'use strict';

const knex = require('./knex');

async function curateTag(tag) {
    const aliases = await knex('tags').where({ alias_for: tag.id });

    return {
        id: tag.id,
        name: tag.name,
        description: tag.description,
        group: {
            id: tag.group_id,
            name: tag.group_name,
            description: tag.group_description,
            slug: tag.group_slug,
        },
        aliases: aliases.map(({ name }) => name),
    };
}

function curateTags(tags) {
    return Promise.all(tags.map(async tag => curateTag(tag)));
}

async function storeTags(release, releaseEntry) {
    return knex('tags_associated').insert(release.tags.map(tagId => ({
        tag_id: tagId,
        release_id: releaseEntry.id,
    })));
}

async function fetchTags(tagId, tagSlug) {
    const tags = await knex('tags')
        .where({ 'tags.id': tagId })
        .orWhere({ 'tags.slug': tagSlug })
        .andWhere({ 'tags.alias_for': null })
        .select(
            'tags.*',
            'tags_groups.id as group_id', 'tags_groups.name as group_name', 'tags_groups.slug as group_slug', 'tags_groups.description as groups_description',
        )
        .leftJoin('tags_groups', 'tags.group_id', 'tags_groups.id')
        .limit(100);

    return curateTags(tags);
}

async function matchTags(rawTags) {
    const tags = rawTags
        .concat(rawTags.map(tag => tag.toLowerCase()))
        .concat(rawTags.map(tag => tag.toUpperCase()));

    const tagEntries = await knex('tags')
        .pluck('aliases.id')
        .whereIn('tags.name', tags)
        .where(function where() {
            this
                .whereNull('tags.alias_for')
                .orWhereNull('aliases.alias_for');
        })
        .join('tags as aliases', function join() {
            this
                .on('tags.alias_for', 'aliases.id')
                .orOn('tags.id', 'aliases.id');
        })
        .groupBy('aliases.id');

    return tagEntries;
}

module.exports = {
    storeTags,
    fetchTags,
    matchTags,
};