/**
 * TGKey — branded type for TG session identifiers.
 * Format: "YYYY-MM-DD-SLOT" e.g. "2026-06-11-20"
 *
 * Usage:
 *   import { TGKey } from "@systems/tg-key";
 *
 *   const key = TGKey.current({ slot: 20 })
 *   const key = TGKey.from({ date: "2026-06-11", slot: 20 })
 *   TGKey.parse(key)         // { date: "2026-06-11", slot: 20 }
 *   TGKey.toHistoryPath(key) // ".../tg-history/2026-06-11-20.json"
 */

 import { Paths } from "@paths";

 export type TGKey = string & { readonly __brand: "TGKey" };
 
 export const TGKey = {
  from({ date, slot }: { date: Date | string; slot: number }): TGKey {
    const d = date instanceof Date ? date.toISOString().slice(0, 10) : date;
    const s = String(slot).padStart(2, "0");
    return `${d}-${s}` as TGKey;
  },
 
   current({ slot }: { slot: number }): TGKey {
     return TGKey.from({ date: new Date(), slot });
   },
 
   parse(key: TGKey): { date: string; slot: number } {
     const parts = key.split("-");
     return {
       date: parts.slice(0, 3).join("-"),   // "YYYY-MM-DD"
       slot: parseInt(parts[3], 10),
     };
   },
 
   toHistoryPath(key: TGKey): string {
     return Paths.data("tg-history", `${key}.json`);
   },
 
   /** Format for display: "11/06/2026 · 20:00" */
   toDisplay(key: TGKey): string {
     const { date, slot } = TGKey.parse(key);
     const [year, month, day] = date.split("-");
     return `${day}/${month}/${year} · ${slot}:00`;
   },
 
   /** Check if a string is a valid TGKey */
   isValid(key: string): key is TGKey {
     return /^\d{4}-\d{2}-\d{2}-\d{1,2}$/.test(key);
   },
 };