cloud creation

src/history/history-source.ts

@@ -0,0 +1,43 @@
+import { HistorySource } from './history.types';
+
+export const RAW_HISTORY_SOURCE: HistorySource = {
+  name: 'raw',
+  table: 'history_points',
+  timeColumn: 'time',
+  intervalSeconds: 0,
+};
+
+export const AGGREGATE_HISTORY_SOURCES: HistorySource[] = [
+  { name: '1m', table: 'history_1m', timeColumn: 'bucket', intervalSeconds: 60 },
+  { name: '5m', table: 'history_5m', timeColumn: 'bucket', intervalSeconds: 300 },
+  { name: '1h', table: 'history_1h', timeColumn: 'bucket', intervalSeconds: 3600 },
+  { name: '1d', table: 'history_1d', timeColumn: 'bucket', intervalSeconds: 86400 },
+];
+
+// Подбирает самый дешевый слой данных под диапазон и целевое число точек на графике.
+export function chooseHistorySource(
+  from: Date,
+  to: Date,
+  targetPoints: number,
+): HistorySource {
+  const durationSeconds = Math.max((to.getTime() - from.getTime()) / 1000, 1);
+  const desiredSeconds = durationSeconds / targetPoints;
+
+  if (desiredSeconds < 60) {
+    return RAW_HISTORY_SOURCE;
+  }
+
+  if (desiredSeconds < 300) {
+    return AGGREGATE_HISTORY_SOURCES[0];
+  }
+
+  if (desiredSeconds < 3600) {
+    return AGGREGATE_HISTORY_SOURCES[1];
+  }
+
+  if (desiredSeconds < 86400) {
+    return AGGREGATE_HISTORY_SOURCES[2];
+  }
+
+  return AGGREGATE_HISTORY_SOURCES[3];
+}