#!/usr/bin/env node
// Monthly dependency sweep (#2229), replacing Dependabot's VERSION-UPDATE PRs.
//
// A Dependabot version-update PR carries no issue and no board card — the same
// carve-out from "every PR references an issue" that the security-update flow
// had (that half is `dependabot-alerts.mjs`, #2233, which turned those PRs off
// as well and files an issue per bump from the alerts they leave behind — so
// between them Dependabot opens no PRs against this repo at all, though its
// security ALERTS stay on, since that sweep is what consumes them).
// #2235 removed `.github/dependabot.yml` outright, so Dependabot opens
// no version-update PRs against this repo at all and this script is what
// replaced them.
//
// Once a month it runs `npm outdated` across the root install and every client
// under `clients/*` (each has its own package.json + lockfile — v2 is not a
// workspace), checks every `uses:` ref under `.github/workflows` against that
// action's highest released version, and files or updates ONE tracking issue
// listing everything behind. A maintainer picks what to bump and opens a
// normal PR against `v2/main`; there is no auto-generated PR here at all.
//
// The actions half is here rather than left on Dependabot because the
// `github-actions` entry had exactly the property #2229 exists to remove: it
// opened a grouped monthly PR carrying no `Closes #N` and no board card.
// Deleting that entry without replacing it would have left action versions
// unwatched, and `npm outdated` says nothing about actions — hence the
// separate release lookup below.
//
// Idempotent by design: the issue body starts with a fixed HTML marker
// (ISSUE_MARKER below), which is how a second run in the same month finds and
// updates the existing open issue instead of filing a duplicate.
//
// `parseOutdated`, `parseActionRefs`, `parseVersionRef`, `isActionStale`,
// `staleActions`, `highestVersionTag`, `buildIssueBody` and
// `buildClearedBody` are pure. `main()`
// shells out to `npm outdated` and `gh`, so it takes its spawn function as a
// parameter (defaulting to the real one) and `dependency-refresh.test.mjs`
// drives it with a fake — covering npm failure, create vs. edit, the milestone
// lookup and both no-op paths. `workflow_dispatch` is a production trigger,
// not a substitute for that (Copilot): the helper-only tests it replaced let a
// non-zero `npm outdated` exit report a clean sweep.

import { spawnSync } from "node:child_process";
import { readdirSync, readFileSync } from "node:fs";
import { join } from "node:path";

export const ISSUE_MARKER = "<!-- dependency-refresh:monthly-sweep -->";

/** Installs to check, relative to the repo root, and their npm-outdated label. */
export const INSTALLS = [
  { dir: ".", label: "root" },
  { dir: "clients/web", label: "clients/web" },
  { dir: "clients/cli", label: "clients/cli" },
  { dir: "clients/tui", label: "clients/tui" },
  { dir: "clients/launcher", label: "clients/launcher" },
];

/** Where the `uses:` refs this sweep checks live, relative to the repo root. */
export const WORKFLOW_DIR = ".github/workflows";

/**
 * Normalize one install's `npm outdated --json` output.
 *
 * @param {string} json raw stdout from `npm outdated --json` (may be `""` or `"{}"`)
 * @returns {Array<{name: string, current: string, wanted: string, latest: string}>}
 */
export function parseOutdated(json) {
  const trimmed = json.trim();
  if (trimmed === "") return [];
  const parsed = JSON.parse(trimmed);
  return Object.entries(parsed)
    .map(([name, info]) => ({
      name,
      current: info.current ?? "(missing)",
      wanted: info.wanted ?? info.current ?? "?",
      latest: info.latest ?? "?",
    }))
    .sort((a, b) => a.name.localeCompare(b.name));
}

/**
 * Pull every action reference out of one workflow file.
 *
 * Deliberately a line regex rather than a YAML parse: `uses:` is always a
 * scalar on its own line in this repo's workflows, and a real parser would be
 * this script's only dependency. Local (`./…`) and container (`docker://…`)
 * steps are skipped — neither has a releases feed to compare against — as is
 * an unpinned `uses:` with no `@ref` at all.
 *
 * @param {string} yaml raw contents of a workflow file
 * @returns {Array<{action: string, ref: string}>} in file order, duplicates kept
 */
export function parseActionRefs(yaml) {
  const refs = [];
  for (const line of yaml.split("\n")) {
    const match = /^\s*(?:-\s+)?uses:\s*(?:"([^"]+)"|'([^']+)'|([^\s#]+))/.exec(
      line,
    );
    if (!match) continue;
    const uses = match[1] ?? match[2] ?? match[3];
    if (uses.startsWith("./") || uses.startsWith("docker://")) continue;
    const at = uses.lastIndexOf("@");
    if (at === -1) continue;
    refs.push({ action: uses.slice(0, at), ref: uses.slice(at + 1) });
  }
  return refs;
}

/**
 * Split a `v`-prefixed numeric ref into its components, or `null` when it is
 * not one — a SHA pin or a branch name, which a tag comparison cannot rank.
 *
 * @param {string} ref e.g. `v7`, `v7.0`, `7.0.1`
 * @returns {number[] | null}
 */
export function parseVersionRef(ref) {
  const match = /^v?(\d+)(?:\.(\d+))?(?:\.(\d+))?$/.exec(ref);
  if (!match) return null;
  return match
    .slice(1)
    .filter((part) => part !== undefined)
    .map(Number);
}

/**
 * Is `current` behind `latest`?
 *
 * Compared only to the precision `current` actually specifies, because that is
 * what pinning to it means: `v7` is a moving major tag that GitHub repoints at
 * every `v7.x` release, so `v7` against a latest of `v7.0.1` is up to date and
 * only `v8` makes it stale. An exactly-pinned `v7.0.0` *is* behind `v7.0.1`.
 *
 * @param {string} current the `uses:` ref
 * @param {string} latest the action's latest release tag
 * @returns {boolean} `false` when either side is not a numeric ref
 */
export function isActionStale(current, latest) {
  const from = parseVersionRef(current);
  const to = parseVersionRef(latest);
  if (from === null || to === null) return false;
  for (let i = 0; i < from.length; i++) {
    const other = to[i] ?? 0;
    if (other !== from[i]) return other > from[i];
  }
  return false;
}

/**
 * @param {Array<{action: string, ref: string}>} refs every ref found across the workflows
 * @param {Record<string, string | null>} latestByAction latest release tag per action, `null` when unknown
 * @returns {Array<{action: string, current: string, latest: string}>} the stale ones, deduped and sorted
 */
export function staleActions(refs, latestByAction) {
  const stale = new Map();
  for (const { action, ref } of refs) {
    const latest = latestByAction[action];
    if (!latest || !isActionStale(ref, latest)) continue;
    stale.set(`${action}@${ref}`, { action, current: ref, latest });
  }
  return [...stale.values()].sort(
    (a, b) =>
      a.action.localeCompare(b.action) || a.current.localeCompare(b.current),
  );
}

/**
 * @param {Array<{label: string, packages: ReturnType<typeof parseOutdated>}>} installs
 * @param {ReturnType<typeof staleActions>} actions
 * @returns {string | null} the issue body, or `null` when nothing is behind anywhere
 */
export function buildIssueBody(installs, actions = []) {
  const withPackages = installs.filter((i) => i.packages.length > 0);
  if (withPackages.length === 0 && actions.length === 0) return null;

  const sections = withPackages.map(({ label, packages }) => {
    const rows = packages
      .map(
        (p) => `| \`${p.name}\` | ${p.current} | ${p.wanted} | ${p.latest} |`,
      )
      .join("\n");
    return `### \`${label}\`\n\n| Package | Current | Wanted | Latest |\n| --- | --- | --- | --- |\n${rows}`;
  });

  if (actions.length > 0) {
    const rows = actions
      .map((a) => `| \`${a.action}\` | ${a.current} | ${a.latest} |`)
      .join("\n");
    sections.push(
      `### GitHub Actions\n\n| Action | Current | Latest |\n| --- | --- | --- |\n${rows}`,
    );
  }

  return [
    ISSUE_MARKER,
    "Routine dependency refresh — `npm outdated` plus a workflow `uses:` check, run against `v2/main` on a monthly schedule. This sweep replaces Dependabot's version-update PRs (#2229, #2235); its security-update PRs are off too (#2233), and the alerts they used to act on are swept into their own issues daily.",
    "",
    "This is a tracking issue, not a diff: pick what's worth bumping (`wanted` is the safe default; `latest` may cross a major and needs its own judgment call, especially for anything root-declared per [Dependency placement](https://github.com/modelcontextprotocol/inspector/blob/v2/main/AGENTS.md#dependency-placement)) and open a normal PR against `v2/main`.",
    "",
    ...sections,
    "",
    "A second run of this sweep before this issue closes updates this body in place rather than filing a duplicate.",
  ].join("\n");
}

/**
 * The body a still-open tracking issue is rewritten to once every install AND
 * every workflow action is current again. Without it the issue keeps its last
 * table forever and reads as live work that no longer exists (Copilot).
 *
 * It has to speak for both halves of the sweep: once actions are in scope
 * (#2235), npm-only wording here would assert a clean bill of health the sweep
 * never checked, which is the same silent-all-clear shape the rest of this
 * file guards against.
 *
 * The sweep rewrites rather than closes: it deliberately takes no board
 * actions (see the workflow header), and closing an issue whose card a
 * maintainer has already moved would make the board claim work shipped that
 * this script cannot verify shipped. A maintainer closes it.
 *
 * @param {string} isoDate the sweep date, as `YYYY-MM-DD`
 * @returns {string}
 */
export function buildClearedBody(isoDate) {
  return [
    ISSUE_MARKER,
    `Everything this sweep can check is current as of ${isoDate} — no npm package is outdated at the root or in any client, and no version-pinned workflow \`uses:\` ref is behind its action's highest release.`,
    "",
    "Refs pinned to a commit SHA or a branch are deliberately **not** covered by that statement: neither can be ranked against a release tag, so this sweep says nothing about them either way.",
    "",
    "This issue was filed by an earlier run of the monthly sweep (#2229, #2235) and its tables are gone because nothing they listed is behind any more. Either it was bumped or the ranges caught up; nothing here is outstanding.",
    "",
    "Safe to close. A later sweep that finds something behind will refile this body with fresh tables rather than open a duplicate.",
  ].join("\n");
}

function runOutdated(dir, spawn) {
  const result = spawn("npm", ["outdated", "--json"], {
    cwd: dir,
    encoding: "utf8",
  });
  if (result.error) throw result.error;
  // `npm outdated` exits 0 when everything is current and 1 when it finds
  // something outdated — both are successful runs. Every other status is a
  // real failure (a registry or config error exits 2), and it MUST throw
  // rather than fall through: a failed run also prints nothing to stdout, so
  // accepting it parses to an empty package list and reports a clean no-op.
  // With five installs swept in a loop, that turns a total outage into a
  // silent "nothing to do" (Copilot).
  if (result.status !== 0 && result.status !== 1) {
    throw new Error(
      `npm outdated failed in ${dir} (exit ${result.status}): ${(result.stderr ?? "").trim()}`,
    );
  }
  return result.stdout ?? "";
}

function collectActionRefs() {
  return readdirSync(WORKFLOW_DIR)
    .filter((file) => /\.ya?ml$/.test(file))
    .flatMap((file) =>
      parseActionRefs(readFileSync(join(WORKFLOW_DIR, file), "utf8")),
    );
}

/**
 * The highest parseable version among these tags, or `null` if none parse.
 *
 * Deliberately NOT `releases/latest`, which is GitHub's *designated* most
 * recent release rather than the greatest version: an action that ships a
 * maintenance release for an older major (a `v6.9.1` cut after `v8.0.0`) makes
 * `releases/latest` report `v6.9.1`, and a workflow pinned to `v7` would then
 * compare against v6 and read as current — silently missing a whole major
 * upgrade, which is the one thing this check exists to catch (Copilot).
 *
 * @param {string[]} tags release tag names, in any order
 * @returns {string | null}
 */
export function highestVersionTag(tags) {
  let best = null;
  let bestParts = null;
  for (const tag of tags) {
    const parts = parseVersionRef(tag);
    if (parts === null) continue;
    if (bestParts === null || comparePadded(parts, bestParts) > 0) {
      best = tag;
      bestParts = parts;
    }
  }
  return best;
}

/** Compare two version component arrays, padding the shorter with zeroes. */
function comparePadded(a, b) {
  for (let i = 0; i < Math.max(a.length, b.length); i++) {
    const diff = (a[i] ?? 0) - (b[i] ?? 0);
    if (diff !== 0) return diff;
  }
  return 0;
}

/**
 * The action's highest released version tag.
 *
 * Reads the release *list* rather than `releases/latest`, for the reason on
 * `highestVersionTag`. Drafts and prereleases are excluded — neither is
 * something a workflow should be told to move to.
 *
 * EVERY page is fetched, not just the newest 100. The list comes back
 * newest-first, which is ordering by release date and not by version: an
 * action that keeps cutting maintenance releases on lower majors pushes the
 * genuine maximum off page 1, and ranking what remains would report a lower
 * major as highest — recreating the exact false-current result that dropping
 * `releases/latest` was meant to prevent (Copilot). Paginating is the only
 * way the "highest released version" this function promises is actually that.
 *
 * @returns {string | null} `null` ONLY for a successful response carrying no
 *   usable release — an action that has never cut one, or whose tags are all
 *   unparseable. A failed lookup is never `null`; see below.
 * @throws on any non-zero status, 404 included
 */
function latestReleaseTag(action, spawn) {
  // `owner/repo/subpath@ref` is a valid `uses:`; releases live on `owner/repo`.
  const repo = action.split("/").slice(0, 2).join("/");
  const result = spawn(
    "gh",
    [
      "api",
      "--paginate",
      `repos/${repo}/releases?per_page=100`,
      "--jq",
      '[.[] | select(.draft == false and .prerelease == false) | .tag_name] | join("\\n")',
    ],
    { encoding: "utf8" },
  );
  if (result.error) throw result.error;
  // EVERY non-zero status is fatal, 404 included. This is the release *list*
  // endpoint, which answers "no releases" with a successful empty array — so a
  // 404 here does not mean "this action cuts no releases", it means the
  // repository is missing or inaccessible, i.e. a `uses:` ref this sweep
  // cannot check at all. Converting that to `null` would silently drop a
  // broken or renamed action from the sweep that replaced Dependabot
  // (Copilot). The empty-array case is already handled by the parse below.
  if (result.status !== 0) {
    throw new Error(
      `release lookup for ${repo} failed (exit ${result.status}): ${(result.stderr ?? "").trim()}`,
    );
  }
  const tags = result.stdout
    .split("\n")
    .map((line) => line.trim())
    .filter(Boolean);
  return highestVersionTag(tags);
}

function findExistingIssue(repo, spawn) {
  const result = spawn(
    "gh",
    [
      "issue",
      "list",
      "--repo",
      repo,
      "--state",
      "open",
      "--search",
      ISSUE_MARKER,
      "--json",
      "number,body",
      "--limit",
      "10",
    ],
    { encoding: "utf8" },
  );
  if (result.status !== 0) {
    throw new Error(`gh issue list failed: ${result.stderr}`);
  }
  const issues = JSON.parse(result.stdout || "[]");
  return issues.find((i) => i.body?.startsWith(ISSUE_MARKER)) ?? null;
}

function currentMilestone(repo, spawn) {
  const result = spawn(
    "gh",
    [
      "api",
      `repos/${repo}/milestones`,
      "--jq",
      'map(select(.state=="open")) | sort_by(.due_on) | .[0].title // empty',
    ],
    { encoding: "utf8" },
  );
  if (result.status !== 0) {
    throw new Error(`milestone lookup failed: ${result.stderr}`);
  }
  return result.stdout.trim() || null;
}

function editIssue(repo, number, body, spawn) {
  const edit = spawn(
    "gh",
    ["issue", "edit", String(number), "--repo", repo, "--body", body],
    { encoding: "utf8" },
  );
  if (edit.status !== 0)
    throw new Error(`gh issue edit failed: ${edit.stderr}`);
}

export function main(repo = process.env.GITHUB_REPOSITORY, spawn = spawnSync) {
  if (!repo) throw new Error("repo not specified (GITHUB_REPOSITORY unset)");

  const installs = INSTALLS.map(({ dir, label }) => ({
    label,
    packages: parseOutdated(runOutdated(dir, spawn)),
  }));

  const refs = collectActionRefs();
  const latestByAction = Object.fromEntries(
    [...new Set(refs.map((r) => r.action))].map((action) => [
      action,
      latestReleaseTag(action, spawn),
    ]),
  );
  const actions = staleActions(refs, latestByAction);

  // Look the existing issue up BEFORE branching on `body`: the nothing-
  // behind case still has to reach an open issue to clear it.
  const existing = findExistingIssue(repo, spawn);
  const body = buildIssueBody(installs, actions);

  if (body === null) {
    if (!existing) {
      console.log(
        "dependency-refresh: nothing outdated, no stale actions — no-op",
      );
      return;
    }
    editIssue(
      repo,
      existing.number,
      buildClearedBody(new Date().toISOString().slice(0, 10)),
      spawn,
    );
    console.log(
      `dependency-refresh: nothing behind — cleared stale list on #${existing.number}`,
    );
    return;
  }

  if (existing) {
    editIssue(repo, existing.number, body, spawn);
    console.log(`dependency-refresh: updated existing #${existing.number}`);
    return;
  }

  const milestone = currentMilestone(repo, spawn);
  const args = [
    "issue",
    "create",
    "--repo",
    repo,
    "--title",
    "chore(deps): monthly dependency refresh",
    "--label",
    "v2",
    "--label",
    "chore",
    "--label",
    "dependabot",
    "--body",
    body,
  ];
  if (milestone) args.push("--milestone", milestone);

  const create = spawn("gh", args, { encoding: "utf8" });
  if (create.status !== 0)
    throw new Error(`gh issue create failed: ${create.stderr}`);
  if (!milestone) {
    // Unmilestoned means unapproved, so triage sweeps it into `Incoming` — NOT
    // `Todo`, which asserts a maintainer signed off (Copilot).
    console.log(
      "dependency-refresh: no open milestone — issue filed unmilestoned, will be swept into Incoming at next triage",
    );
  }
  console.log(`dependency-refresh: filed ${create.stdout.trim()}`);
}

if (import.meta.url === `file://${process.argv[1]}`) {
  main();
}