// UUID helpers for dev-deploy.
//
// Two flavors:
//   - randomUuid(): a fresh v4 UUID, used for newly-created ops and entities
//   - deterministicUuid(kind, name): a stable, repeatable UUID derived from
//     (namespace, kind, name) using SHA-256. Used during first-run backfill so
//     that two environments installed from the same base produce identical
//     UUIDs for the same (kind, name) pair. RFC 4122 v5 shape with namespace.

const crypto = require("crypto");

const { ID_NAMESPACE } = require("./constants");


const deterministicUuid = (kind, name) => {
    const input = `${ID_NAMESPACE}|${kind}|${name}`;
    const hash  = crypto.createHash("sha256").update(input).digest();
    const bytes = Buffer.from(hash.subarray(0, 16));
    bytes[6] = (bytes[6] & 0x0f) | 0x50;
    bytes[8] = (bytes[8] & 0x3f) | 0x80;
    const hex = bytes.toString("hex");
    return `${hex.slice(0, 8)}-${hex.slice(8, 12)}-${hex.slice(12, 16)}-${hex.slice(16, 20)}-${hex.slice(20, 32)}`;
};


const randomUuid = () => {
    return crypto.randomUUID();
};


module.exports = {
    deterministicUuid,
    randomUuid
};