/// <summary>
/// Generate an array of connection from the mapping input.
/// </summary>
/// <param name="mapping">A rotor wiring such as "HQZGPJTMOBLNCIFDYAWVEUSRKX"</param>
/// <returns>An array of connections</returns>
private Connection[] GenerateConnectionsFromMapping(string mapping, bool ignoreInvalidMapping = false)
{
bool valid = AlphabetUtils.IsValidMapping(mapping);
if (valid || ignoreInvalidMapping)
{
Connection[] result = new Connection[mapping.Length];
// Maps the regular alphabet order (ABCDEF...) to the input mapping.
for (int i = 0; i < mapping.Length; i++)
{
result[i] = new Connection(AlphabetUtils.Alphabet[i], mapping[i]);
}
return result;
}
else
{
throw new InvalidMappingException(string.Format("{0} is not a valid mapping", mapping));
}
}
/// <summary>
/// Generates an rotor of non random connections where the nth letter of the alphabet is mapped to the 26-nth letter.
/// Example : A -> Z, B -> Y, ..., Z -> A
/// </summary>
/// <param name="number">The number of connections. Generally 26 for the whole alphabet.</param>
/// <returns>An array of connections.</returns>
private Connection[] GenerateReverseAlphabeticalConnections(int number)
{
if (number < 1 || number > AlphabetUtils.Alphabet.Length)
{
throw new ArgumentOutOfRangeException();
}
Connection[] result = new Connection[number];
for (int i = 0; i < number; i++)
{
result[i] = new Connection(AlphabetUtils.Alphabet[i], AlphabetUtils.Alphabet[number - 1 - i]);
}
return result;
}
/// <summary>
/// Offsets the rotor of x steps clockwise. That is, the rotor key is translated to an offset.
/// In reality, makes the drum rotate of x notches, setting new paths for the current.
/// </summary>
public void OffsetRotor(int offset)
{
// Rebuilds the rotor
Connection[] incrementedRotor = new Connection[length];
for (int i = 0; i < length; i++)
{
incrementedRotor[i] = initialMapping[(i + offset) % length];
}
this.offset = offset;
mapping = incrementedRotor;
}