import { graphql } from "gql.tada";
import { GraphQLClient } from "graphql-request";
import { DateTime } from "luxon";

import { getValue, setValue } from "~/models/kv";
import type { Env } from "~/types/env";
import type { Title } from "~/types/title";
import { MediaFragment } from "~/types/title/mediaFragment";

const GetUpcomingTitlesQuery = graphql(
  `
    query GetUpcomingTitles(
      $page: Int!
      $airingAtLowerBound: Int!
      $airingAtUpperBound: Int!
    ) {
      Page(page: $page) {
        airingSchedules(
          notYetAired: true
          sort: TIME
          airingAt_lesser: $airingAtUpperBound
          airingAt_greater: $airingAtLowerBound
        ) {
          id
          airingAt
          timeUntilAiring
          episode
          media {
            ...Media
          }
        }
        pageInfo {
          hasNextPage
        }
      }
    }
  `,
  [MediaFragment],
);

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

export async function getUpcomingTitlesFromAnilist(env: Env) {
  const client = new GraphQLClient("https://graphql.anilist.co/");
  const lastCheckedScheduleAt = await getValue(
    env,
    "schedule_last_checked_at",
  ).then((value) => (value ? Number(value) : DateTime.now().toUnixInteger()));
  console.log(lastCheckedScheduleAt);
  const twoDaysFromNow = DateTime.now().plus({ days: 2 }).toUnixInteger();

  let currentPage = 1;
  let scheduleList: AiringSchedule[] = [];
  let shouldContinue = true;

  do {
    const { Page } = await client.request(GetUpcomingTitlesQuery, {
      page: currentPage++,
      airingAtLowerBound: lastCheckedScheduleAt,
      airingAtUpperBound: twoDaysFromNow,
    });

    const { airingSchedules, pageInfo } = Page!;
    scheduleList = scheduleList.concat(
      airingSchedules!.filter(
        (schedule): schedule is AiringSchedule => !!schedule,
      ),
    );
    shouldContinue = pageInfo?.hasNextPage ?? false;
  } while (shouldContinue);

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

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

  return scheduleList;
}