Function format

packages/db/src/engine/format.ts:18–171

(
  concreteSeries: ConcreteSeries[],
  definitions: Array<{
    id?: string;
    type: 'event' | 'formula';
    displayName?: string;
    formula?: string;
    name?: string;
    hideSeries?: string[];
  }>,
  includeAlphaIds: boolean,
  previousSeries: ConcreteSeries[] | null = null,
  limit: number | undefined = undefined
)

 * TODO: Migrate frontend to use cleaner ChartResponse format
 */
export function format(
  concreteSeries: ConcreteSeries[],
  definitions: Array<{
    id?: string;
    type: 'event' | 'formula';
    displayName?: string;
    formula?: string;
    name?: string;
    hideSeries?: string[];
  }>,
  includeAlphaIds: boolean,
  previousSeries: ConcreteSeries[] | null = null,
  limit: number | undefined = undefined
): FinalChart {
  // Collect definition indices that should be hidden from the chart.
  // A formula can opt to hide any of the series it references (by alpha ID)
  // so the chart only shows the formula result without the input series.
  const hiddenDefinitionIndices = new Set<number>();
  for (const definition of definitions) {
    if (definition.type !== 'formula' || !definition.hideSeries?.length) {
      continue;
    }
    for (const alphaId of definition.hideSeries) {
      const index = alphabetIds.indexOf(alphaId as (typeof alphabetIds)[number]);
      if (index >= 0) {
        hiddenDefinitionIndices.add(index);
      }
    }
  }

  const visibleConcreteSeries =
    hiddenDefinitionIndices.size > 0
      ? concreteSeries.filter(
          (cs) => !hiddenDefinitionIndices.has(cs.definitionIndex)
        )
      : concreteSeries;

  const series = visibleConcreteSeries.map((cs) => {
    // Find definition for this series
    const definition = definitions[cs.definitionIndex];
    const alphaId = includeAlphaIds
      ? alphabetIds[cs.definitionIndex]
      : undefined;

    // Build display name with optional alpha ID
    let displayName: string[];

    // Replace the first name (which is the event name) with the display name if it exists
    const names = cs.name.slice(0);
    if (cs.definition.displayName) {
      names.splice(0, 1, cs.definition.displayName);
    }
    // Add the alpha ID to the first name if it exists
    if (alphaId) {
      displayName = [`(${alphaId}) ${names[0]}`, ...names.slice(1)];
    } else {
      displayName = names;
    }