// SPDX-FileCopyrightText: © 2026 Jeffrey C. Ollie <jeff@ocjtech.us>
// SPDX-License-Identifier: MIT

// Finding the validation cases in the site's SuperMD sources. Shared by
// tools/check-cases.mjs, which runs them in libghostty-vt, and
// emulators/harness.mjs, which runs them in a real terminal.

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

export function* walk(dir) {
  for (const name of readdirSync(dir).sort()) {
    const path = join(dir, name);
    if (statSync(path).isDirectory()) yield* walk(path);
    else if (name.endsWith(".smd")) yield path;
  }
}

// A case in SuperMD source: a quote block opened by a `vt-case` block
// directive and holding two fenced code blocks, after a heading.
export function* extractCases(source) {
  const lines = source.split("\n");
  let heading = "Case";
  for (let i = 0; i < lines.length; i++) {
    const h = /^#+\s+(.*)$/.exec(lines[i]);
    if (h) heading = h[1];
    const d = /^>\s*\[\]\(\$block\.attrs\(([^)]*)\)/.exec(lines[i]);
    if (!d) continue;
    const attrs = Array.from(d[1].matchAll(/"([^"]*)"/g), (m) => m[1]);
    if (!attrs.includes("vt-case")) continue;
    const body = [];
    for (i++; i < lines.length && lines[i].startsWith(">"); i++) body.push(lines[i].replace(/^> ?/, ""));
    const fences = [];
    let current = null;
    for (const line of body) {
      if (/^```/.test(line)) {
        if (current === null) current = [];
        else {
          fences.push(current.join("\n"));
          current = null;
        }
      } else if (current !== null) current.push(line);
    }
    yield { heading, attrs, line: i, fences };
  }
}