'use strict';

const Promise = require('bluebird');

const argv = require('./argv');
const include = require('./utils/argv-include')(argv);
const logger = require('./logger')(__filename);
const knex = require('./knex');
const scrapers = require('./scrapers/scrapers');
const { curateSites } = require('./sites');
const { curateNetworks } = require('./networks');

function urlToSiteSlug(url) {
	try {
		const slug = new URL(url)
			.hostname
			.match(/([\w-]+)\.\w+$/)?.[1];

		return slug;
	} catch (error) {
		logger.warn(`Failed to derive site slug from '${url}': ${error.message}`);

		return null;
	}
}

async function findSites(baseReleases) {
	const baseReleasesWithoutSite = baseReleases.filter(release => release.url && !release.site);

	const siteSlugs = Array.from(new Set(
		baseReleasesWithoutSite
			.map(baseRelease => urlToSiteSlug(baseRelease.url))
			.filter(Boolean),
	));

	const siteEntries = await knex('sites')
		.leftJoin('networks', 'networks.id', 'sites.network_id')
		.select('sites.*', 'networks.name as network_name', 'networks.slug as network_slug', 'networks.url as network_url', 'networks.parameters as network_parameters', 'networks.description as network_description')
		.whereIn('sites.slug', siteSlugs);

	const networkEntries = await knex('networks').whereIn('slug', siteSlugs);

	const sites = await curateSites(siteEntries, true, false);
	const networks = await curateNetworks(networkEntries, true, false, false);
	const markedNetworks = networks.map(network => ({ ...network, isNetwork: true }));

	const sitesBySlug = []
		.concat(markedNetworks, sites)
		.reduce((accSites, site) => ({ ...accSites, [site.slug]: site }), {});

	return sitesBySlug;
}

function toBaseReleases(baseReleasesOrUrls) {
	return baseReleasesOrUrls
		.map((baseReleaseOrUrl) => {
			if (baseReleaseOrUrl.url) {
				// base release with URL
				return {
					...baseReleaseOrUrl,
					deep: false,
				};
			}

			if (/^http/.test(baseReleaseOrUrl)) {
				// URL
				return {
					url: baseReleaseOrUrl,
					deep: false,
				};
			}

			if (typeof baseReleaseOrUrl === 'object' && !Array.isArray(baseReleaseOrUrl)) {
				// base release without URL, prepare for passthrough
				return {
					...baseReleaseOrUrl,
					deep: false,
				};
			}

			logger.warn(`Malformed base release, discarding '${baseReleaseOrUrl}'`);
			return null;
		})
		.filter(Boolean);
}

async function scrapeRelease(baseRelease, sites, type = 'scene') {
	const site = baseRelease.site || sites[urlToSiteSlug(baseRelease.url)];
	const siteWithFallbackNetwork = site.isNetwork ? { ...site, network: site } : site; // make site.network available, even when site is network fallback

	if (!site) {
		logger.warn(`No site available for ${baseRelease.url}`);
		return baseRelease;
	}

	if ((!baseRelease.url && !baseRelease.path) || !argv.deep) {
		return {
			...baseRelease,
			site,
		};
	}

	const scraper = scrapers.releases[site.slug] || scrapers.releases[site.network.slug];

	if (!scraper) {
		logger.warn(`Could not find scraper for ${baseRelease.url}`);
		return baseRelease;
	}

	if ((type === 'scene' && !scraper.fetchScene) || (type === 'movie' && !scraper.fetchMovie)) {
		logger.warn(`The '${site.name}'-scraper cannot fetch individual ${type}s`);
		return baseRelease;
	}

	try {
		logger.verbose(`Fetching ${type} ${baseRelease.url}`);

		const scrapedRelease = type === 'scene'
			? await scraper.fetchScene(baseRelease.url, siteWithFallbackNetwork, baseRelease, null, include)
			: await scraper.fetchMovie(baseRelease.url, siteWithFallbackNetwork, baseRelease, null, include);

		const mergedRelease = {
			...baseRelease,
			...scrapedRelease,
			deep: !!scrapedRelease,
			site,
		};

		if (scrapedRelease && baseRelease?.tags) {
			// accumulate all available tags
			mergedRelease.tags = baseRelease.tags.concat(scrapedRelease.tags);
		}

		return mergedRelease;
	} catch (error) {
		logger.error(`Deep scrape failed for ${baseRelease.url}: ${error.message}`);
		return baseRelease;
	}
}

async function scrapeReleases(baseReleases, sites, type) {
	return Promise.map(
		baseReleases,
		async baseRelease => scrapeRelease(baseRelease, sites, type),
		{ concurrency: 10 },
	);
}

async function fetchReleases(baseReleasesOrUrls, type = 'scene') {
	const baseReleases = toBaseReleases(baseReleasesOrUrls);
	const sites = await findSites(baseReleases);

	const deepReleases = await scrapeReleases(baseReleases, sites, type);

	return deepReleases;
}

async function fetchScenes(baseReleasesOrUrls) {
	return fetchReleases(baseReleasesOrUrls, 'scene');
}

async function fetchMovies(baseReleasesOrUrls) {
	return fetchReleases(baseReleasesOrUrls, 'movie');
}

module.exports = {
	fetchReleases,
	fetchScenes,
	fetchMovies,
};