phase 9 notification toggles (per-alert, per-category, master; default-disabled)

services/notificationEnabled.js

@@ -0,0 +1,102 @@
+/**
+ * Canonical enable/disable state accessor for per-alert notifications.
+ *
+ * State lives in two CONFIG keys:
+ *   - NOTIFICATIONS_MASTER_ENABLED (boolean) — global kill switch
+ *   - NOTIFICATION_ENABLED_JSON     (JSON string → flat { [key]: boolean })
+ *
+ * Defaults: master off, every key off. Unknown keys in the JSON are ignored
+ * on read (registry is the source of truth); keys missing from the JSON are
+ * treated as false. Master off short-circuits every read — isEnabled never
+ * returns true when master is off, so checkers bail without logs or metrics.
+ *
+ * Setters mutate CONFIG in memory and return the new value so the caller can
+ * persist it via configPersistence.applyConfigUpdates. .env writes happen
+ * there so schema validation and partial-success semantics stay consistent.
+ */
+'use strict';
+
+const { CONFIG } = require('../config');
+const { REGISTRY } = require('./notificationRegistry');
+
+function parseState() {
+  const raw = CONFIG.NOTIFICATION_ENABLED_JSON;
+  if (raw === undefined || raw === null || raw === '') return {};
+  if (typeof raw === 'object' && !Array.isArray(raw)) return raw;
+  try {
+    const parsed = JSON.parse(String(raw));
+    if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) return parsed;
+  } catch (_) {}
+  return {};
+}
+
+function isMasterOn() {
+  const v = CONFIG.NOTIFICATIONS_MASTER_ENABLED;
+  return v === true || v === 'true';
+}
+
+function isEnabled(alertKey) {
+  if (!isMasterOn()) return false;
+  const state = parseState();
+  return state[alertKey] === true;
+}
+
+function isCategoryEnabled(category) {
+  if (!isMasterOn()) return false;
+  const entries = REGISTRY[category];
+  if (!Array.isArray(entries) || entries.length === 0) return false;
+  const state = parseState();
+  return entries.every(e => state[e.key] === true);
+}
+
+function getAllState() {
+  const state = parseState();
+  const perKey = {};
+  for (const entries of Object.values(REGISTRY)) {
+    if (!Array.isArray(entries)) continue;
+    for (const e of entries) {
+      perKey[e.key] = state[e.key] === true;
+    }
+  }
+  return { master: isMasterOn(), perKey };
+}
+
+function serialize(state) {
+  const ordered = {};
+  Object.keys(state).sort().forEach(k => { ordered[k] = state[k] === true; });
+  return JSON.stringify(ordered);
+}
+
+function setKeyEnabled(key, enabled) {
+  const state = parseState();
+  state[String(key)] = enabled === true;
+  const json = serialize(state);
+  CONFIG.NOTIFICATION_ENABLED_JSON = json;
+  return json;
+}
+
+function setCategoryEnabled(category, enabled) {
+  const state = parseState();
+  const entries = REGISTRY[category];
+  if (Array.isArray(entries)) {
+    for (const e of entries) state[e.key] = enabled === true;
+  }
+  const json = serialize(state);
+  CONFIG.NOTIFICATION_ENABLED_JSON = json;
+  return json;
+}
+
+function setMasterEnabled(enabled) {
+  const value = enabled === true;
+  CONFIG.NOTIFICATIONS_MASTER_ENABLED = value;
+  return value;
+}
+
+module.exports = {
+  isEnabled,
+  isCategoryEnabled,
+  getAllState,
+  setKeyEnabled,
+  setCategoryEnabled,
+  setMasterEnabled
+};