Added Operations and Combat Conditions (#22)

* Added Operations and Combat Conditions

+ Added Multiply, Division and Subtract operations for modifiers
+ Added Combat Conditions Effects form Ars Armorum

* Added Math.floor()

source/module/M5Base.ts

@@ -95,6 +95,9 @@ export enum M5ModOperation {
 	ADD = "add",
 	SET = "set",
 	FIXED = "fixed",
+	MULTIPLY = "multiply",
+	SUBTRACT = "subtract",
+	DIVISION = "division",
 }
 
 export interface M5ItemMod {

source/module/actors/M5ModAggregate.ts

@@ -126,6 +126,27 @@ export default class M5ModAggregate {
 				const bonus = mods.map((p) => p.mod.value).reduce((a, b) => a + b, 0);
 				ret.value = Math.max(0, ret.value + bonus);
 			}
+
+			mods = arr.filter((pair) => pair.mod.operation === M5ModOperation.SUBTRACT);
+			if (mods.length !== 0) {
+				ret.mods = ret.mods.concat(mods.map(this.pairAsSource));
+				const bonus = mods.map((p) => p.mod.value).reduce((a, b) => a - b, 0);
+				ret.value = Math.max(0, ret.value + bonus);
+			}
+
+			mods = arr.filter((pair) => pair.mod.operation === M5ModOperation.MULTIPLY);
+			if (mods.length !== 0) {
+				ret.mods = ret.mods.concat(mods.map(this.pairAsSource));
+				const bonus = mods.map((p) => p.mod.value).reduce((a, b) => a * b, 0);
+				ret.value = Math.max(0, ret.value + bonus);
+			}
+
+			mods = arr.filter((pair) => pair.mod.operation === M5ModOperation.DIVISION);
+			if (mods.length !== 0) {
+				ret.mods = ret.mods.concat(mods.map(this.pairAsSource));
+				const bonus = mods.map((p) => p.mod.value).reduce((a, b) => Math.floor(a / b), 0);
+				ret.value = Math.max(0, ret.value + bonus);
+			}
 		}
 
 		return ret;