mpags-cipher.cpp

// Standard Library includes
#include <iostream>
#include <fstream>
#include <string>

// Our project headers
#include "CaesarCipher.hpp"
#include "ProcessCommandLine.hpp"
#include "TransformChar.hpp"

//! Main function of the mpags-cipher program
int main(int argc, char* argv[]) {
  // Command line inputs
  bool helpRequested {false};
  bool versionRequested {false};
  std::string inputFile {""};
  std::string outputFile {""};
  std::string cipherKey {""};
  bool cipherDecrypt {false};

  bool commandLineParsed {processCommandLine(argc, argv, helpRequested, versionRequested, inputFile, outputFile, cipherKey, cipherDecrypt)};

  if(!commandLineParsed) {
    return 1;
  }

  // Handle help, if requested
  if (helpRequested) {
    doPrintCommandLineHelp();
    // Help requires no further action, so return from main
    // with 0 used to indicate success
    return 0;
  }

  // Handle version, if requested. Like help, requires no further action,
  // so return from main with zero to indicate success
  if (versionRequested) {
    doPrintCommandLineVersion();
    return 0;
  }

  // Read in user input from stdin/file
  char inputChar {'x'};
  std::string inputText {""};

  if(inputFile.empty()) {
    // Loop over stdin until Return then CTRL-D pressed (EOF)
    while (std::cin >> inputChar) {
      inputText += transformChar(inputChar);
    }
  }
  else {
    // Create ifstream and loop over that until EOF
    std::ifstream inFileStream {inputFile};
    if (inFileStream.good()) {
      while (inFileStream >> inputChar) {
        inputText += transformChar(inputChar);
      }
    }
    else {
      std::cerr << "[error] bad input stream, cannot open/read file '"
                << inputFile
                <<"'\n";
    }
  }

  // TEXT ENCRYPTION/DECRYPTION
  std::string outputText {""};
  bool cryptOK {CaesarCipher(inputText, cipherKey, cipherDecrypt, outputText)};
  if (!cryptOK) {
    std::cerr << "[error] text processing with Caesar Cipher failed\n";
  }

  // Output the input text to stdout or file if filename supplied
  if (outputFile.empty()) {
    std::cout << outputText << "\n";
  }
  else {
    std::ofstream outFileStream {outputFile};
    if (outFileStream.good()) {
      outFileStream << outputText << "\n";
    }
    else {
      std::cerr << "[error] bad output stream, cannot open/write file '"
                << outputFile
                <<"'\n";
    }
  }

  // No requirement to return from main, but we do so for clarity and
  // consistency with other functions.
  return 0;
}