import type { SignalRow, ChartConfig, TimeMode } from '@/lib/types';

const MAX_SERIES = 80;

export interface SeriesData {
  keys: string[];
  allXs: number[];
  data: (number | undefined)[][];
}

export function buildSeriesData(
  rows: SignalRow[],
  signalType: ChartConfig['signal_type'],
  timeMode: TimeMode,
): SeriesData | null {
  const seriesMap = new Map<string, Map<number, number>>();

  for (const row of rows) {
    for (const [sig, val] of [
      ['green', row.green],
      ['red', row.red],
    ] as ['green' | 'red', number | undefined][]) {
      if (signalType !== 'both' && signalType !== sig) continue;
      if (val === undefined) continue;
      const key = `${row.combinator}::${row.item_key}::${sig}`;
      const x =
        timeMode === 'tick'
          ? parseInt(row.game_tick, 10)
          : new Date(row.real_time).getTime() / 1000;
      if (!seriesMap.has(key)) seriesMap.set(key, new Map());
      seriesMap.get(key)?.set(x, val);
    }
  }

  if (seriesMap.size === 0) return null;

  const keys = [...seriesMap.keys()].slice(0, MAX_SERIES);
  const allXs = [
    ...new Set(
      keys.flatMap((k) => {
        const m = seriesMap.get(k);
        return m ? [...m.keys()] : [];
      }),
    ),
  ].sort((a, b) => a - b);

  const data = keys.map((k) => {
    const m = seriesMap.get(k);
    return m ? allXs.map((x) => m.get(x)) : []; // undefined = gap
  });

  return { keys, allXs, data };
}