/**
 * Export Management Module
 * Handles PDF and CSV export functionality
 */
class ExportManager {
    constructor(calculator, uiManager) {
        this.calculator = calculator;
        this.uiManager = uiManager;
    }

    async exportToPDF() {
        // Check if jsPDF is available
        if (typeof window.jspdf === 'undefined') {
            alert('PDF export library is loading. Please try again in a moment.');
            return;
        }

        // Show model selection dialog
        const selectedModels = await this.showModelSelectionDialog();
        if (!selectedModels) {
            return; // User cancelled
        }

        try {
            const { jsPDF } = window.jspdf;
            const doc = new jsPDF('p', 'mm', 'a4');
            const pageWidth = doc.internal.pageSize.getWidth();
            const pageHeight = doc.internal.pageSize.getHeight();
            const margin = 20;
            
            // Store selected models for use throughout the export
            this.selectedModels = selectedModels;
            
            // Color scheme
            const colors = {
                primary: [0, 123, 255],
                success: [40, 167, 69],
                warning: [255, 193, 7],
                danger: [220, 53, 69],
                dark: [33, 37, 41],
                muted: [108, 117, 125]
            };

            let currentPage = 1;
            let yPos = 30;

            // Helper function to add new page with header/footer
            const addPage = () => {
                doc.addPage();
                currentPage++;
                yPos = 30;
                this.addPageHeader(doc, margin, colors);
            };

            // Helper function to check if we need a new page
            const checkPageBreak = (requiredSpace) => {
                if (yPos + requiredSpace > pageHeight - 30) {
                    addPage();
                }
            };

            // Title Page
            this.createTitlePage(doc, pageWidth, pageHeight, margin, colors);
            
            // Executive Summary Page
            addPage();
            yPos = this.createExecutiveSummary(doc, yPos, margin, colors);

            // Investment Parameters Page
            checkPageBreak(60);
            yPos = this.createParametersSection(doc, yPos, margin, colors);

            // Model Comparison Page
            checkPageBreak(80);
            yPos = this.createModelComparison(doc, yPos, margin, colors);

            // Charts Pages
            await this.addChartsToPDF(doc, colors, margin, addPage, checkPageBreak);

            // Detailed Results Table
            this.createDetailedResults(doc, colors, margin, addPage);

            // Add footers to all pages
            this.addFootersToAllPages(doc, currentPage, colors);

            // Save the PDF
            const filename = `servala-roi-investment-analysis-${new Date().toISOString().split('T')[0]}.pdf`;
            doc.save(filename);

        } catch (error) {
            console.error('PDF Export Error:', error);
            alert('An error occurred while generating the PDF. Please try again or export as CSV instead.');
        }
    }

    createTitlePage(doc, pageWidth, pageHeight, margin, colors) {
        // Background design element
        doc.setFillColor(...colors.primary);
        doc.rect(0, 0, pageWidth, 60, 'F');
        
        // White title text
        doc.setTextColor(255, 255, 255);
        doc.setFontSize(28);
        doc.setFont('helvetica', 'bold');
        doc.text('Investment Analysis Report', pageWidth/2, 35, { align: 'center' });
        
        // Subtitle
        doc.setFontSize(14);
        doc.setFont('helvetica', 'normal');
        doc.text('CSP Partnership ROI Calculator', pageWidth/2, 45, { align: 'center' });

        // Company section
        doc.setTextColor(...colors.dark);
        doc.setFontSize(20);
        doc.setFont('helvetica', 'bold');
        doc.text('Servala Partnership Opportunity', pageWidth/2, 90, { align: 'center' });

        // Investment summary box
        const inputs = this.calculator.getInputValues();
        const boxY = 110;
        const boxHeight = 40;
        
        doc.setFillColor(248, 249, 250);
        doc.roundedRect(margin, boxY, pageWidth - 2*margin, boxHeight, 3, 3, 'F');
        doc.setDrawColor(...colors.muted);
        doc.roundedRect(margin, boxY, pageWidth - 2*margin, boxHeight, 3, 3, 'S');

        doc.setFontSize(16);
        doc.setTextColor(...colors.primary);
        doc.text('Investment Overview', pageWidth/2, boxY + 12, { align: 'center' });
        
        doc.setFontSize(12);
        doc.setTextColor(...colors.dark);
        doc.text(`Investment Amount: ${this.formatCurrency(inputs.investmentAmount)}`, pageWidth/2, boxY + 22, { align: 'center' });
        doc.text(`Analysis Period: ${inputs.timeframe} years`, pageWidth/2, boxY + 32, { align: 'center' });

        // Generated date
        doc.setFontSize(10);
        doc.setTextColor(...colors.muted);
        const currentDate = new Date().toLocaleDateString('en-US', {
            year: 'numeric',
            month: 'long',
            day: 'numeric'
        });
        doc.text(`Generated on: ${currentDate}`, pageWidth/2, pageHeight - 30, { align: 'center' });
    }

    addPageHeader(doc, margin, colors) {
        doc.setFillColor(...colors.primary);
        doc.rect(0, 0, doc.internal.pageSize.getWidth(), 15, 'F');
        doc.setTextColor(255, 255, 255);
        doc.setFontSize(10);
        doc.setFont('helvetica', 'bold');
        doc.text('Servala CSP Investment Analysis', margin, 10);
    }

    createExecutiveSummary(doc, yPos, margin, colors) {
        doc.setFontSize(18);
        doc.setTextColor(...colors.primary);
        doc.setFont('helvetica', 'bold');
        doc.text('Executive Summary', margin, yPos);
        yPos += 15;

        const enabledResults = Object.values(this.calculator.results);
        const directResults = enabledResults.filter(r => r.investmentModel === 'direct' && this.selectedModels.direct);
        const loanResults = enabledResults.filter(r => r.investmentModel === 'loan' && this.selectedModels.loan);
        
        doc.setFontSize(11);
        doc.setTextColor(...colors.dark);
        doc.setFont('helvetica', 'normal');
        
        // Investment models comparison
        if (directResults.length > 0 && loanResults.length > 0) {
            const avgDirectROI = directResults.reduce((sum, r) => sum + r.roi, 0) / directResults.length;
            const avgLoanROI = loanResults.reduce((sum, r) => sum + r.roi, 0) / loanResults.length;
            const avgDirectNetPos = directResults.reduce((sum, r) => sum + r.netPosition, 0) / directResults.length;
            const avgLoanNetPos = loanResults.reduce((sum, r) => sum + r.netPosition, 0) / loanResults.length;
            
            doc.text('This analysis compares two investment models across multiple growth scenarios:', margin, yPos);
            yPos += 10;
            
            // Direct Investment Summary
            doc.setFillColor(40, 167, 69, 0.1); // Success color with opacity
            doc.roundedRect(margin, yPos, (doc.internal.pageSize.getWidth() - 3*margin)/2, 35, 2, 2, 'F');
            
            doc.setTextColor(...colors.success);
            doc.setFont('helvetica', 'bold');
            doc.text('Direct Investment Model', margin + 5, yPos + 8);
            
            doc.setTextColor(...colors.dark);
            doc.setFont('helvetica', 'normal');
            doc.setFontSize(10);
            doc.text(`Average ROI: ${this.uiManager.formatPercentage(avgDirectROI)}`, margin + 5, yPos + 16);
            doc.text(`Average Net Profit: ${this.formatCurrency(avgDirectNetPos)}`, margin + 5, yPos + 24);
            doc.text('Performance-based with bonuses', margin + 5, yPos + 32);
            
            // Loan Model Summary
            const loanBoxX = margin + (doc.internal.pageSize.getWidth() - 3*margin)/2 + 10;
            doc.setFillColor(255, 193, 7, 0.1); // Warning color with opacity
            doc.roundedRect(loanBoxX, yPos, (doc.internal.pageSize.getWidth() - 3*margin)/2, 35, 2, 2, 'F');
            
            doc.setTextColor(...colors.warning);
            doc.setFont('helvetica', 'bold');
            doc.setFontSize(11);
            doc.text('Loan Model', loanBoxX + 5, yPos + 8);
            
            doc.setTextColor(...colors.dark);
            doc.setFont('helvetica', 'normal');
            doc.setFontSize(10);
            doc.text(`Average ROI: ${this.uiManager.formatPercentage(avgLoanROI)}`, loanBoxX + 5, yPos + 16);
            doc.text(`Average Net Profit: ${this.formatCurrency(avgLoanNetPos)}`, loanBoxX + 5, yPos + 24);
            doc.text('Fixed returns, guaranteed', loanBoxX + 5, yPos + 32);
            
            yPos += 45;
        }
        
        return yPos;
    }

    createParametersSection(doc, yPos, margin, colors) {
        doc.setFontSize(16);
        doc.setTextColor(...colors.primary);
        doc.setFont('helvetica', 'bold');
        doc.text('Investment Parameters', margin, yPos);
        yPos += 15;

        const inputs = this.calculator.getInputValues();
        
        // Create parameter table
        const params = [
            ['Investment Amount', this.formatCurrency(inputs.investmentAmount)],
            ['Investment Timeframe', `${inputs.timeframe} years`],
            ['Service Revenue per Instance', `${this.formatCurrency(inputs.revenuePerInstance)} / month`],
            ['Core Service Revenue per Instance', `${this.formatCurrency(inputs.coreServiceRevenue)} / month`],
            ['Total Revenue per Instance', `${this.formatCurrency(inputs.revenuePerInstance + inputs.coreServiceRevenue)} / month`],
            ['Loan Interest Rate', `${(inputs.loanInterestRate * 100).toFixed(1)}%`],
            ['Direct Investment Share', `${(inputs.servalaShare * 100).toFixed(0)}% to Servala`],
            ['Grace Period', `${inputs.gracePeriod} months`]
        ];

        doc.setFontSize(11);
        params.forEach(([label, value]) => {
            doc.setTextColor(...colors.dark);
            doc.setFont('helvetica', 'normal');
            doc.text(label + ':', margin + 5, yPos);
            doc.setFont('helvetica', 'bold');
            doc.text(value, margin + 80, yPos);
            yPos += 8;
        });

        return yPos + 10;
    }

    createModelComparison(doc, yPos, margin, colors) {
        doc.setFontSize(16);
        doc.setTextColor(...colors.primary);
        doc.setFont('helvetica', 'bold');
        doc.text('Investment Model Comparison', margin, yPos);
        yPos += 15;

        // Create comparison table
        const scenarios = ['Conservative', 'Moderate', 'Aggressive'];
        const tableData = [];
        
        scenarios.forEach(scenarioName => {
            const directResult = Object.values(this.calculator.results)
                .find(r => r.scenario === scenarioName && r.investmentModel === 'direct');
            const loanResult = Object.values(this.calculator.results)
                .find(r => r.scenario === scenarioName && r.investmentModel === 'loan');
            
            if (directResult && loanResult) {
                tableData.push([
                    scenarioName,
                    this.formatCurrency(directResult.netPosition),
                    this.uiManager.formatPercentage(directResult.roi),
                    this.formatCurrency(loanResult.netPosition),
                    this.uiManager.formatPercentage(loanResult.roi)
                ]);
            }
        });

        // Table headers
        const headers = ['Scenario', 'Direct Net Profit', 'Direct ROI', 'Loan Net Profit', 'Loan ROI'];
        const colWidths = [30, 35, 25, 35, 25];
        
        // Draw table
        this.drawTable(doc, margin, yPos, headers, tableData, colWidths, colors);
        
        return yPos + (tableData.length + 2) * 8;
    }

    async addChartsToPDF(doc, colors, margin, addPage, checkPageBreak) {
        // Add charts by capturing them as images
        const chartIds = ['instanceGrowthChart', 'revenueChart', 'cashFlowChart', 'modelComparisonChart'];
        const chartTitles = [
            'ROI Progression Over Time',
            'Net Financial Position',
            'Performance Comparison',
            'Investment Model Comparison'
        ];

        for (let i = 0; i < chartIds.length; i++) {
            checkPageBreak(120);
            
            const canvas = document.getElementById(chartIds[i]);
            if (canvas) {
                // Add chart title
                doc.setFontSize(14);
                doc.setTextColor(...colors.primary);
                doc.setFont('helvetica', 'bold');
                doc.text(chartTitles[i], margin, doc.internal.pageSize.getHeight() - 250);
                
                // Capture chart as image
                const imgData = canvas.toDataURL('image/png', 1.0);
                doc.addImage(imgData, 'PNG', margin, doc.internal.pageSize.getHeight() - 240, 
                    doc.internal.pageSize.getWidth() - 2*margin, 100);
                
                if (i < chartIds.length - 1) addPage();
            }
        }
    }

    createDetailedResults(doc, colors, margin, addPage) {
        addPage();
        let yPos = 30;
        
        doc.setFontSize(16);
        doc.setTextColor(...colors.primary);
        doc.setFont('helvetica', 'bold');
        doc.text('Detailed Financial Results', margin, yPos);
        yPos += 15;

        // Create detailed results table
        const headers = ['Scenario', 'Model', 'Net Profit', 'ROI', 'Break-even'];
        const colWidths = [35, 25, 35, 25, 30];
        const tableData = [];
        
        Object.values(this.calculator.results).forEach(result => {
            tableData.push([
                result.scenario,
                result.investmentModel === 'direct' ? 'Direct' : 'Loan',
                this.formatCurrency(result.netPosition),
                this.uiManager.formatPercentage(result.roi),
                result.breakEvenMonth ? `${result.breakEvenMonth} months` : 'N/A'
            ]);
        });

        this.drawTable(doc, margin, yPos, headers, tableData, colWidths, colors);
    }

    drawTable(doc, x, y, headers, data, colWidths, colors) {
        const rowHeight = 8;
        const startX = x;
        let currentY = y;
        
        // Draw headers
        doc.setFillColor(...colors.primary);
        doc.rect(startX, currentY - 6, colWidths.reduce((sum, w) => sum + w, 0), rowHeight, 'F');
        
        doc.setTextColor(255, 255, 255);
        doc.setFont('helvetica', 'bold');
        doc.setFontSize(10);
        
        let currentX = startX;
        headers.forEach((header, i) => {
            doc.text(header, currentX + 2, currentY - 1);
            currentX += colWidths[i];
        });
        
        currentY += rowHeight;
        
        // Draw data rows
        doc.setTextColor(...colors.dark);
        doc.setFont('helvetica', 'normal');
        
        data.forEach((row, rowIndex) => {
            if (rowIndex % 2 === 1) {
                doc.setFillColor(248, 249, 250);
                doc.rect(startX, currentY - 6, colWidths.reduce((sum, w) => sum + w, 0), rowHeight, 'F');
            }
            
            currentX = startX;
            row.forEach((cell, i) => {
                doc.text(String(cell), currentX + 2, currentY - 1);
                currentX += colWidths[i];
            });
            
            currentY += rowHeight;
        });
        
        // Draw table border
        doc.setDrawColor(...colors.muted);
        doc.rect(startX, y - 6, colWidths.reduce((sum, w) => sum + w, 0), (data.length + 1) * rowHeight, 'S');
    }

    addFootersToAllPages(doc, totalPages, colors) {
        for (let i = 1; i <= totalPages; i++) {
            doc.setPage(i);
            const pageHeight = doc.internal.pageSize.getHeight();
            const pageWidth = doc.internal.pageSize.getWidth();
            
            doc.setFontSize(8);
            doc.setTextColor(...colors.muted);
            doc.text(`Page ${i} of ${totalPages}`, pageWidth - 30, pageHeight - 10);
            doc.text('Generated by Servala CSP ROI Calculator', 20, pageHeight - 10);
            
            // Add a line above footer
            doc.setDrawColor(...colors.muted);
            doc.line(20, pageHeight - 15, pageWidth - 20, pageHeight - 15);
        }
    }

    async showModelSelectionDialog() {
        return new Promise((resolve) => {
            // Create modal dialog
            const modal = document.createElement('div');
            modal.style.cssText = `
                position: fixed;
                top: 0;
                left: 0;
                width: 100%;
                height: 100%;
                background: rgba(0, 0, 0, 0.5);
                display: flex;
                justify-content: center;
                align-items: center;
                z-index: 10000;
            `;
            
            const dialog = document.createElement('div');
            dialog.style.cssText = `
                background: white;
                padding: 2rem;
                border-radius: 8px;
                box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
                max-width: 400px;
                width: 90%;
            `;
            
            dialog.innerHTML = `
                <h5 style="margin-bottom: 1rem; color: #007bff;">Select Investment Models for PDF</h5>
                <p style="margin-bottom: 1.5rem; color: #6c757d;">Choose which models to include in your PDF report:</p>
                
                <div style="margin-bottom: 1rem;">
                    <label style="display: flex; align-items: center; margin-bottom: 0.5rem; cursor: pointer;">
                        <input type="checkbox" id="pdf-direct-model" checked style="margin-right: 0.5rem;">
                        <span style="color: #28a745; font-weight: bold;">Direct Investment Model</span>
                    </label>
                    <small style="color: #6c757d; margin-left: 1.5rem;">Performance-based revenue sharing with scaling bonuses</small>
                </div>
                
                <div style="margin-bottom: 2rem;">
                    <label style="display: flex; align-items: center; margin-bottom: 0.5rem; cursor: pointer;">
                        <input type="checkbox" id="pdf-loan-model" checked style="margin-right: 0.5rem;">
                        <span style="color: #ffc107; font-weight: bold;">Loan Model</span>
                    </label>
                    <small style="color: #6c757d; margin-left: 1.5rem;">Fixed interest lending with guaranteed returns</small>
                </div>
                
                <div style="display: flex; gap: 1rem; justify-content: flex-end;">
                    <button id="pdf-cancel-btn" style="padding: 0.5rem 1rem; border: 1px solid #ccc; background: white; border-radius: 4px; cursor: pointer;">Cancel</button>
                    <button id="pdf-export-btn" style="padding: 0.5rem 1rem; border: none; background: #007bff; color: white; border-radius: 4px; cursor: pointer;">Export PDF</button>
                </div>
            `;
            
            modal.appendChild(dialog);
            document.body.appendChild(modal);
            
            // Handle button clicks
            document.getElementById('pdf-cancel-btn').addEventListener('click', () => {
                document.body.removeChild(modal);
                resolve(null);
            });
            
            document.getElementById('pdf-export-btn').addEventListener('click', () => {
                const directSelected = document.getElementById('pdf-direct-model').checked;
                const loanSelected = document.getElementById('pdf-loan-model').checked;
                
                if (!directSelected && !loanSelected) {
                    alert('Please select at least one investment model.');
                    return;
                }
                
                document.body.removeChild(modal);
                resolve({
                    direct: directSelected,
                    loan: loanSelected
                });
            });
            
            // Close on background click
            modal.addEventListener('click', (e) => {
                if (e.target === modal) {
                    document.body.removeChild(modal);
                    resolve(null);
                }
            });
        });
    }

    formatCurrency(amount) {
        try {
            // Get current currency from the page
            const currencyElement = document.getElementById('currency');
            const currency = currencyElement ? currencyElement.value : 'CHF';
            
            // Determine locale based on currency
            const locale = currency === 'EUR' ? 'de-DE' : 'de-CH';
            
            // Consistent currency formatting: currency in front, no decimals for whole numbers
            return new Intl.NumberFormat(locale, {
                style: 'currency',
                currency: currency,
                minimumFractionDigits: 0,
                maximumFractionDigits: 0
            }).format(amount);
        } catch (error) {
            console.error('Error formatting currency:', error);
            return `CHF ${Math.round(amount).toLocaleString()}`;
        }
    }

    exportToCSV() {
        try {
            // Create comprehensive CSV with summary and detailed data
            let csvContent = 'CSP ROI Calculator Export\n';
            csvContent += `Generated on: ${new Date().toLocaleDateString()}\n\n`;

            // Add input parameters
            csvContent += 'INPUT PARAMETERS\n';
            const inputs = this.calculator.getInputValues();
            csvContent += `Currency,${inputs.currency}\n`;
            csvContent += `Investment Amount,${inputs.investmentAmount}\n`;
            csvContent += `Timeframe (years),${inputs.timeframe}\n`;
            csvContent += `Investment Model,${inputs.investmentModel === 'loan' ? 'Loan Model' : 'Direct Investment'}\n`;
            if (inputs.investmentModel === 'loan') {
                csvContent += `Loan Interest Rate (%),${(inputs.loanInterestRate * 100).toFixed(1)}\n`;
            }
            csvContent += `Service Revenue per Instance (${inputs.currency}),${inputs.revenuePerInstance}\n`;
            csvContent += `Core Service Revenue per Instance (${inputs.currency}),${inputs.coreServiceRevenue}\n`;
            csvContent += `Total Revenue per Instance (${inputs.currency}),${inputs.revenuePerInstance + inputs.coreServiceRevenue}\n`;
            if (inputs.investmentModel === 'direct') {
                csvContent += `Servala Share (%),${(inputs.servalaShare * 100).toFixed(0)}\n`;
                csvContent += `Grace Period (months),${inputs.gracePeriod}\n`;
            }
            csvContent += '\n';

            // Add scenario summary
            csvContent += 'SCENARIO SUMMARY\n';
            csvContent += `Scenario,Investment Model,Final Instances,Total Revenue (${inputs.currency}),CSP Revenue (${inputs.currency}),Servala Revenue (${inputs.currency}),ROI (%),Break-even (months)\n`;

            Object.values(this.calculator.results).forEach(result => {
                const modelText = result.investmentModel === 'loan' ? 'Loan' : 'Direct';
                csvContent += `${result.scenario},${modelText},${result.finalInstances},${result.totalRevenue.toFixed(2)},${result.cspRevenue.toFixed(2)},${result.servalaRevenue.toFixed(2)},${result.roi.toFixed(2)},${result.breakEvenMonth || 'N/A'}\n`;
            });

            csvContent += '\n';

            // Add detailed monthly data
            csvContent += 'MONTHLY BREAKDOWN\n';
            csvContent += `Month,Scenario,New Instances,Churned Instances,Total Instances,Service Revenue (${inputs.currency}),Core Revenue (${inputs.currency}),Total Revenue (${inputs.currency}),CSP Revenue (${inputs.currency}),Servala Revenue (${inputs.currency}),Cumulative CSP Revenue (${inputs.currency}),Cumulative Servala Revenue (${inputs.currency})\n`;

            // Combine all monthly data
            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 => {
                csvContent += `${data.month},${data.scenario},${data.newInstances},${data.churnedInstances},${data.totalInstances},${(data.serviceRevenue || data.monthlyRevenue || 0).toFixed(2)},${(data.coreRevenue || 0).toFixed(2)},${(data.totalRevenue || data.monthlyRevenue || 0).toFixed(2)},${data.cspRevenue.toFixed(2)},${data.servalaRevenue.toFixed(2)},${data.cumulativeCSPRevenue.toFixed(2)},${data.cumulativeServalaRevenue.toFixed(2)}\n`;
            });

            // Create and download file
            const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
            const link = document.createElement('a');
            const url = URL.createObjectURL(blob);
            link.setAttribute('href', url);

            const filename = `servala-csp-roi-data-${new Date().toISOString().split('T')[0]}.csv`;
            link.setAttribute('download', filename);
            link.style.visibility = 'hidden';

            document.body.appendChild(link);
            link.click();
            document.body.removeChild(link);

            // Clean up
            URL.revokeObjectURL(url);

        } catch (error) {
            console.error('CSV Export Error:', error);
            alert('An error occurred while generating the CSV file. Please try again.');
        }
    }
}