added demo stats page (needs refinement)

src/lib/utils/stats.ts

@@ -0,0 +1,71 @@
+export interface UserStats {
+	totalSolves: number;
+	avgGuesses: number;
+	gradeDistribution: {
+		'S++': number;
+		'S+': number;
+		'A+': number;
+		'A': number;
+		'B+': number;
+		'B': number;
+		'C+': number;
+		'C': number;
+	};
+	currentStreak: number;
+	bestStreak: number;
+	recentCompletions: Array<{
+		date: string;
+		guessCount: number;
+		grade: string;
+	}>;
+}
+
+export function getGradeColor(grade: string): string {
+	switch (grade) {
+		case 'S++': return 'text-purple-600 bg-purple-100';
+		case 'S+': return 'text-yellow-600 bg-yellow-100';
+		case 'A+': return 'text-green-600 bg-green-100';
+		case 'A': return 'text-green-500 bg-green-50';
+		case 'B+': return 'text-blue-600 bg-blue-100';
+		case 'B': return 'text-blue-500 bg-blue-50';
+		case 'C+': return 'text-orange-600 bg-orange-100';
+		case 'C': return 'text-red-600 bg-red-100';
+		default: return 'text-gray-600 bg-gray-100';
+	}
+}
+
+export function formatDate(dateStr: string): string {
+	const date = new Date(dateStr + 'T00:00:00');
+	return date.toLocaleDateString('en-US', {
+		month: 'short',
+		day: 'numeric'
+	});
+}
+
+export function getStreakMessage(currentStreak: number): string {
+	if (currentStreak === 0) {
+		return "Start your streak today!";
+	} else if (currentStreak === 1) {
+		return "Keep it going!";
+	} else if (currentStreak < 7) {
+		return `${currentStreak} days strong!`;
+	} else if (currentStreak < 30) {
+		return `${currentStreak} day streak - amazing!`;
+	} else {
+		return `${currentStreak} days - you're unstoppable!`;
+	}
+}
+
+export function getPerformanceMessage(avgGuesses: number): string {
+	if (avgGuesses <= 2) {
+		return "Exceptional performance!";
+	} else if (avgGuesses <= 4) {
+		return "Great performance!";
+	} else if (avgGuesses <= 6) {
+		return "Good performance!";
+	} else if (avgGuesses <= 8) {
+		return "Room for improvement!";
+	} else {
+		return "Keep practicing!";
+	}
+}