gladiator inventory - fundamentals

function inventoryGladiator(input) {
    let inventory = input.shift().split(' ');

    for (let i = 0; i < input.length; i++) {
        let commands = input[i].split(' ');

        if (commands[0] === "Buy") {
            if (!inventory.includes(commands[1])) {
            inventory.push(commands[1]);
            }
        } else if (commands[0] === "Trash") {
            if (inventory.includes(commands[1])) {
                let index = inventory.indexOf(commands[1]);
                inventory.splice(index, 1);
            }
        } else if (commands[0] === "Repair") {
            if (inventory.includes(commands[1])) {
                let index = inventory.indexOf(commands[1]);
                inventory.splice(index, 1);
                inventory.push(commands[1]);
            }
        } else if (commands[0] === "Upgrade") {
            let upgadeElement = commands[1].split('-');
            if (inventory.includes(upgadeElement[0])) {
                let index = inventory.indexOf(upgadeElement[0]);
                inventory.splice(index + 1, 0, `${upgadeElement[0]}:${upgadeElement[1]}`);
            }
        }
    }
    console.log(inventory.join(' '));
}