Upgrade item sheets

module/models/skill.mjs

@@ -21,4 +21,47 @@ export default class LethalFantasySkill extends foundry.abstract.TypeDataModel {
   get skillCategory() {
     return game.i18n.localize(CATEGORY[this.category].label)
   }
+  
+  prepareDerivedData() {
+    super.prepareDerivedData();
+    this.skillTotal = this.computeBase();
+  }
+
+  computeBase() {
+    let actor = this.parent?.actor;
+    if (!actor) {
+      return `${this.base  } + ${  String(this.bonus)}`;
+    }
+
+    // Split the base value per stat : WIS,DEX,STR,INT,CHA (example)
+    const base = this.base;
+    let baseSplit = base.split(",");
+    let baseSplitLength = baseSplit.length;
+    if ( baseSplitLength > 0) {
+      // Select the max stat value from the parent actor
+      let maxStat = 0;
+      for (let i = 0; i < baseSplitLength; i++) {
+        const stat = baseSplit[i];
+        const statValue = actor.system.characteristics[stat.toLowerCase()]?.value || 0;
+        if (statValue > maxStat) {
+          maxStat = statValue;
+        }
+      }
+      return maxStat;
+    } else {
+      // Split with +  calculate the total
+      baseSplit = base.split("+");
+      baseSplitLength = baseSplit.length;
+      if ( baseSplitLength > 0) {
+        let total = 0;
+        for (let i = 0; i < baseSplitLength; i++) {
+          const stat = baseSplit[i];
+          const statValue = actor.system.characteristics[stat.toLowerCase()]?.value || 0;
+          total += statValue;
+        }
+        return total
+     }
+    }
+    return `${this.base  } + ${  String(this.bonus)}`;
+  }
 }