import { env } from "cloudflare:workers";
import type { HonoRequest } from "hono";
import { DateTime } from "luxon";

import { maybeScheduleNextAiringEpisode } from "~/libs/maybeScheduleNextAiringEpisode";
import { getValue, setValue } from "~/models/kv";
import { filterUnreleasedTitles } from "~/models/unreleasedTitles";
import type { Title } from "~/types/title";

type AiringSchedule = {
  media: Title;
  episode: number;
  timeUntilAiring: number;
  airingAt: number;
  id: number;
};

export async function getUpcomingTitlesFromAnilist(req: HonoRequest) {
  const durableObjectId = env.ANILIST_DO.idFromName("GLOBAL");
  const stub = env.ANILIST_DO.get(durableObjectId);

  const lastCheckedScheduleAt = await getValue("schedule_last_checked_at").then(
    (value) => (value ? Number(value) : DateTime.now().toUnixInteger()),
  );
  const twoDaysFromNow = DateTime.now().plus({ days: 2 }).toUnixInteger();

  let currentPage = 1;
  let plannedToWatchTitles = new Set<number>();
  let scheduleList: AiringSchedule[] = [];
  let shouldContinue = true;

  do {
    const Page = await stub.getUpcomingTitles(
      currentPage++,
      lastCheckedScheduleAt,
      twoDaysFromNow,
    );

    if (!Page) break;

    const { airingSchedules, pageInfo } = Page;
    plannedToWatchTitles = plannedToWatchTitles.union(
      await filterUnreleasedTitles(
        airingSchedules!.map((schedule: any) => schedule!.media?.id!),
      ),
    );
    scheduleList = scheduleList.concat(
      airingSchedules!.filter(
        (schedule: any): schedule is AiringSchedule =>
          !!schedule &&
          !plannedToWatchTitles.has(schedule.media?.id) &&
          schedule.media?.countryOfOrigin === "JP" &&
          schedule.episode == 1,
      ),
    );
    shouldContinue = pageInfo?.hasNextPage ?? false;
  } while (shouldContinue);

  await Promise.all(
    Array.from(plannedToWatchTitles).map((titleId) =>
      maybeScheduleNextAiringEpisode(titleId),
    ),
  );

  if (scheduleList.length === 0) {
    return [];
  }

  await setValue(
    "schedule_last_checked_at",
    scheduleList[scheduleList.length - 1].airingAt.toString(),
  );

  return scheduleList;
}