'use strict';

const config = require('config');

const logger = require('./logger')(__filename);
const argv = require('./argv');
const knex = require('./knex');
const whereOr = require('./utils/where-or');

function curateEntity(entity, includeParameters = false) {
	const curatedEntity = {
		id: entity.id,
		name: entity.name,
		url: entity.url,
		description: entity.description,
		slug: entity.slug,
		type: entity.type,
		parameters: includeParameters ? entity.parameters : null,
		parent: entity.parent_id && entity.parent,
		children: (entity.children || []).map(child => curateEntity({
			...child,
			parent: entity,
		}, includeParameters)),
	};

	return curatedEntity;
}

async function curateEntities(entities, includeParameters) {
	return Promise.all(entities.map(async entity => curateEntity(entity, includeParameters)));
}

async function fetchChannelsFromArgv() {
	const rawNetworks = await knex.raw(`
		/* networks from argument with channels as children */
		WITH RECURSIVE children AS (
			SELECT
				id, parent_id, name, slug, type, url, description, parameters
			FROM
				entities
			WHERE
				slug = ANY(?) AND entities.type = 'network'
			UNION ALL
			SELECT
				entities.id, entities.parent_id, entities.name, entities.slug, entities.type, entities.url, entities.description, entities.parameters
			FROM
				entities
			INNER JOIN
				children ON children.id = entities.parent_id
		)
		SELECT
			entities.*, row_to_json(parents) as parent, json_agg(children) as children
		FROM
			children
		LEFT JOIN
			entities ON entities.id = children.parent_id
		LEFT JOIN
			entities AS parents ON parents.id = entities.parent_id
		WHERE
			children.type = 'channel'
		GROUP BY
			children.parent_id, entities.id, entities.name, parents.id

		UNION ALL

		/* channels from argument as the child of network with parent */
		SELECT
			entities.*, row_to_json(parents) as parent, json_agg(row_to_json(children))
		FROM
			entities AS children
		LEFT JOIN
			entities ON entities.id = children.parent_id
		LEFT JOIN
			entities AS parents ON parents.id = entities.parent_id
		WHERE
			children.slug = ANY(?) AND children.type = 'channel'
		GROUP BY
			entities.id, parents.id;
	`, [argv.networks || [], argv.channels || []]);

	const curatedNetworks = await curateEntities(rawNetworks.rows, true);
	logger.info(`Found ${curatedNetworks.length} networks in database`);

	return curatedNetworks;
}

async function fetchChannelsFromConfig() {
	const rawSites = await knex('entities')
		.select(knex.raw('entities.*, row_to_json(parents) as parent'))
		.leftJoin('entities as parents', 'parents.id', 'entities.parent_id')
		.where((builder) => {
			if (config.include) {
				builder.whereIn('entities.slug', config.include);
			}
		})
		.whereNot((builder) => {
			builder.whereIn('entities.slug', config.exclude || []);
		});

	const curatedSites = await curateEntities(rawSites, true);
	logger.info(`Found ${curatedSites.length} entities in database`);

	return curatedSites;
}

async function fetchIncludedEntities() {
	if (argv.networks || argv.channels) {
		return fetchChannelsFromArgv();
	}

	return fetchChannelsFromConfig();
}

async function fetchChannels(queryObject) {
	const sites = await knex('sites')
		.where(builder => whereOr(queryObject, 'sites', builder))
		.select(
			'sites.*',
			'networks.name as network_name', 'networks.slug as network_slug', 'networks.url as network_url', 'networks.description as network_description', 'networks.parameters as network_parameters',
		)
		.leftJoin('networks', 'sites.network_id', 'networks.id')
		.limit(100);

	return curateEntities(sites);
}

async function fetchChannelsFromReleases() {
	const sites = await knex('releases')
		.select('site_id', '')
		.leftJoin('sites', 'sites.id', 'releases.site_id')
		.groupBy('sites.id')
		.limit(100);

	return curateEntities(sites);
}

module.exports = {
	curateEntity,
	curateEntities,
	fetchIncludedEntities,
	fetchChannels,
	fetchChannelsFromConfig,
	fetchChannelsFromArgv,
	fetchChannelsFromReleases,
};