import {ClimbingRouteRatingDB} from '../ClimbingRouteRating.db';
import {RouteRating} from './RouteRating.interface';

/**
 * Fetches and returns all ratings for the given route
 * @param route_id The id of the route to get the ratings for
 * @return Promise<RouteRating[]> The ratings
 */
export const findByRoute = async (route_id: string): Promise<RouteRating[]> => {
    let conn = ClimbingRouteRatingDB.getConnection();
    try {
        return await conn.query('SELECT rating_id, route_id, stars, timestamp FROM route_ratings WHERE route_id = ?', route_id);
    } catch (err) {
        throw err;
    }
};

/**
 * Get the median amount of stars the given route got from climbers
 * @param route_id The id of the route to get the rating for
 * @return number The median amount of stars with 1 fraction digit.
 */
export const getStarsForRoute = async (route_id: string): Promise<number> => {
    let ratings = await findByRoute(route_id);

    let starsSum = 0;
    let starsAmount = 0;

    for (let rating of ratings) {
        starsSum += rating.stars;
        starsAmount++;
    }

    return Number((starsSum / starsAmount).toFixed(1));
};

/**
 * Creates a new rating and returns the id
 * @param route_id The id of the route to be rated
 * @param stars The amount of stars to be given
 * @return number The id of the created rating
 */
export const createRating = async (route_id: string, stars: number): Promise<number> => {
    let conn = ClimbingRouteRatingDB.getConnection();
    try {
        let res = await conn.query('INSERT INTO route_ratings (route_id, stars) VALUES (?, ?) RETURNING rating_id', [route_id, stars]);

        return res[0].comment_id;
    } catch (err) {
        throw err;
    }
};