#!/usr/bin/env node
/**
 * run-link-check.mjs — markdown link-check runner (M1, S-104)
 *
 * Runs markdown-link-check across README.md, docs/, and every SKILL.md
 * (excluding node_modules and generated agent-variant directories).
 *
 * Modes:
 *   --offline  (default) — checks only repo-relative links and #anchor links.
 *              All http/https links are ignored.  Safe for CI and local dev
 *              without network access.
 *   --online   — checks all links, including external URLs, with timeouts
 *              and retries as configured in markdown-link-check.online.json.
 *
 * Exit codes:
 *   0 — all checked links are alive (or ignored in offline mode)
 *   1 — one or more broken links found
 */

import { spawnSync } from "node:child_process";
import { readdirSync, existsSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const REPO_ROOT = path.resolve(__dirname, "../..");

// ── CLI arguments ──────────────────────────────────────────────────────────

const online = process.argv.includes("--online");
const configFile = online
  ? path.join(REPO_ROOT, "markdown-link-check.online.json")
  : path.join(REPO_ROOT, "markdown-link-check.json");

// ── File discovery ─────────────────────────────────────────────────────────

const SKIP_PATHS = new Set([
  "skills/atlassian/codex",
  "skills/atlassian/claude-code",
  "skills/atlassian/cursor",
  "skills/atlassian/opencode",
  "skills/atlassian/pi",
  "skills/web-automation/claude-code",
  "skills/web-automation/cursor",
  "skills/web-automation/opencode",
  "skills/web-automation/pi",
  "pi-package",
]);

// Also skip any _source/ subdirectory within skills — canonical source files
// use relative paths calibrated to the generated location (one level shallower).
const SKIP_SEGMENT = "_source";

function shouldSkip(absPath) {
  const rel = path.relative(REPO_ROOT, absPath);
  for (const skip of SKIP_PATHS) {
    if (rel === skip || rel.startsWith(skip + path.sep)) return true;
  }
  const parts = rel.split(path.sep);
  if (parts.includes("node_modules")) return true;
  // Skip canonical _source/ directories (links calibrated to generated location)
  if (parts.includes(SKIP_SEGMENT)) return true;
  return false;
}

function collectMarkdownFiles(dir) {
  const found = [];
  let entries;
  try {
    entries = readdirSync(dir, { withFileTypes: true });
  } catch {
    return found;
  }
  for (const entry of entries) {
    const full = path.join(dir, entry.name);
    if (shouldSkip(full)) continue;
    if (entry.isDirectory()) {
      found.push(...collectMarkdownFiles(full));
    } else if (
      entry.isFile() &&
      (entry.name.endsWith(".md") || entry.name === "SKILL.md")
    ) {
      found.push(full);
    }
  }
  return found;
}

// ── Collect target files ───────────────────────────────────────────────────

const files = [
  path.join(REPO_ROOT, "README.md"),
  ...collectMarkdownFiles(path.join(REPO_ROOT, "docs")),
  ...collectMarkdownFiles(path.join(REPO_ROOT, "skills")),
].filter(existsSync);

// De-duplicate (README.md could appear twice)
const uniqueFiles = [...new Set(files)];

if (uniqueFiles.length === 0) {
  console.log("link-check: no markdown files found — nothing to check.");
  process.exit(0);
}

console.log(
  `link-check: checking ${uniqueFiles.length} file(s) ` +
    `[mode: ${online ? "online" : "offline"}]…`
);

// ── Run markdown-link-check ────────────────────────────────────────────────

const mlcBin = path.join(
  REPO_ROOT,
  "node_modules",
  ".bin",
  "markdown-link-check"
);

let failures = 0;
for (const file of uniqueFiles.sort()) {
  const result = spawnSync(
    mlcBin,
    ["--config", configFile, "--quiet", file],
    { encoding: "utf8", stdio: ["ignore", "pipe", "pipe"] }
  );
  const output = (result.stdout + result.stderr).trim();
  const rel = path.relative(REPO_ROOT, file);
  if (result.status !== 0) {
    failures += 1;
    console.error(`\n--- ${rel} ---`);
    if (output) console.error(output);
  }
}

if (failures > 0) {
  console.error(
    `\nlink-check: ${failures} file(s) have broken links. ` +
      `See docs/CLEANUP-BASELINE.md for the as-is baseline.`
  );
  process.exit(1);
} else {
  console.log("link-check: all links OK.");
  process.exit(0);
}