plant discovery

function plantDiscovery(input){
    let plantsObj = {};
    let discoveredPlants = Number(input.shift());
    for(let i = 0; i < discoveredPlants; i++) {
        let [plant, rarity] = input[i].split('<->');
        if(!plantsObj.hasOwnProperty(plant)) {
            plantsObj[plant] = {
                rarity: 0,
                rating: [],
            }
        }
        plantsObj[plant].rarity += Number(rarity);
    }
    let index = discoveredPlants;
    while(input[index] !== 'Exhibition') {
        let [action, ...data] = input[index].split(': ');
        switch (action) {
            case 'Rate':
                let [plant, rating] = data[0].split(' - ');
                if(plantsObj.hasOwnProperty(plant)) {
                    plantsObj[plant].rating.push(Number(rating));
                } else {
                    console.log("error");
                }
                break;
            case 'Update':
                let [plantName, newRarity] = data[0].split(' - ');
                if(plantsObj.hasOwnProperty(plantName)) {
                    plantsObj[plantName].rarity = Number(newRarity);
                } else {
                    console.log("error");
                }
                break;
            case 'Reset':
                let plantToReset = data[0];
                if(plantsObj.hasOwnProperty(plantToReset)) {
                    plantsObj[plantToReset].rating = [];
                } else {
                    console.log("error");
                }
                break;
        }
        index++;
    }
    console.log("Plants for the exhibition:");
    for(let key in plantsObj) {
        let totalGrades = plantsObj[key].rating.length;
        let average = 0;
        if(totalGrades !== 0) {
            plantsObj[key].rating = plantsObj[key].rating.reduce((a,b) => a+b);
            average = plantsObj[key].rating/totalGrades;
        }
        console.log(`- ${key}; Rarity: ${plantsObj[key].rarity}; Rating: ${average.toFixed(2)}`);
    }
}