// src/lib/backlink/planning-logic.ts — helpers purs du planning netlinking.

/** Bornes de mois (UTC, ISO date) pour la cadence. */
export function monthBounds(now: Date): {
  thisMonthStart: string;
  lastMonthStart: string;
  nextMonthStart: string;
} {
  const y = now.getUTCFullYear();
  const m = now.getUTCMonth();
  const iso = (yy: number, mm: number) =>
    new Date(Date.UTC(yy, mm, 1)).toISOString().slice(0, 10);
  return {
    thisMonthStart: iso(y, m),
    lastMonthStart: iso(y, m - 1),
    nextMonthStart: iso(y, m + 1),
  };
}

/** Fichier disavow Google : `domain:x.com`, dédupliqué, trié. */
export function buildDisavowFile(domains: string[]): string {
  return [...new Set(domains)]
    .sort()
    .map((d) => `domain:${d}`)
    .join("\n");
}