class ROICalculator {

    #smartboxes = {
        "MS5": new SmartBox('MS5', 9, null, 2199, "Base Station"),
        "MS5E18": new SmartBox('MS5E-18', 18, null, 1799, "Expansion Unit"),
        "MS5E42": new SmartBox('MS5E-42', 42, null, 2499, "Expansion Unit"),
    };

    #planPricing = {
        'Lite': { price: 828, name: 'Lite' },
        'Premium': { price: 1428, name: 'Premium' },
        'Business Pro': { price: 2028, name: 'Business Pro' }
    };

    #weeklyKeyAccesses;

    constructor(numKeys, weeklyKeyUsage, breakEvenTime, year3ROI, year5ROI, hardwareCost, hardwareList, softwarePlan, softwareCost){
        // inputs
        this.numKeys = numKeys;
        this.weeklyKeyUsage = weeklyKeyUsage;

        // outputs
        this.breakEvenTime = breakEvenTime;
        this.year3ROI = year3ROI;
        this.year5ROI = year5ROI;
        this.hardwareCost = hardwareCost;
        this.hardwareList = hardwareList;
        this.softwarePlan = softwarePlan;
        this.softwareCost = softwareCost;
    } // constructor

    getWeeklyKeyAccesses(){
        this.#weeklyKeyAccesses = this.numKeys * this.weeklyKeyUsage;
        return this.#weeklyKeyAccesses;
    }

    calculateHardwareCost(){
        let requiredCapacity = Math.ceil(this.numKeys);

        if (requiredCapacity <= 0) return { cost: 0, breakdown: [] };
        
        let totalCost = this.#smartboxes.MS5.price;
        let breakdown = { [this.#smartboxes.MS5.model]: 1 };
        let keysNeededFromExpansions = requiredCapacity - this.#smartboxes.MS5.bins;

        if (keysNeededFromExpansions > 0) {
            const MS5E42 = this.#smartboxes.MS5E42;
            const MS5E18 = this.#smartboxes.MS5E18;

            const MS5E42Quantity = Math.floor(keysNeededFromExpansions / MS5E42.bins);

            if (MS5E42Quantity > 0){
                totalCost += MS5E42Quantity * MS5E42.price;
                breakdown[MS5E42.model] = (breakdown[MS5E42.model] || 0) + MS5E42Quantity;
            } // if MS5E42Quantity > 0

            const remainder = keysNeededFromExpansions % MS5E42.bins;
            if (remainder > 0){
                if (remainder <= MS5E18.bins){
                    totalCost += MS5E18.price;
                    breakdown[MS5E18.model] = (breakdown[MS5E18.model] || 0) + 1;
                } else {
                    totalCost += MS5E42.price;
                    breakdown[MS5E42.model] = (breakdown[MS5E42.model] || 0) + 1;
                }
            } // if remainder

        } // if keysNeededFromExpansions > 0

        const breakdownText = Object.entries(breakdown).map(([name, count]) => `${count} x ${name}`);
        return {
            cost: totalCost,
            breakdown: breakdownText,
        };
    } // calculateHardwareCost()

    calculateSoftwareCost(selectedPlan="Premium") {
        this.softwareCost = this.#planPricing[selectedPlan]?.price || 0;
        return this.softwareCost;
    } // calculateSoftwareCost()

    formatCurrency(number){
        if (!isNaN(number)){
            return {
                amount: new Intl.NumberFormat('en-US', {
                            style: 'currency',
                            currency: 'USD'
                        }).format(number),
                isCurrency: true,
                raw: number
            }
        } else {
            return "N/A";
        }
    } // formatCurrency()

    round(value, decimals){
        const multiplier = Math.pow(10, decimals || 0);
        return Math.round(value * multiplier) / multiplier;
    } // round()

    fillForm(industry, outputForm){
        if (!outputForm) {
            throw new Error("fillForm: target form not found.");
        }
        const submit = outputForm.querySelector('input[type=submit');
        const existingInputs = outputForm.querySelectorAll(".roi-calculation-result");
        existingInputs.forEach((e) => {
            e.remove();
        });
        Object.keys(industry).forEach((key) => {
            const input = document.createElement("input");
            input.setAttribute("type", "hidden");
            input.setAttribute("id", key);
            input.setAttribute("name", key);
            input.classList.add("roi-calculation-result");
            if (Object.getPrototypeOf(industry[key]) === Object.prototype) {
                if (industry[key].isCurrency) input.setAttribute("value", industry[key].amount);
            } else {
                input.setAttribute("value", industry[key]);
            }
            outputForm.insertBefore(input, submit);
        });
    } // fillForm()
    
} // ROICalculator