// stack/refresh.mjs — keep stack knowledge current. Read-only against DO + npm.
//
//   node --env-file=<vault>/devcontainer.env stack/refresh.mjs
//   npm run stack:refresh   (wires the env file)
//
// Pulls real DigitalOcean spend + inventory and the outdated-dependency set for
// the deployed projects, writes a dated snapshot, and prints DELTAS vs the last
// run — the actual nightly signal (spend moved, a droplet appeared, a new major
// bump landed). Does NOT touch git or the poster; the poster is a curated
// artifact you rebuild when folding fresh numbers in. Never prints secrets.

import { readFileSync, writeFileSync, readdirSync, mkdirSync, existsSync } from "fs";
import { execFileSync } from "child_process";
import { join, dirname } from "path";
import { fileURLToPath } from "url";

const HERE = dirname(fileURLToPath(import.meta.url));
const SNAPDIR = join(HERE, "snapshots");
const ROOT = join(HERE, "..");
if (!existsSync(SNAPDIR)) mkdirSync(SNAPDIR, { recursive: true });

const token = process.env.DIGITALOCEAN_ACCESS_TOKEN || process.env.DO_TOKEN;
if (!token) { console.error("no DO token in env — run via `npm run stack:refresh` or --env-file the vault"); process.exit(2); }

const doApi = async (p) => {
  const r = await fetch(`https://api.digitalocean.com/v2${p}`, { headers: { Authorization: `Bearer ${token}` } });
  return r.ok ? r.json() : { __err: `${r.status}` };
};

// ---- DigitalOcean ----
const bal = await doApi("/customers/my/balance");
const dro = await doApi("/droplets?per_page=100");
const dbs = await doApi("/databases");

const droplets = (dro.droplets || []).map((d) => ({
  name: d.name, size: d.size_slug, price: d.size?.price_monthly, region: d.region?.slug,
})).sort((a, b) => b.price - a.price);
const dropletTotal = droplets.reduce((s, d) => s + (d.price || 0), 0);
const databases = (dbs.databases || []).map((d) => ({ name: d.name, engine: `${d.engine}/${d.version}`, size: d.size, nodes: d.num_nodes }));

// ---- outdated deps (network; the deployed node projects) ----
const ncu = (dir) => {
  try {
    const out = execFileSync("npx", ["--yes", "npm-check-updates", "--jsonUpgraded", "--packageFile", join(ROOT, dir, "package.json")],
      { encoding: "utf8", stdio: ["ignore", "pipe", "ignore"], timeout: 120000 });
    return JSON.parse(out || "{}");
  } catch { return { __err: "ncu failed" }; }
};
const outdated = { system: ncu("system"), "session-server": ncu("session-server") };

// ---- assemble snapshot ----
const now = new Date();
const stamp = now.toISOString();
const day = stamp.slice(0, 10);
const snap = {
  stamp,
  do: {
    monthToDate: bal.month_to_date_usage ?? null,
    balance: bal.account_balance ?? null,
    dropletTotalMonthly: dropletTotal,
    droplets, databases,
  },
  outdated: {
    system: Object.keys(outdated.system).filter((k) => k !== "__err"),
    "session-server": Object.keys(outdated["session-server"]).filter((k) => k !== "__err"),
  },
};

// ---- delta vs previous snapshot ----
const prev = readdirSync(SNAPDIR).filter((f) => f.endsWith(".json")).sort().pop();
const before = prev ? JSON.parse(readFileSync(join(SNAPDIR, prev), "utf8")) : null;
const deltas = [];
if (before) {
  const dSpend = (snap.do.dropletTotalMonthly - before.do.dropletTotalMonthly);
  if (dSpend) deltas.push(`droplet run-rate ${dSpend > 0 ? "+" : ""}$${dSpend}/mo (now $${dropletTotal}/mo)`);
  const names = (x) => new Set(x.do.droplets.map((d) => d.name));
  const nowN = names(snap), oldN = names(before);
  for (const n of nowN) if (!oldN.has(n)) deltas.push(`NEW droplet: ${n}`);
  for (const n of oldN) if (!nowN.has(n)) deltas.push(`REMOVED droplet: ${n}`);
  for (const proj of ["system", "session-server"]) {
    const nw = new Set(snap.outdated[proj]), od = new Set(before.outdated[proj] || []);
    for (const p of nw) if (!od.has(p)) deltas.push(`${proj}: newly outdated — ${p}`);
  }
}

writeFileSync(join(SNAPDIR, `${day}.json`), JSON.stringify(snap, null, 2));

// ---- human-readable latest ----
const md = `# Stack refresh — ${day}

_Auto-generated by stack/refresh.mjs. Read-only pull of DigitalOcean spend + npm outdated._

## DigitalOcean spend
- month-to-date: **$${snap.do.monthToDate}**  ·  droplet run-rate: **$${dropletTotal}/mo**  ·  balance: $${snap.do.balance}
- droplets (${droplets.length}):
${droplets.map((d) => `  - ${d.name} — ${d.size} — $${d.price}/mo (${d.region})`).join("\n")}
- managed dbs: ${databases.map((d) => `${d.name} (${d.engine}, ${d.size}×${d.nodes})`).join("; ") || "none"}

## Outdated (majors+ available)
- system: ${snap.outdated.system.length} packages
- session-server: ${snap.outdated["session-server"].length} packages

## Changes since last run${before ? ` (${prev.replace(".json", "")})` : ""}
${deltas.length ? deltas.map((d) => `- ${d}`).join("\n") : (before ? "- no changes" : "- (first snapshot — no prior to compare)")}
`;
writeFileSync(join(HERE, "refresh-latest.md"), md);

console.log(md);
console.log(`\nsnapshot: stack/snapshots/${day}.json`);
if (deltas.length) console.log(`\n⚠️  ${deltas.length} change(s) since last run — see above`);