import type { AniListEntry, AniListMediaType, AniListProfile, AniListStat } from '#lib/anilist/types';

const cacheDuration = 60 * 60 * 1000;
const minutesPerDay = 60 * 24;
const topRatedMinimumScore = 9;

interface MediaStatistics {
	count: number;
	episodesWatched?: number;
	minutesWatched?: number;
	chaptersRead?: number;
	volumesRead?: number;
}

interface MediaConfig {
	statisticsKey: 'anime' | 'manga';
	statisticsFields: string;
	totalField: 'episodes' | 'chapters';
	listPath: string;
	currentLabel: string;
	progressUnit: string;
	totalUnit: string;
	statusLabels: Record<string, string>;
	stats: (statistics: MediaStatistics) => AniListStat[];
}

const mediaConfigs: Record<AniListMediaType, MediaConfig> = {
	ANIME: {
		statisticsKey: 'anime',
		statisticsFields: 'count episodesWatched minutesWatched',
		totalField: 'episodes',
		listPath: 'animelist',
		currentLabel: 'Currently watching',
		progressUnit: 'Episode',
		totalUnit: 'eps',
		statusLabels: { COMPLETED: 'Completed', CURRENT: 'Watching', PLANNING: 'Planning', PAUSED: 'Paused', DROPPED: 'Dropped' },
		stats: (statistics) => [
			{ label: 'Anime', value: `${statistics.count}` },
			{ label: 'Episodes', value: `${statistics.episodesWatched ?? 0}` },
			{ label: 'Watch time', value: `${Math.round(((statistics.minutesWatched ?? 0) / minutesPerDay) * 10) / 10} days` }
		]
	},
	MANGA: {
		statisticsKey: 'manga',
		statisticsFields: 'count chaptersRead volumesRead',
		totalField: 'chapters',
		listPath: 'mangalist',
		currentLabel: 'Currently reading',
		progressUnit: 'Chapter',
		totalUnit: 'ch',
		statusLabels: { COMPLETED: 'Completed', CURRENT: 'Reading', PLANNING: 'Planning', PAUSED: 'Paused', DROPPED: 'Dropped' },
		stats: (statistics) => [
			{ label: 'Manga', value: `${statistics.count}` },
			{ label: 'Chapters', value: `${statistics.chaptersRead ?? 0}` },
			{ label: 'Volumes', value: `${statistics.volumesRead ?? 0}` }
		]
	}
};

interface ResponseEntry {
	score: number;
	progress: number;
	media: {
		id: number;
		siteUrl: string;
		episodes?: number | null;
		chapters?: number | null;
		title: { english: string | null; romaji: string };
		coverImage: { large: string };
	};
}

interface AniListResponse {
	data: {
		User: {
			name: string;
			siteUrl: string;
			statistics: Record<string, MediaStatistics>;
		};
		MediaListCollection: { lists: { status: string | null; entries: ResponseEntry[] }[] };
	};
}

const profileCache = new Map<string, { profile: AniListProfile; fetchedAt: number }>();

function buildQuery(config: MediaConfig): string {
	return `
		query ($userName: String, $type: MediaType) {
			User(name: $userName) {
				name
				siteUrl
				statistics { ${config.statisticsKey} { ${config.statisticsFields} } }
			}
			MediaListCollection(userName: $userName, type: $type) {
				lists {
					status
					entries {
						score(format: POINT_10)
						progress
						media { id siteUrl ${config.totalField} title { english romaji } coverImage { large } }
					}
				}
			}
		}
	`;
}

function toEntry({ score, progress, media }: ResponseEntry, config: MediaConfig): AniListEntry {
	return {
		id: media.id,
		title: media.title.english ?? media.title.romaji,
		url: media.siteUrl,
		cover: media.coverImage.large,
		score,
		progress,
		total: media[config.totalField] ?? null
	};
}

function entriesWithStatus(response: AniListResponse, status: string, config: MediaConfig): AniListEntry[] {
	const list = response.data.MediaListCollection.lists.find((item) => item.status === status);
	return (list?.entries ?? []).map((entry) => toEntry(entry, config));
}

function toProfile(response: AniListResponse, mediaType: AniListMediaType): AniListProfile {
	const config = mediaConfigs[mediaType];
	const { name, siteUrl, statistics } = response.data.User;
	const completed = entriesWithStatus(response, 'COMPLETED', config);

	return {
		mediaType,
		name,
		profileUrl: siteUrl,
		listUrl: `${siteUrl}/${config.listPath}`,
		stats: config.stats(statistics[config.statisticsKey]),
		statusCounts: Object.entries(config.statusLabels).map(([status, label]) => ({
			status,
			label,
			count: entriesWithStatus(response, status, config).length
		})),
		current: entriesWithStatus(response, 'CURRENT', config),
		currentLabel: config.currentLabel,
		progressUnit: config.progressUnit,
		totalUnit: config.totalUnit,
		topRated: completed.filter((entry) => entry.score >= topRatedMinimumScore).sort((first, second) => second.score - first.score),
		planning: entriesWithStatus(response, 'PLANNING', config),
		completedCount: completed.length
	};
}

export async function getAniListProfile(userName: string, mediaType: AniListMediaType): Promise<AniListProfile | null> {
	const cacheKey = `${userName}:${mediaType}`;
	const cached = profileCache.get(cacheKey);
	if (cached && Date.now() - cached.fetchedAt < cacheDuration) return cached.profile;

	try {
		const response = await fetch('https://graphql.anilist.co', {
			method: 'POST',
			headers: { 'Content-Type': 'application/json', Accept: 'application/json' },
			body: JSON.stringify({ query: buildQuery(mediaConfigs[mediaType]), variables: { userName, type: mediaType } })
		});
		if (!response.ok) throw new Error(`AniList returned ${response.status}`);

		const profile = toProfile(await response.json(), mediaType);
		profileCache.set(cacheKey, { profile, fetchedAt: Date.now() });
		return profile;
	} catch (error) {
		console.error(`AniList ${mediaType.toLowerCase()} lookup failed for ${userName}:`, error);
		return cached?.profile ?? null;
	}
}