natural-language-postgres/lib/rechart-format.ts

import { Config } from "./types";

type InputDataPoint = Record<string, string | number>;

interface TransformedDataPoint {
  [key: string]: string | number | null;
}

interface TransformationResult {
  data: TransformedDataPoint[];
  xAxisField: string;
  lineFields: string[];
}

export function transformDataForMultiLineChart(
  data: InputDataPoint[],
  chartConfig: Config
): TransformationResult {
  // console.log("Input data:", data);
  const {xKey,lineCategories, measurementColumn } = chartConfig;

  const fields = Object.keys(data[0]);
  // console.log("Fields:", fields);

  const xAxisField = xKey ?? 'year'; // Assuming 'year' is always the x-axis
  const lineField = fields.find(field => lineCategories?.includes(data[0][field] as string)) || '';

  // console.log("X-axis field:", xAxisField);
  // console.log("Line field:", lineField);

  const xAxisValues = Array.from(new Set(data.map(item => String(item[xAxisField]))));

  // console.log("X-axis values:", xAxisValues);
  // console.log("Line categories:", lineCategories);

  const transformedData: TransformedDataPoint[] = xAxisValues.map(xValue => {
    const dataPoint: TransformedDataPoint = { [xAxisField]: xValue };
    lineCategories?.forEach(category => {
      const matchingItem = data.find(item =>
        String(item[xAxisField]) === xValue && String(item[lineField]) === category
      );
      dataPoint[category] = matchingItem ? matchingItem[measurementColumn ?? ""] : null;
    });
    return dataPoint;
  });

  transformedData.sort((a, b) => Number(a[xAxisField]) - Number(b[xAxisField]));

  // console.log("Transformed data:", transformedData);

  return {
    data: transformedData,
    xAxisField,
    lineFields: lineCategories ?? []
  };
}