/**
 * Shared CSV export modifiers for chart widgets
 */

/**
 * Flattens object array data into CSV-ready rows.
 * Used by bar, pie, histogram, and timeseries widgets.
 *
 * @param data - Array of series, where each series is an array of data objects
 * @returns CSV rows with headers and values
 */
export function flattenObjectArrayToCSV<T extends Record<string, unknown>>(
  data: T[][],
): string[][] {
  const rows: string[][] = []

  // Add headers from first data point if available
  if (data.length > 0 && (data[0]?.length ?? 0) > 0) {
    const firstDataPoint = data?.[0]?.[0] ?? {}
    const headers = Object.keys(firstDataPoint)
    rows.push(headers)
  }

  // Add data rows from all series
  data.forEach((series) => {
    series.forEach((dataPoint) => {
      const values = Object.values(dataPoint).map((v) => String(v))
      rows.push(values)
    })
  })

  return rows
}

/**
 * Creates CSV rows for scatterplot data.
 * Scatterplot uses array format [x, y] instead of objects.
 *
 * @param data - Array of series, where each series is an array of [x, y] tuples
 * @returns CSV rows with ['x', 'y'] headers
 */
export function scatterplotDataToCSV(data: number[][][]): string[][] {
  const rows: string[][] = []

  // Add headers
  rows.push(['x', 'y'])

  // Add data rows from all series
  data.forEach((series) => {
    series.forEach((dataPoint) => {
      rows.push([String(dataPoint[0]), String(dataPoint[1])])
    })
  })

  return rows
}