Canvas Assignment Assistant

// Helper function for date formatting and validation export function formatDate(dateStr: string | null, format: 'full' | 'date-only' = 'full'): string { if (!dateStr) return 'No date set'; try { const date = new Date(dateStr); if (isNaN(date.getTime())) return 'Invalid date'; if (format === 'date-only') { return date.toLocaleDateString(undefined, { year: 'numeric', month: '2-digit', day: '2-digit' }); } return date.toLocaleString(undefined, { year: 'numeric', month: '2-digit', day: '2-digit', hour: '2-digit', minute: '2-digit', timeZoneName: 'short' }); } catch (error) { return 'Invalid date'; } } // Helper function to parse and validate date strings export function parseDate(dateStr: string | null): Date | null { if (!dateStr) return null; try { // If the date string is just YYYY-MM-DD, treat it as local timezone if (dateStr.match(/^\d{4}-\d{2}-\d{2}$/)) { const [year, month, day] = dateStr.split('-').map(Number); const date = new Date(year, month - 1, day); return isNaN(date.getTime()) ? null : date; } // Otherwise parse as ISO string const date = new Date(dateStr); return isNaN(date.getTime()) ? null : date; } catch { return null; } } // Helper function to check if a date is within a range export function isDateInRange(date: string | null, before?: string, after?: string): boolean { if (!date) return true; // Include assignments with no due date const dueDate = parseDate(date); if (!dueDate) return true; // Include if date parsing fails if (before) { const beforeDate = parseDate(before); if (beforeDate) { // Set to end of day (23:59:59.999) in local timezone beforeDate.setHours(23, 59, 59, 999); if (dueDate.getTime() > beforeDate.getTime()) return false; } } if (after) { const afterDate = parseDate(after); if (afterDate) { // Set to start of day (00:00:00.000) in local timezone afterDate.setHours(0, 0, 0, 0); if (dueDate.getTime() < afterDate.getTime()) return false; } } return true; }