import { error } from '@sveltejs/kit';
import type { PageServerLoad, Actions } from './$types';
import { env } from '$env/dynamic/private';
import { log } from '$lib/server/logger';

const SCRAPER_URL = env.SCRAPER_API_URL ?? 'http://localhost:8080';

export interface NovelListing {
	slug: string;
	title: string;
	cover: string;
	rank: string;
	rating: string;
	chapters: string;
	url: string;
	// enriched fields (only set when sort=rank)
	author?: string;
	status?: string;
	genres?: string[];
	source_url?: string;
}

export const load: PageServerLoad = async ({ url, locals }) => {
	const page = url.searchParams.get('page') ?? '1';
	const genre = url.searchParams.get('genre') ?? 'all';
	const sort = url.searchParams.get('sort') ?? 'popular';
	const status = url.searchParams.get('status') ?? 'all';
	const q = url.searchParams.get('q') ?? '';

	let novels: NovelListing[] = [];
	let pageNum = parseInt(page, 10) || 1;
	let hasNext = false;
	let searchQuery = '';
	let searchLocalCount = 0;
	let searchRemoteCount = 0;

	// ── Search mode: ?q= overrides browse/ranking ─────────────────────────
	if (q.trim().length >= 2) {
		searchQuery = q.trim();
		const apiURL = `${SCRAPER_URL}/api/search?q=${encodeURIComponent(searchQuery)}`;
		try {
			const res = await fetch(apiURL);
			if (!res.ok) {
				log.error('browse', 'search returned error', { status: res.status });
				throw error(502, `Search failed: ${res.status}`);
			}
			const data: {
				results: NovelListing[];
				local_count: number;
				remote_count: number;
			} = await res.json();
			novels = data.results ?? [];
			searchLocalCount = data.local_count ?? 0;
			searchRemoteCount = data.remote_count ?? 0;
		} catch (e) {
			if (e instanceof Error && 'status' in e) throw e;
			log.error('browse', 'search network error', { q: searchQuery, err: String(e) });
			throw error(502, 'Could not reach search service');
		}

		return {
			novels,
			page: 1,
			hasNext: false,
			genre,
			sort,
			status,
			isAdmin: locals.user?.role === 'admin',
			searchQuery,
			searchLocalCount,
			searchRemoteCount
		};
	}

	if (sort === 'rank') {
		// Ranking view: fetch from /api/ranking which returns richer metadata.
		// Pagination and filters (genre/status) don't apply here — the ranking
		// is a single pre-computed list from the last catalogue scrape.
		const apiURL = `${SCRAPER_URL}/api/ranking`;
		try {
			const res = await fetch(apiURL);
			if (!res.ok) {
				log.error('browse', 'scraper ranking returned error', { status: res.status });
				throw error(502, `Ranking fetch failed: ${res.status}`);
			}
			const items: Array<{
				rank: number;
				slug: string;
				title: string;
				author: string;
				cover: string;
				status: string;
				genres: string[];
				source_url: string;
			}> = await res.json();
			novels = (items ?? []).map((item) => ({
				slug: item.slug,
				title: item.title,
				cover: item.cover,
				rank: item.rank != null ? `#${item.rank}` : '',
				rating: '',
				chapters: '',
				url: item.source_url ?? '',
				author: item.author,
				status: item.status,
				genres: item.genres ?? [],
				source_url: item.source_url
			}));
			pageNum = 1;
			hasNext = false;
		} catch (e) {
			if (e instanceof Error && 'status' in e) throw e;
			log.error('browse', 'scraper ranking network error', { err: String(e) });
			throw error(502, 'Could not load ranking');
		}
	} else {
		// Browse view: paginated catalogue from /api/browse.
		const params = new URLSearchParams({ page, genre, sort, status });
		const apiURL = `${SCRAPER_URL}/api/browse?${params.toString()}`;
		try {
			const res = await fetch(apiURL);
			if (!res.ok) {
				log.error('browse', 'scraper browse returned error', { status: res.status, url: apiURL });
				throw error(502, `Browse fetch failed: ${res.status}`);
			}
			const data: { novels: NovelListing[]; page: number; hasNext: boolean } = await res.json();
			novels = data.novels ?? [];
			pageNum = data.page ?? 1;
			hasNext = data.hasNext ?? false;
		} catch (e) {
			if (e instanceof Error && 'status' in e) throw e;
			log.error('browse', 'scraper browse network error', { url: apiURL, err: String(e) });
			throw error(502, 'Could not load browse page');
		}
	}

	return {
		novels,
		page: pageNum,
		hasNext,
		genre,
		sort,
		status,
		isAdmin: locals.user?.role === 'admin',
		searchQuery: '',
		searchLocalCount: 0,
		searchRemoteCount: 0
	};
};

// Admin action: trigger a full catalogue scrape (refreshes ranking + library).
export const actions: Actions = {
	refresh: async ({ locals, fetch }) => {
		if (!locals.user || locals.user.role !== 'admin') {
			throw error(403, 'Forbidden');
		}
		try {
			const res = await fetch('/api/scrape', {
				method: 'POST',
				headers: { 'Content-Type': 'application/json' },
				body: JSON.stringify({})
			});
			if (res.status === 409) return { status: 'busy' };
			if (!res.ok) return { status: 'error' };
			return { status: 'queued' };
		} catch {
			return { status: 'error' };
		}
	}
};