/**
 * Race-calendar state for season-standings sports (F1, IndyCar).
 *
 * Kept in its own leaf module rather than in `scoring-event.ts` so that
 * `simulator.ts` can read it: `scoring-event.ts` pulls in `scoring-calculator`,
 * which reaches `participant-expected-value` and back into `simulator`. This
 * file imports nothing but the database.
 */

import { eq } from "drizzle-orm";
import { database } from "~/database/context";
import * as schema from "~/database/schema";

export interface SeasonRaceCounts {
  completed: number;
  remaining: number;
  total: number;
}

/**
 * How long after the green flag a race is assumed to have finished.
 *
 * `event_starts_at` is a start time, so treating it as "already run" would
 * declare the season over the moment the finale goes green — and the simulator
 * would publish the pre-race leader as champion at 100%, from standings that do
 * not yet include the race being run. No race in these series comes close to
 * six hours, and the standings feed updates within hours of a finish.
 */
const RACE_DURATION_MS = 6 * 60 * 60 * 1000;

/**
 * Has this race already been run?
 *
 * `is_complete` wins when an admin has set it, but a racing calendar is stored
 * as "Non-Scoring" rows that nobody ever marks complete, so the date is the real
 * signal. Mirrors the Upcoming / Results Pending badge on the admin events page.
 * A race happening today is still upcoming, and a row with no date at all counts
 * as upcoming.
 *
 * @param today `now` as a `YYYY-MM-DD` string, to compare against the date-only
 *   `event_date` column.
 */
export function hasRaceRun(
  event: {
    isComplete: boolean;
    eventDate: string | null;
    eventStartsAt: Date | string | null;
  },
  now: Date,
  today: string
): boolean {
  if (event.isComplete) return true;
  if (event.eventStartsAt) {
    return new Date(event.eventStartsAt).getTime() + RACE_DURATION_MS < now.getTime();
  }
  if (event.eventDate) return event.eventDate < today;
  return false;
}

/**
 * Count the races on a season-standings calendar (F1, IndyCar).
 *
 * `event_type` has no race value, so a racing calendar is stored as
 * `schedule_event` rows — the admin default for the `season_standings` scoring
 * pattern. The only other row such a season carries is the single
 * `final_standings` event that assigns fantasy placements once the championship
 * is settled. A race is therefore "every event except `final_standings`", not
 * "every event except `schedule_event`" — getting that backwards leaves the
 * simulator with zero remaining races and no idea the season is in progress.
 */
export async function countSeasonRaces(
  sportsSeasonId: string,
  now: Date = new Date(),
  providedDb?: ReturnType<typeof database>
): Promise<SeasonRaceCounts> {
  const db = providedDb || database();

  const events = await db.query.scoringEvents.findMany({
    where: eq(schema.scoringEvents.sportsSeasonId, sportsSeasonId),
    columns: {
      eventType: true,
      isComplete: true,
      eventDate: true,
      eventStartsAt: true,
    },
  });

  const today = now.toISOString().split("T")[0];
  let completed = 0;
  let remaining = 0;

  for (const event of events) {
    if (event.eventType === "final_standings") continue;
    if (hasRaceRun(event, now, today)) completed++;
    else remaining++;
  }

  return { completed, remaining, total: completed + remaining };
}