class Vacation{
    constructor(organizer, destination, budget){
        this.organizer = organizer;
        this.destination = destination;
        this.budget = budget;
        this.kids = {};
    }

    registerChild(name, grade, budget){
        if(budget < this.budget){
            return `${name}'s money is not enough to go on vacation to ${this.destination}.`
        }
        if(this.kids.hasOwnProperty(grade)){
            for (const kid of this.kids[grade]) {
                if (kid === `${name}-${budget}`) {
                    return `${name} is already in the list for this ${this.destination} vacation.`
                }
            }
            this.kids[grade].push(`${name}-${budget}`);
        }else{
            this.kids[grade] = [];
            this.kids[grade].push(`${name}-${budget}`);
        }
         return this.kids[grade];
    }

    removeChild(name,grade){
        if(this.kids.hasOwnProperty(grade)){
            for (const kid of this.kids[grade]) {
                let kidInfo = kid.split('-');
                let kidName = kidInfo[0];
                if(kidName === name){
                    let index = this.kids[grade].indexOf(kid);
                    this.kids[grade].splice(index,1);
                    return this.kids[grade];
                }
            }
        }else{
           return `'We couldn't find ${name} in ${grade} grade.`
        }
    }

    toString(){
        if(this.numberOfChildren === 0){
            return `No children are enrolled for the trip and the organization of ${this.organizer} falls out...`;
        }
        let result = `${this.organizer} will take ${this.numberOfChildren} children on trip to ${this.destination}\n`;

        Object.entries(this.kids).sort((a,b)=>a[0]-b[0]);

        for (const grade in this.kids) {
            result+=`Grade: ${grade}\n`;
            let currentNumber = 1;

            for (const kid of this.kids[grade]) {
                result+=`${currentNumber}. ${kid}\n`;
                currentNumber++;
            }
        }
        return result;
    }

    get numberOfChildren(){
        this._numberOfChildren = 0;
        for (const grade in this.kids) {
            this._numberOfChildren+=this.kids[grade].length;
        }
        return this._numberOfChildren;
    }
}