feat: Implement cumulative XP leveling system with new helper functions and update XP bar to show progress within the current level.

src/graphics/studentID.ts

@@ -97,9 +97,12 @@ export async function generateStudentIdCard(data: StudentCardData): Promise<Buff
     ctx.restore();
 
     // Draw XP Bar
-    const xpForNextLevel = levelingService.getXpForLevel(data.level);
+    const xpForThisLevel = levelingService.getXpForNextLevel(data.level); // The total size of the current level bucket
+    const xpAtStartOfLevel = levelingService.getXpToReachLevel(data.level); // The accumulated XP when this level started
+    const currentLevelProgress = Number(data.xp) - xpAtStartOfLevel; // How much XP into this level
+
     const xpBarMaxWidth = 382;
-    const xpBarWidth = xpBarMaxWidth * Number(data.xp) / Number(xpForNextLevel);
+    const xpBarWidth = Math.max(0, Math.min(xpBarMaxWidth, xpBarMaxWidth * currentLevelProgress / xpForThisLevel));
     const xpBarHeight = 3;
     ctx.save();
     ctx.fillStyle = '#B3AD93';

src/modules/leveling/leveling.service.ts

@@ -5,12 +5,42 @@ import { config } from "@/lib/config";
 import type { Transaction } from "@/lib/types";
 
 export const levelingService = {
-    // Calculate XP required for a specific level
-    getXpForLevel: (level: number) => {
-        return Math.floor(config.leveling.base * Math.pow(level, config.leveling.exponent));
+    // Calculate total XP required to REACH a specific level (Cumulative)
+    // Level 1 = 0 XP
+    // Level 2 = Base * (1^Exp)
+    // Level 3 = Level 2 + Base * (2^Exp)
+    // ...
+    getXpToReachLevel: (level: number) => {
+        let total = 0;
+        for (let l = 1; l < level; l++) {
+            total += Math.floor(config.leveling.base * Math.pow(l, config.leveling.exponent));
+        }
+        return total;
     },
 
-    // Pure XP addition - No cooldown checks
+    // Calculate level from Total XP
+    getLevelFromXp: (totalXp: bigint) => {
+        let level = 1;
+        let xp = Number(totalXp);
+
+        while (true) {
+            // XP needed to complete current level and reach next
+            const xpForNext = Math.floor(config.leveling.base * Math.pow(level, config.leveling.exponent));
+            if (xp < xpForNext) {
+                return level;
+            }
+            xp -= xpForNext;
+            level++;
+        }
+    },
+
+    // Get XP needed to complete the current level (for calculating next level threshold in isolation)
+    // Used internally or for display
+    getXpForNextLevel: (currentLevel: number) => {
+        return Math.floor(config.leveling.base * Math.pow(currentLevel, config.leveling.exponent));
+    },
+
+    // Cumulative XP addition
     addXp: async (id: string, amount: bigint, tx?: Transaction) => {
         return await withTransaction(async (txFn) => {
             // Get current state
@@ -20,30 +50,24 @@ export const levelingService = {
 
             if (!user) throw new Error("User not found");
 
-            let newXp = (user.xp ?? 0n) + amount;
-            let currentLevel = user.level ?? 1;
-            let levelUp = false;
+            const currentXp = user.xp ?? 0n;
+            const newXp = currentXp + amount;
 
-            // Check for level up loop
-            let xpForNextLevel = BigInt(levelingService.getXpForLevel(currentLevel));
-
-            while (newXp >= xpForNextLevel) {
-                newXp -= xpForNextLevel;
-                currentLevel++;
-                levelUp = true;
-                xpForNextLevel = BigInt(levelingService.getXpForLevel(currentLevel));
-            }
+            // Calculate new level based on TOTAL accumulated XP
+            const newLevel = levelingService.getLevelFromXp(newXp);
+            const currentLevel = user.level ?? 1;
+            const levelUp = newLevel > currentLevel;
 
             // Update user
             const [updatedUser] = await txFn.update(users)
                 .set({
                     xp: newXp,
-                    level: currentLevel,
+                    level: newLevel,
                 })
                 .where(eq(users.id, BigInt(id)))
                 .returning();
 
-            return { user: updatedUser, levelUp, currentLevel };
+            return { user: updatedUser, levelUp, currentLevel: newLevel };
         }, tx);
     },