///<inheritdoc/>
public override string Run(string input, bool forward)
{
var keytable = new Alphabet(Alphabet.ToString())
{
Dimensions = Alphabet.Dimensions
};
var distinct = Key.Distinct().ToList();
for (int i = 0; i < distinct.Count; i++)
{
keytable.Move(distinct[i], i);
}
if (input.Length % 2 != 0)
{
input += Alphabet[Alphabet.Count - 1];
}
var multiplier = forward ? 1 : -1;
var output = new StringBuilder();
//Let the ciphering begin:
for (int i = 0; i < input.Length; i += 2)
{
var a = keytable.DimensionsOf(input[i]);
var b = keytable.DimensionsOf(input[i + 1]);
var newA = new Dimensions(b.X, a.Y);
var newB = new Dimensions(a.X, b.Y);
if (a.X == b.X || a.Y == b.Y)
{
newA = a;
newB = b;
//SamePoint
if (a == b)
{
newA.X = PrefferredOrientation == PrefferredOrientation.Horizontal ?
newA.X += multiplier : newA.X;
newA.Y = PrefferredOrientation == PrefferredOrientation.Vertical ?
newA.Y += multiplier : newA.Y;
newB = new Dimensions(newA.X, newA.Y);
}
//SameCol
else if (a.X == b.X)
{
newA.Y += multiplier;
newB.Y += multiplier;
}
//SameRow
else
{
newA.X += multiplier;
newB.X += multiplier;
}
newA.Limit(keytable.Dimensions);
newB.Limit(keytable.Dimensions);
}
output.Append(keytable[newA]);
output.Append(keytable[newB]);
}
return(output.ToString());
}
public void Save(Stream stream)
{
//header
using var writer = new BinaryWriter(stream);
//Header
writer.Write("EGMC");
//Alphabet
writer.Write("alph");
writer.Write(Alphabet.Count);
writer.Write(Alphabet.ToString());
//Whether we autoreset
writer.Write(AutoReset);
//Stator Indexing:
writer.Write("ETW ");
writer.Write("indx");
writer.Write(Stator.Indexing.Count);
writer.Write(Stator.Indexing.ToString());
//Stator Wiring
writer.Write("wire");
writer.Write(Stator.Wiring.Count);
writer.Write(Stator.Wiring.ToString());
//Reflector Indexing
writer.Write("UKW ");
writer.Write("indx");
writer.Write(Reflector.Indexing.Count);
writer.Write(Reflector.Indexing.ToString());
//Reflector Wiring
writer.Write("wire");
writer.Write(Reflector.Wiring.Count);
writer.Write(Reflector.Wiring.ToString());
//Rotors
writer.Write("ROTS");
writer.Write(Rotors.Count);
foreach (var rotor in Rotors)
{
//Indexing
writer.Write("indx");
writer.Write(rotor.Indexing.Count);
writer.Write(rotor.Indexing.ToString());
//Wiring
writer.Write("wire");
writer.Write(rotor.Wiring.Count);
writer.Write(rotor.Wiring.ToString());
//Turnover Notch
writer.Write("ntch");
writer.Write(rotor.TurnOver.Count);
foreach (var notch in rotor.TurnOver)
{
writer.Write(notch);
}
}
}
/// <summary>
/// Builds an <see cref="EnigmaMachine"/> with the provided parameters.
/// </summary>
/// <returns></returns>
public EnigmaMachine Build()
{
var shuffle = new Alphabet(_alphabet.ToString());
//the stator:
var stator = _stator;
if (stator == null)
{
stator = new EnigmaWheel(_alphabet.ToString(), _alphabet.ToString());
}
//the reflector
var reflector = _reflector;
if (reflector == null)
{
shuffle.Shuffle();
reflector = new EnigmaWheel(_alphabet.ToString(), shuffle.ToString());
reflector.Reflect();
}
//the rotors
List <Rotor> rotors;
if (_rotors == null)
{
rotors = new List <Rotor>();
for (int i = 0; i < _rotorCount; i++)
{
string notches = "";
for (int n = 0; n < _notchCount; n++)
{
char c;
do
{
int rnd = Horus.Random(0, _alphabet.Count);
c = _alphabet[rnd];
} while (notches.Contains(c));
notches += c;
}
shuffle.Shuffle();
var rotor = new Rotor(_alphabet.ToString(), shuffle.ToString(), notches);
rotors.Add(rotor);
}
}
else
{
rotors = new List <Rotor>(_rotors);
}
//the actual construction
return(new EnigmaMachine(rotors)
{
Alphabet = _alphabet,
AutoReset = _autoReset,
Stator = stator,
Reflector = reflector,
});
}