/**
 * UI Management Module
 * Handles DOM updates, table rendering, and metric display
 */
class UIManager {
    constructor(calculator) {
        this.calculator = calculator;
    }

    updateSummaryMetrics() {
        try {
            const enabledResults = Object.values(this.calculator.results);
            if (enabledResults.length === 0) {
                this.setElementText('total-instances', '0');
                this.setElementText('total-revenue', 'CHF 0');
                this.setElementText('roi-percentage', '0%');
                this.setElementText('breakeven-time', 'N/A');
                return;
            }

            // Calculate averages across enabled scenarios
            const avgInstances = Math.round(enabledResults.reduce((sum, r) => sum + r.finalInstances, 0) / enabledResults.length);
            const avgRevenue = enabledResults.reduce((sum, r) => sum + r.totalRevenue, 0) / enabledResults.length;
            const avgROI = enabledResults.reduce((sum, r) => sum + r.roi, 0) / enabledResults.length;
            const avgBreakeven = enabledResults.filter(r => r.breakEvenMonth).reduce((sum, r) => sum + r.breakEvenMonth, 0) / enabledResults.filter(r => r.breakEvenMonth).length;

            this.setElementText('total-instances', avgInstances.toLocaleString());
            this.setElementText('total-revenue', this.formatCurrency(avgRevenue));
            this.setElementText('roi-percentage', this.formatPercentage(avgROI));
            this.setElementText('breakeven-time', isNaN(avgBreakeven) ? 'N/A' : `${Math.round(avgBreakeven)} months`);
        } catch (error) {
            console.error('Error updating summary metrics:', error);
        }
    }

    updateComparisonTable() {
        try {
            const tbody = document.getElementById('comparison-tbody');
            if (!tbody) {
                console.error('Comparison table body not found');
                return;
            }
            
            tbody.innerHTML = '';

            Object.values(this.calculator.results).forEach(result => {
                const modelLabel = result.investmentModel === 'loan' ? 
                    '<span class="badge bg-warning">Loan</span>' : 
                    '<span class="badge bg-success">Direct</span>';
                
                const row = tbody.insertRow();
                row.innerHTML = `
                    <td><strong>${result.scenario}</strong></td>
                    <td>${modelLabel}</td>
                    <td>${result.finalInstances.toLocaleString()}</td>
                    <td>${this.formatCurrencyDetailed(result.totalRevenue)}</td>
                    <td>${this.formatCurrencyDetailed(result.cspRevenue)}</td>
                    <td>${this.formatCurrencyDetailed(result.servalaRevenue)}</td>
                    <td class="${result.roi >= 0 ? 'text-success' : 'text-danger'}">${this.formatPercentage(result.roi)}</td>
                    <td>${result.breakEvenMonth ? result.breakEvenMonth + ' months' : 'N/A'}</td>
                `;
            });
        } catch (error) {
            console.error('Error updating comparison table:', error);
        }
    }

    updateMonthlyBreakdown() {
        try {
            const tbody = document.getElementById('monthly-tbody');
            if (!tbody) {
                console.error('Monthly breakdown table body not found');
                return;
            }
            
            tbody.innerHTML = '';

            // Combine all monthly data and sort by month and scenario
            const allData = [];
            Object.keys(this.calculator.monthlyData).forEach(scenario => {
                this.calculator.monthlyData[scenario].forEach(monthData => {
                    allData.push(monthData);
                });
            });

            allData.sort((a, b) => a.month - b.month || a.scenario.localeCompare(b.scenario));

            allData.forEach(data => {
                const row = tbody.insertRow();
                row.innerHTML = `
                    <td>${data.month}</td>
                    <td><span class="badge bg-secondary">${data.scenario}</span></td>
                    <td>${data.newInstances}</td>
                    <td>${data.churnedInstances}</td>
                    <td>${data.totalInstances.toLocaleString()}</td>
                    <td>${this.formatCurrencyDetailed(data.monthlyRevenue)}</td>
                    <td>${this.formatCurrencyDetailed(data.cspRevenue)}</td>
                    <td>${this.formatCurrencyDetailed(data.servalaRevenue)}</td>
                    <td>${this.formatCurrencyDetailed(data.cumulativeCSPRevenue)}</td>
                `;
            });
        } catch (error) {
            console.error('Error updating monthly breakdown:', error);
        }
    }

    setElementText(elementId, text) {
        const element = document.getElementById(elementId);
        if (element) {
            element.textContent = text;
        }
    }

    formatCurrency(amount) {
        try {
            // Use compact notation for large numbers in metric cards
            if (amount >= 1000000) {
                return new Intl.NumberFormat('de-CH', {
                    style: 'currency',
                    currency: 'CHF',
                    notation: 'compact',
                    minimumFractionDigits: 0,
                    maximumFractionDigits: 1
                }).format(amount);
            } else {
                return new Intl.NumberFormat('de-CH', {
                    style: 'currency',
                    currency: 'CHF',
                    minimumFractionDigits: 0,
                    maximumFractionDigits: 0
                }).format(amount);
            }
        } catch (error) {
            console.error('Error formatting currency:', error);
            return `CHF ${amount.toFixed(0)}`;
        }
    }

    formatCurrencyDetailed(amount) {
        try {
            // Use full formatting for detailed views (tables, exports)
            return new Intl.NumberFormat('de-CH', {
                style: 'currency',
                currency: 'CHF',
                minimumFractionDigits: 0,
                maximumFractionDigits: 0
            }).format(amount);
        } catch (error) {
            console.error('Error formatting detailed currency:', error);
            return `CHF ${amount.toFixed(0)}`;
        }
    }

    formatPercentage(value) {
        try {
            return new Intl.NumberFormat('de-CH', {
                style: 'percent',
                minimumFractionDigits: 1,
                maximumFractionDigits: 1
            }).format(value / 100);
        } catch (error) {
            console.error('Error formatting percentage:', error);
            return `${value.toFixed(1)}%`;
        }
    }
}