From 9a7353e973344c64868a3755f7c69d55d8103518 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Sun, 19 Jul 2015 00:00:59 -0700
Subject: [PATCH] Expand Reflector to valid reflection series

---
 Enigma/Components.swift       | 31 ++++++++++++++++++++++++++++++-
 EnigmaTests/EnigmaTests.swift | 20 ++++++++++++++++++++
 2 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/Enigma/Components.swift b/Enigma/Components.swift
index 436fbed..0e4425c 100644
--- a/Enigma/Components.swift
+++ b/Enigma/Components.swift
@@ -80,7 +80,36 @@ class Rotor: FixedRotor {
 }
 
 
-class Reflector: FixedRotor { }
+class Reflector: FixedRotor {
+    enum Wiring: String {
+        case EnigmaA = "EJMZALYXVBWFCRQUONTSPIKHGD"
+        case EnigmaB = "YRUHQSLDPXNGOKMIEBFZCWVJAT"
+        case EnigmaC = "FVPJIAOYEDRZXWGCTKUQSBNMHL"
+        case EnigmaM4R1BThin = "ENKQAUYWJICOPBLMDXZVFTHRGS"
+        case EnigmaM4R1CThin = "RDOBJNTKVEHMLFCWZAXGYIPSUQ"
+    }
+
+    enum Error: ErrorType {
+        case InvalidReflection
+    }
+
+    override init(series: [Character]) throws {
+        try super.init(series: series)
+        try validateReflector(series)
+    }
+
+    func validateReflector(series: [Character]) throws {
+        for (offset, c) in series.enumerate() {
+            if let alphabetOffset = Reflector.alphabet.indexOf(c) {
+                if series[alphabetOffset] != Reflector.alphabet[offset] {
+                    throw Error.InvalidReflection
+                }
+            } else {
+                throw EncoderError.InvalidCharacter(ch: c)
+            }
+        }
+    }
+}
 
 
 /** A Plugboard is a Cryptor that substitutes one character for another based on a set of pairs. A pair of characters is mutually exclusive of other pairs; that is, a character can only belong to one pair. Furthermore, the Plugboard always trades one character for the same character and vice versa. */
diff --git a/EnigmaTests/EnigmaTests.swift b/EnigmaTests/EnigmaTests.swift
index 359d0d0..afe536c 100644
--- a/EnigmaTests/EnigmaTests.swift
+++ b/EnigmaTests/EnigmaTests.swift
@@ -41,6 +41,26 @@ class RotorTests: XCTestCase {
 }
 
 
+class ReflectorTests: XCTestCase {
+    func testThatReflectorReflects() {
+        var reflector: Reflector! = nil
+        do {
+            reflector = try Reflector(series: Reflector.Wiring.EnigmaA.rawValue)
+        } catch let error {
+            XCTFail("Error creating reflector: \(error)")
+        }
+        do {
+            let encodeA = try reflector.encode("A")
+            let encodeE = try reflector.encode("E")
+            XCTAssertEqual(encodeA, "E")
+            XCTAssertEqual(encodeE, "A")
+        } catch {
+            XCTFail("Reflector encoding failed")
+        }
+    }
+}
+
+
 class PlugboardTests: XCTestCase {
     func testThatEmptyPlugboardPassesThroughAllCharacters() {
         let plugboard = Plugboard()