import type { VideoItem } from '../services/types';

export interface NormalRow {
  type: 'pair';
  left: VideoItem;
  right: VideoItem | null;
}

export interface BigRow {
  type: 'big';
  item: VideoItem;
}

export type ListRow = NormalRow | BigRow;

export function toListRows(pages: VideoItem[][]): ListRow[] {
  const rows: ListRow[] = [];
  for (const chunk of pages) {
    if (chunk.length === 0) continue;
    // Prioritize: first live item becomes BigRow
    let bigIdx = chunk.findIndex(item => item.goto === 'live');
    if (bigIdx === -1) {
      // Fallback: highest view count
      bigIdx = 0;
      let maxView = chunk[0].stat?.view ?? 0;
      for (let i = 1; i < chunk.length; i++) {
        const v = chunk[i].stat?.view ?? 0;
        if (v > maxView) { maxView = v; bigIdx = i; }
      }
    }
    const bigItem = chunk[bigIdx];
    const rest = chunk.filter((_, i) => i !== bigIdx);
    for (let i = 0; i < rest.length; i += 2) {
      rows.push({ type: 'pair', left: rest[i], right: rest[i + 1] ?? null });
    }
    rows.push({ type: 'big', item: bigItem });
  }
  return rows;
}