@cycxllin/cmpt315-a2/winnersObject.js

Fulfills CMPT 315 Assignment 2, MacEwan University Winter 2024.

/*
Takes array of matches and returns an object which lists each participant
    and a list of who they've beaten.
Requires: participants.js (function which creates a list of participants)
Parameters: array of matches where each match is a dictionary containing the
    following key: values
        winner: string
        loser: string
        loser-points: number
Returns: Object consisting of strings of winners (as key) with list of strings of who 
    they have beaten (as value)
*/

const participants = require('./participants.js');

function winnersObject(matches) {
    if (Array.isArray(matches)){
        const winners = {};

        // make list of players and add to winners object as keys
        players = participants(matches);

        players.forEach(player => {
            winners[player] = [];
        });

        // add each loser to appropriate winner if not already there
        matches.forEach(match =>{
            let winner = match.winner;
            let loser = match.loser;

            if (winner != undefined && loser != undefined){
                if (!winners[winner].includes(loser)){
                    // add loser to list of players winner has beat
                    winners[winner].push(loser);
                }
            }
        });
    
        return winners;

    } else {
        console.error("Error: Parameter passed is not an array");
        return -1;
    }
}

module.exports = participants;