/**
 * Patch: guard against null content.text in post view template.
 *
 * content.njk calls `property.text | markdown` but property.text can be null
 * when a post was published with empty body (draft with no content). The
 * markdown filter throws "Input data should be a String" on null input.
 *
 * Fix: coerce null/undefined to empty string via Nunjucks `or ''`.
 */
import { access, readFile, writeFile } from "node:fs/promises";

const candidates = [
  "node_modules/@rmdes/indiekit-endpoint-posts/includes/post-types/content.njk",
  "node_modules/@indiekit/endpoint-posts/includes/post-types/content.njk",
];

const marker = "[patch] content-null-guard";
const oldSnippet = `{{ prose({
  html: property.text | markdown
}) if property }}`;
const newSnippet = `{# ${marker} #}
{{ prose({
  html: (property.text or '') | markdown
}) if property }}`;

async function exists(p) {
  try { await access(p); return true; } catch { return false; }
}

let patched = 0;
for (const filePath of candidates) {
  if (!(await exists(filePath))) continue;
  const source = await readFile(filePath, "utf8");
  if (source.includes(marker)) { console.log(`[postinstall] content-null-guard already applied: ${filePath}`); continue; }
  if (!source.includes(oldSnippet)) { console.log(`[postinstall] content-null-guard: snippet not found in ${filePath}`); continue; }
  await writeFile(filePath, source.replace(oldSnippet, newSnippet), "utf8");
  patched++;
}

console.log(patched > 0
  ? `[postinstall] Patched content-null-guard in ${patched} file(s)`
  : "[postinstall] content-null-guard: nothing to patch");