feat(datapoints): add datapoint manager with CRUD and transform support (Task 6)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

display/middleware/src/modules/datapoints/datapoint-manager.ts

@@ -0,0 +1,136 @@
+import { getDb } from '../../db/index';
+import { applyTransform, type TransformConfig } from './transforms';
+
+export interface Datapoint {
+  id: number;
+  name: string;
+  label: string;
+  unit: string | null;
+  value: string | null;
+  status: string;
+  source_type: string;
+  source_id: number;
+  topic_id: number | null;
+  query_id: number | null;
+  transform: string | null;
+  enabled: number;
+  updated_at: string;
+}
+
+export interface DatapointUpdate {
+  label?: string;
+  unit?: string;
+  transform?: string | null;
+  enabled?: number;
+}
+
+export function getAllDatapoints(): Datapoint[] {
+  const db = getDb();
+  return db
+    .prepare('SELECT * FROM datapoints WHERE enabled = 1')
+    .all() as Datapoint[];
+}
+
+export function getDatapointById(id: number): Datapoint | undefined {
+  const db = getDb();
+  return db
+    .prepare('SELECT * FROM datapoints WHERE id = ?')
+    .get(id) as Datapoint | undefined;
+}
+
+export function updateDatapointValue(id: number, rawValue: string): Datapoint | undefined {
+  const db = getDb();
+  const dp = db.prepare('SELECT * FROM datapoints WHERE id = ?').get(id) as Datapoint | undefined;
+  if (!dp) return undefined;
+
+  let config: TransformConfig | null = null;
+  if (dp.transform) {
+    try {
+      config = JSON.parse(dp.transform) as TransformConfig;
+    } catch {
+      config = null;
+    }
+  }
+
+  const transformed = applyTransform(rawValue, config);
+
+  db.run(
+    `UPDATE datapoints SET value = ?, status = 'ok', updated_at = datetime('now') WHERE id = ?`,
+    [transformed, id]
+  );
+
+  return db.prepare('SELECT * FROM datapoints WHERE id = ?').get(id) as Datapoint | undefined;
+}
+
+export function updateDatapoint(id: number, data: DatapointUpdate): Datapoint | undefined {
+  const db = getDb();
+  const fields: string[] = [];
+  const values: unknown[] = [];
+
+  if (data.label !== undefined) {
+    fields.push('label = ?');
+    values.push(data.label);
+  }
+  if (data.unit !== undefined) {
+    fields.push('unit = ?');
+    values.push(data.unit);
+  }
+  if (data.transform !== undefined) {
+    fields.push('transform = ?');
+    values.push(data.transform);
+  }
+  if (data.enabled !== undefined) {
+    fields.push('enabled = ?');
+    values.push(data.enabled);
+  }
+
+  if (fields.length === 0) return getDatapointById(id);
+
+  values.push(id);
+  db.run(`UPDATE datapoints SET ${fields.join(', ')} WHERE id = ?`, values);
+  return getDatapointById(id);
+}
+
+export function createDatapointFromMqtt(
+  brokerId: number,
+  topicId: number,
+  topicPath: string
+): Datapoint {
+  const db = getDb();
+  const result = db.run(
+    `INSERT INTO datapoints (name, label, source_type, source_id, topic_id, enabled)
+     VALUES (?, ?, 'mqtt', ?, ?, 1)`,
+    [topicPath, topicPath, brokerId, topicId]
+  );
+  const id = result.lastInsertRowid as number;
+  return db.prepare('SELECT * FROM datapoints WHERE id = ?').get(id) as Datapoint;
+}
+
+export function createDatapointFromPg(
+  sourceId: number,
+  queryId: number,
+  queryName: string
+): Datapoint {
+  const db = getDb();
+  const result = db.run(
+    `INSERT INTO datapoints (name, label, source_type, source_id, query_id, enabled)
+     VALUES (?, ?, 'postgresql', ?, ?, 1)`,
+    [queryName, queryName, sourceId, queryId]
+  );
+  const id = result.lastInsertRowid as number;
+  return db.prepare('SELECT * FROM datapoints WHERE id = ?').get(id) as Datapoint;
+}
+
+export function getDatapointByTopicId(topicId: number): Datapoint | undefined {
+  const db = getDb();
+  return db
+    .prepare('SELECT * FROM datapoints WHERE topic_id = ?')
+    .get(topicId) as Datapoint | undefined;
+}
+
+export function getDatapointByQueryId(queryId: number): Datapoint | undefined {
+  const db = getDb();
+  return db
+    .prepare('SELECT * FROM datapoints WHERE query_id = ?')
+    .get(queryId) as Datapoint | undefined;
+}