/* Post-build: copy CSS + image assets into dist/, then fix ESM imports.
 *
 * tsc only emits .js + .d.ts. The CSS lives in src/styles/ alongside an
 * `index.css` that @imports the other sheets; we copy the whole tree
 * to dist/ so `@gsc/web-kit/css` resolves correctly.
 */

const fs = require("fs");
const path = require("path");

const root = path.join(__dirname, "..");
const distDir = path.join(root, "dist");
const srcStyles = path.join(root, "src", "styles");
const distStyles = path.join(distDir, "styles");

// 1. Mirror src/styles/ → dist/styles/ (CSS + images).
function copyDir(src, dst) {
  fs.mkdirSync(dst, { recursive: true });
  for (const entry of fs.readdirSync(src, { withFileTypes: true })) {
    const s = path.join(src, entry.name);
    const d = path.join(dst, entry.name);
    if (entry.isDirectory()) copyDir(s, d);
    else fs.copyFileSync(s, d);
  }
}
if (fs.existsSync(srcStyles)) {
  copyDir(srcStyles, distStyles);
}

// 2. Fix ESM relative imports: append `.js` to bare specifiers like
//    `from './layout/AppLayout'` so the resolver can find the file.
function fixImports(dir) {
  for (const entry of fs.readdirSync(dir, { withFileTypes: true })) {
    const full = path.join(dir, entry.name);
    if (entry.isDirectory()) {
      fixImports(full);
      continue;
    }
    if (!entry.name.endsWith(".js")) continue;
    const content = fs.readFileSync(full, "utf8");
    const fixed = content.replace(
      /((?:from|import)\s+['"])(\.{1,2}\/[^'"]+?)(['"])/g,
      (match, prefix, rel, quote) => {
        if (rel.endsWith(".js") || rel.endsWith(".css")) return match;
        const absDir = path.dirname(full);
        const target = path.resolve(absDir, rel);
        if (fs.existsSync(target) && fs.statSync(target).isDirectory()) {
          if (fs.existsSync(path.join(target, "index.js"))) {
            return `${prefix}${rel}/index.js${quote}`;
          }
        }
        if (fs.existsSync(`${target}.js`)) {
          return `${prefix}${rel}.js${quote}`;
        }
        return match;
      },
    );
    if (fixed !== content) fs.writeFileSync(full, fixed);
  }
}
if (fs.existsSync(distDir)) {
  fixImports(distDir);
}

console.log("Post-build: CSS copied, ESM imports fixed");