Math Expression Class to generate math problems

ProjectClock/MathExpressions.swift

@@ -0,0 +1,86 @@
+//
+//  MathExpressions.swift
+//  ProjectClock
+//
+// Class that will generate a simple math expression
+
+import Foundation
+
+enum MathElement : CustomStringConvertible {
+    case Integer(value: Int)
+    case Percentage(value: Int)
+    case Expression(expression: MathExpression)
+
+    var description: String {
+        switch self {
+        case .Integer(let value): return "\(value)"
+        case .Percentage(let percentage): return "\(percentage)%"
+        case .Expression(let expr): return expr.description
+        }
+    }
+
+    var nsExpressionFormatString : String {
+        switch self {
+        case .Integer(let value): return "\(value).0"
+        case .Percentage(let percentage): return "\(Double(percentage) / 100)"
+        case .Expression(let expr): return "(\(expr.description))"
+        }
+    }
+}
+
+enum MathOperator : String {
+    case plus = "+"
+    case minus = "-"
+    case multiply = "*"
+    case divide = "/"
+
+    static func random() -> MathOperator {
+        let allMathOperators: [MathOperator] = [.plus, .minus, .multiply, .divide]
+        let index = Int(arc4random_uniform(UInt32(allMathOperators.count)))
+
+        return allMathOperators[index]
+    }
+}
+
+class MathExpression : CustomStringConvertible {
+    var lhs: MathElement
+    var rhs: MathElement
+    var `operator`: MathOperator
+
+    init(lhs: MathElement, rhs: MathElement, operator: MathOperator) {
+        self.lhs = lhs
+        self.rhs = rhs
+        self.operator = `operator`
+    }
+
+    var description: String {
+        var leftString = ""
+        var rightString = ""
+
+        if case .Expression(_) = lhs {
+            leftString = "(\(lhs))"
+        } else {
+            leftString = lhs.description
+        }
+        if case .Expression(_) = rhs {
+            rightString = "(\(rhs))"
+        } else {
+            rightString = rhs.description
+        }
+
+        return "\(leftString) \(self.operator.rawValue) \(rightString)"
+    }
+
+    var result : Any? {
+        let format = "\(lhs.nsExpressionFormatString) \(`operator`.rawValue) \(rhs.nsExpressionFormatString)"
+        let expr = NSExpression(format: format)
+        return expr.expressionValue(with: nil, context: nil)
+    }
+
+    static func random() -> MathExpression {
+        let lhs = MathElement.Integer(value: Int(arc4random_uniform(10)))
+        let rhs = MathElement.Integer(value: Int(arc4random_uniform(10)))
+
+        return MathExpression(lhs: lhs, rhs: rhs, operator: .random())
+    }
+}

ProjectClock/NotificationLogic.swift

@@ -34,3 +34,4 @@ func puzzleAction() {
 func smashAction() {
     
 }
+