#!/usr/bin/env node
// SPEC: PJ2026-01060703 CI/CD branch follower runtime GitOps verify.
// Responsibility: fail publish before Argo when rendered runtime GitOps violates UniDesk overlay gates.
import { existsSync, readdirSync, readFileSync, statSync } from "node:fs";
import path from "node:path";

const repoDir = process.cwd();
const overlay = readOverlay();
const runtimePath = requiredOverlayString("runtimePath");
const runtimeDir = path.resolve(repoDir, runtimePath);
const prometheusOperatorKinds = new Set(["ServiceMonitor", "PrometheusRule", "PodMonitor", "Probe"]);

if (!existsSync(runtimeDir)) {
  fail("runtime-path-missing", { runtimePath });
}

const checks = [];
if (overlay?.observability?.prometheusOperator === false) {
  checks.push("prometheus-operator-disabled");
  const refs = findPrometheusOperatorResources();
  if (refs.length > 0) fail("prometheus-operator-resource-present", { runtimePath, refs: refs.slice(0, 12), refCount: refs.length });
}

console.error(JSON.stringify({ event: "unidesk-runtime-gitops-verify", ok: true, runtimePath, checks }));

function findPrometheusOperatorResources() {
  const refs = [];
  for (const file of listYamlFiles(runtimeDir)) {
    const rel = path.relative(repoDir, file);
    for (const doc of splitYamlDocuments(readFileSync(file, "utf8"))) {
      refs.push(...prometheusOperatorResourceRefs(doc, rel));
    }
  }
  return refs;
}

function splitYamlDocuments(text) {
  return text.split(/^---[ \t]*(?:#.*)?$/mu).map((doc) => doc.trim()).filter(Boolean);
}

function prometheusOperatorResourceRefs(text, file) {
  const jsonRefs = prometheusOperatorJsonResourceRefs(text, file);
  if (jsonRefs !== null) return jsonRefs;
  const api = text.match(/^\s*apiVersion:\s*["']?(monitoring\.coreos\.com\/[^"'\s#]+)["']?\s*(?:#.*)?$/mu);
  const kind = text.match(/^\s*kind:\s*["']?([^"'\s#]+)["']?\s*(?:#.*)?$/mu);
  if (!api || !kind || !prometheusOperatorKinds.has(kind[1])) return [];
  const name = text.match(/^\s*name:\s*["']?([^"'\s#]+)["']?\s*(?:#.*)?$/mu);
  return [{ file, kind: kind[1], name: name ? name[1] : null, container: null }];
}

function prometheusOperatorJsonResourceRefs(text, file) {
  const parsed = parseJsonDocument(text);
  if (parsed === null) return null;
  const items = isKubernetesList(parsed) ? parsed.items : [parsed];
  return items.filter(isPrometheusOperatorResource).map((item) => ({
    file,
    kind: item.kind,
    name: typeof item.metadata?.name === "string" ? item.metadata.name : null,
    container: isKubernetesList(parsed) ? "List.items" : null,
  }));
}

function isPrometheusOperatorResource(value) {
  if (!value || typeof value !== "object" || Array.isArray(value)) return false;
  return typeof value.apiVersion === "string"
    && value.apiVersion.startsWith("monitoring.coreos.com/")
    && typeof value.kind === "string"
    && prometheusOperatorKinds.has(value.kind);
}

function isKubernetesList(value) {
  return value
    && typeof value === "object"
    && !Array.isArray(value)
    && value.apiVersion === "v1"
    && value.kind === "List"
    && Array.isArray(value.items);
}

function parseJsonDocument(text) {
  const trimmed = text.trim();
  if (!trimmed.startsWith("{") && !trimmed.startsWith("[")) return null;
  try {
    return JSON.parse(trimmed);
  } catch {
    return null;
  }
}

function listYamlFiles(root) {
  const out = [];
  for (const name of readdirSync(root)) {
    const file = path.join(root, name);
    const stat = statSync(file);
    if (stat.isDirectory()) {
      out.push(...listYamlFiles(file));
    } else if (/\.(ya?ml)$/u.test(name)) {
      out.push(file);
    }
  }
  return out.sort();
}

function readOverlay() {
  const encoded = process.env.UNIDESK_RUNTIME_GITOPS_OVERLAY_B64;
  if (!encoded) throw new Error("UNIDESK_RUNTIME_GITOPS_OVERLAY_B64 is required");
  return JSON.parse(Buffer.from(encoded, "base64").toString("utf8"));
}

function requiredOverlayString(name) {
  const value = overlay[name];
  if (typeof value !== "string" || value.length === 0) throw new Error(`overlay.${name} is required`);
  return value;
}

function fail(reason, extra = {}) {
  console.error(JSON.stringify({ event: "unidesk-runtime-gitops-verify", ok: false, reason, ...extra }));
  process.exit(48);
}