bgneal@0: // Copyright (C) 2012 by Brian Neal.
bgneal@0: // This file is part of Cpp-Enigma, the Enigma Machine simulation.
bgneal@0: // Cpp-Enigma is released under the MIT License (see License.txt).
bgneal@0: //
bgneal@0: // rotor.cpp - Implementation file for the rotor class.
bgneal@0: 
bgneal@0: #include <set>
bgneal@0: #include <array>
bgneal@0: #include <algorithm>
bgneal@0: #include "rotor.h"
bgneal@0: 
bgneal@0: using namespace enigma;
bgneal@0: 
bgneal@0: namespace
bgneal@0: {
bgneal@0:    const char* const ucase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
bgneal@0:    const std::set<char> ucase_set(ucase, ucase + 26);
bgneal@0: }
bgneal@0: 
bgneal@0: rotor::rotor(const char* name, const char* wiring, int ring_setting, const char* stepping)
bgneal@0:  : rotor_name(name),
bgneal@0:    wiring_str(wiring),
bgneal@0:    ring_setting(ring_setting),
bgneal@0:    pos(0),
bgneal@0:    rotations(0)
bgneal@0: {
bgneal@0:    // check wiring length
bgneal@0:    if (wiring_str.size() != 26)
bgneal@0:    {
bgneal@0:       throw rotor_error("invalid wiring length");
bgneal@0:    }
bgneal@0: 
bgneal@0:    // ensure wiring contains only uppercase letters & every char must appear
bgneal@0:    // exactly once:
bgneal@0: 
bgneal@0:    std::array<int, 26> letter_counts {{ 0 }};
bgneal@0:    for (int i = 0; i < 26; ++i)
bgneal@0:    {
bgneal@0:       const char c(wiring_str[i]);
bgneal@0: 
bgneal@0:       if (ucase_set.find(c) == ucase_set.end())
bgneal@0:       {
bgneal@0:          throw rotor_error("invalid wiring");
bgneal@0:       }
bgneal@0:       ++letter_counts[c - 'A'];
bgneal@0:    }
bgneal@0: 
bgneal@0:    if (std::find_if(letter_counts.begin(),
bgneal@0:                     letter_counts.end(),
bgneal@0:                     [](int n) { return n != 1; }) != letter_counts.end())
bgneal@0:    {
bgneal@0:       throw rotor_error("invalid wiring; duplicate letter");
bgneal@0:    }
bgneal@0: }