import type { AniListAuthorisation } from '$lib/AniList/identity';
import type { UserIdentity } from './identity';
import anime from '../../stores/anime';
import manga from '../../stores/manga';
import settings from '../../stores/settings';
import lastPruneTimes from '../../stores/lastPruneTimes';

export enum Type {
	Anime,
	Manga
}

export interface Media {
	id: number;
	status: string;
	type: string;
	episodes: number;
	chapters: number;
	format: string;
	title: {
		romaji: string;
		english: string;
		native: string;
	};
	nextAiringEpisode?: {
		episode: number;
		timeUntilAiring?: number;
	};
	mediaListEntry?: {
		progress: number;
		status: string;
		score: number;
		startedAt: {
			year: number;
		};
	};
	startDate: {
		year: number;
	};
	coverImage: {
		extraLarge: string;
	};
}

export const flattenLists = (lists: { entries: { media: Media }[] }[]) => {
	if (lists === undefined) {
		return [];
	}

	let flattenedList: { media: Media }[] = [];
	const minimisedList: Media[] = [];

	for (const list of lists) {
		flattenedList = flattenedList.concat(list.entries);
	}

	for (const [position, entry] of flattenedList.entries()) {
		minimisedList[position] = entry.media;
	}

	return minimisedList.filter((item, index, array) => {
		return (
			array.findIndex((i) => {
				return i.id === item.id;
			}) === index
		);
	});
};

export const mediaListCollection = async (
	anilistAuthorisation: AniListAuthorisation,
	userIdentity: UserIdentity,
	type: Type,
	mediaCache: string | undefined,
	currentLastPruneAt: string | number,
	forcePrune = false,
	includeCompleted = false
): Promise<Media[]> => {
	let currentCacheMinutes;

	settings.subscribe((value) => {
		currentCacheMinutes = value.cacheMinutes;
	});

	if (String(currentLastPruneAt) === '') {
		if (type === Type.Anime) {
			lastPruneTimes.setKey('anime', new Date().getTime());
		} else {
			lastPruneTimes.setKey('manga', new Date().getTime());
		}
	} else {
		if (
			(new Date().getTime() - Number(currentLastPruneAt)) / 1000 / 60 >
				Number(currentCacheMinutes) ||
			forcePrune
		) {
			if (type === Type.Anime) {
				lastPruneTimes.setKey('anime', new Date().getTime());
				anime.set('');
			} else {
				lastPruneTimes.setKey('manga', new Date().getTime());
				manga.set('');
			}

			mediaCache = '';
		}
	}

	if (mediaCache !== undefined && mediaCache !== '') {
		return JSON.parse(mediaCache);
	}

	const userIdResponse = await (
		await fetch('https://graphql.anilist.co', {
			method: 'POST',
			headers: {
				Authorization: `${anilistAuthorisation.tokenType} ${anilistAuthorisation.accessToken}`,
				'Content-Type': 'application/json',
				Accept: 'application/json'
			},
			body: JSON.stringify({
				query: `{ MediaListCollection(userId: ${userIdentity.id}, type: ${
					type === Type.Anime ? 'ANIME' : 'MANGA'
				}${includeCompleted ? '' : ', status_not_in: [ COMPLETED ]'}) {
            lists { entries { media {
              id
              status
              type
              episodes
							chapters
              format
              title { romaji english native }
              nextAiringEpisode { episode timeUntilAiring }
              mediaListEntry { progress status score(format: POINT_100) startedAt { year } }
              startDate { year }
							coverImage { extraLarge }
            } } }
          }
        }`
			})
		})
	).json();

	if (mediaCache === '') {
		if (type === Type.Anime) {
			anime.set(
				JSON.stringify(flattenLists(userIdResponse['data']['MediaListCollection']['lists']))
			);
		} else {
			manga.set(
				JSON.stringify(flattenLists(userIdResponse['data']['MediaListCollection']['lists']))
			);
		}
	}

	return flattenLists(userIdResponse['data']['MediaListCollection']['lists']);
};

export const publicMediaListCollection = async (userId: number, type: Type): Promise<Media[]> => {
	const userIdResponse = await (
		await fetch('https://graphql.anilist.co', {
			method: 'POST',
			headers: {
				'Content-Type': 'application/json',
				Accept: 'application/json'
			},
			body: JSON.stringify({
				query: `{ MediaListCollection(userId: ${userId}, type: ${
					type === Type.Anime ? 'ANIME' : 'MANGA'
				}, status_not_in: [ COMPLETED ]) {
            lists { entries { media {
              id
              status
              type
              episodes
              format
              title { romaji english native }
              nextAiringEpisode { episode timeUntilAiring }
              mediaListEntry { progress status }
              startDate { year }
            } } }
          }
        }`
			})
		})
	).json();

	return flattenLists(userIdResponse['data']['MediaListCollection']['lists']);
};

export const recentMediaActivities = async (
	userIdentity: UserIdentity,
	media: Media
): Promise<number | null> => {
	const activities = await (
		await fetch('https://graphql.anilist.co', {
			method: 'POST',
			headers: {
				'Content-Type': 'application/json',
				Accept: 'application/json'
			},
			body: JSON.stringify({
				query: `{
					Page(page: 1) {
						activities(mediaId: ${media.id}, sort: ID_DESC) {
							... on ListActivity { progress }
						}
					}

					MediaList(userId: ${userIdentity.id}, mediaId: ${media.id}) { progress }
				}`
			})
		})
	).json();
	// Essentially, just Automail estimation. All credit to hoh and the Automail contributors.
	let guesses: number[] = [];

	activities['data']['Page']['activities'].forEach((activity: { progress: string }) => {
		if (activity.progress !== null) {
			const progress = Number((activity.progress.match(/\d+$/) || [0])[0]);

			if (progress !== 65535) {
				guesses.push(progress);
			}
		}
	});
	guesses.sort((a, b) => b - a);

	if (guesses.length) {
		let bestGuess = guesses[0];

		if (guesses.length > 2) {
			if (guesses.filter((val) => val < 7000).length) {
				guesses = guesses.filter((val) => val < 7000);
			}

			const difference = guesses[0] - guesses[1];
			const inverseDifference = 1 + Math.ceil(25 / (difference + 1));

			if (guesses.length >= inverseDifference) {
				if (
					guesses[1] === guesses[inverseDifference] ||
					guesses[0] - guesses[1] > 500 ||
					(guesses[0] - guesses[1] > 100 && guesses[1] >= guesses[inverseDifference] - 1)
				) {
					bestGuess = guesses[1];

					if (
						guesses.length > 15 &&
						guesses[1] - guesses[2] > 50 &&
						guesses[2] === guesses[guesses.length - 1]
					) {
						bestGuess = guesses[2];
					}
				}
			}
		}

		if (activities['data']['MediaList']['progress'] !== null) {
			if (activities['data']['MediaList']['progress'] > bestGuess) {
				bestGuess = activities['data']['MediaList']['progress'];
			}
		}

		return bestGuess;
	}

	return null;
};