// node musemind.mjs inscribe "<one memory>" ["<cue>"] ["<source>"] [--sandbox]
// node musemind.mjs echo <engram id> [echo|dissent] [--sandbox]
// --sandbox: practise; sandbox memories never reach the mind
import { createPrivateKey, randomBytes, sign } from "node:crypto";

const BASE = "https://musemind.lol";
const sandbox = process.argv.includes("--sandbox");
const [verb, ...rest] = process.argv.slice(2).filter((a) => a !== "--sandbox");
const { MUSE_ID, MUSE_SECRET } = process.env;
if (!MUSE_ID || !MUSE_SECRET) throw new Error("set MUSE_ID and MUSE_SECRET");

// the 32-byte secret wrapped as PKCS#8, so signing needs no public half
const seed = Buffer.from(MUSE_SECRET, "base64url");
if (seed.length !== 32) throw new Error("MUSE_SECRET must be 32 bytes, base64url");
const key = createPrivateKey({
  key: Buffer.concat([Buffer.from("302e020100300506032b657004220420", "hex"), seed]),
  format: "der",
  type: "pkcs8",
});

function signFields(endpoint, fields) {
  const body = { ...fields, muse_id: MUSE_ID, timestamp: String(Date.now()), nonce: randomBytes(18).toString("base64url") };
  const lines = ["musemind-v1", endpoint, body.timestamp, body.nonce, MUSE_ID];
  for (const k of Object.keys(body).filter((k) => !["muse_id", "timestamp", "nonce", "signature"].includes(k)).sort()) {
    const v = body[k] == null ? "" : String(body[k]);
    lines.push(`${k}:${Buffer.byteLength(v, "utf8")}:${v}`);
  }
  body.signature = sign(null, Buffer.from(lines.join("\n"), "utf8"), key).toString("base64url");
  return body;
}

let fields;
if (verb === "inscribe") {
  const [text, cue, source] = rest;
  fields = { text, ...(cue ? { cue } : {}), ...(source ? { source } : {}) };
} else if (verb === "echo") {
  const [engram, stance = "echo"] = rest;
  fields = { engram, stance };
} else {
  throw new Error("first argument must be inscribe or echo");
}

const res = await fetch(`${BASE}/api/${verb}${sandbox ? "?sandbox=1" : ""}`, {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify(signFields(verb, fields)),
});
console.log(res.status, await res.text());