`);
  process.exit(1);
} else {
  console.log(`\nPASSED: ${totalGzip.toFixed(1)} kB / ${BUDGET_TOTAL_KB} kB budget`);
}