`; const ctx = getElem('forecastChart').getContext('2d'); const labels = Array.from({ length: currentData.weeks + 1 }, (_, i) => `W${i}`); const chartData = { labels, datasets: currentData.results.slice(0, 4).map((p, i) => { const colors = ['#3B82F6', '#16A34A', '#F97316', '#9333EA']; return { label: p.name, data: p.history, borderColor: colors[i % colors.length], tension: 0.1, fill: false }; }) }; if (forecastChart) forecastChart.destroy(); forecastChart = new Chart(ctx, { type: 'line', data: chartData, options: { responsive: true, maintainAspectRatio: false } }); downloadSection.classList.remove('hidden'); showTab(1); }; generateBtn.addEventListener('click', generateForecast); // --- PDF DOWNLOAD --- const downloadPDF = () => { if (!currentData || !forecastChart) return; const { jsPDF } = window.jspdf; const pdf = new jsPDF({ orientation: 'portrait', unit: 'pt', format: 'a4' }); const btnText = getElem('pdf-btn-text'); const btnSpinner = getElem('pdf-btn-spinner'); btnText.classList.add('hidden'); btnSpinner.classList.remove('hidden'); downloadPdfBtn.disabled = true; try { const pageWidth = pdf.internal.pageSize.getWidth(); const margin = 40; let y = margin; pdf.setFont('helvetica', 'bold'); pdf.setFontSize(22); pdf.text("Inventory Forecast Report", pageWidth / 2, y, { align: 'center' }); y += 15; pdf.setFont('helvetica', 'normal'); pdf.setFontSize(10); pdf.text(`Forecast Period: ${currentData.weeks} Weeks | Report Date: ${today.toLocaleDateString('en-US')}`, pageWidth / 2, y, { align: 'center' }); y += 35; pdf.autoTable({ startY: y, theme: 'grid', head: [['Metric', 'Value']], body: [ ['High Risk Items (Stockout in <2 wks)', `${currentData.highRiskCount}`], ['Medium Risk Items (Stockout in <4 wks)', `${currentData.mediumRiskCount}`], ], didDrawPage: (data) => { y = data.cursor.y; } }); y += 20; pdf.setFont('helvetica', 'bold'); pdf.text("Forecast Summary", margin, y); y += 15; const tableData = currentData.results.map(p => [p.name, p.supplier, p.stockoutWeek !== -1 ? `Week ${p.stockoutWeek}` : 'None', p.risk]); pdf.autoTable({ startY: y, head: [['Product Name', 'Supplier', 'Estimated Stockout', 'Risk Level']], body: tableData, theme: 'striped', headStyles: { fillColor: [29, 78, 216] }, didParseCell: function (data) { if (data.section === 'body' && data.column.index === 3) { if (data.cell.raw === 'High') data.cell.styles.textColor = '#DC2626'; if (data.cell.raw === 'Medium') data.cell.styles.textColor = '#D97706'; } }, }); pdf.save(`Inventory-Forecast-Report.pdf`); } catch(e) { console.error("PDF Generation failed:", e); } finally { btnText.classList.remove('hidden'); btnSpinner.classList.remove('hidden'); downloadPdfBtn.disabled = false; } }; downloadPdfBtn.addEventListener('click', downloadPDF); initialize(); });