/////////////////////////
//
// This program reads in a list of hash values and stores them in a
// vector. It then reads in a second list of hashes and compares each
// to the first list. If any match, a message is output that says so.
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
#include <vector>
using namespace std;

void print_hash_vector(vector <string>);
vector <string> load_hashes();
void print_case_vectors(vector<string> , vector<string> );
void load_case_file( vector<string> &, vector<string> &);
void print_instructions();
int compare_hashes_with_case (vector <string>, vector <string>, vector <string>);

int main (){

  vector<string> case_names, case_hashes, known_hashes;
  int matches = 0;
  char input;
  bool done = 0;


  // Loop until someone hits q and done is set true
  while (!done){
    print_instructions();
    cin >> input;
    switch (input){
    case 'H':
    case 'h':
      known_hashes = load_hashes();
      break;
    case'C':
    case 'c':
      load_case_file(case_names, case_hashes);
      break;
    case 'M':
    case 'm':
      matches = compare_hashes_with_case (case_names, case_hashes, known_hashes );
      cout << "Number of matches: " << matches << endl;
      break;
    case'D':
    case 'd':
      cout << "Hash Set: " << endl;
      print_hash_vector(known_hashes);
      cout << endl << endl << endl << endl;
      cout <<"Case file: " << endl;
      print_case_vectors(case_names, case_hashes);
      cout << endl;
      break;
    case 'Q':
    case 'q':
      done = 1;
      break;
    default:
      cout << "Invalid command character" << endl;      
    }
  }

  return 0;
}


//////////////////////////////////////
// This function takes an ifstream and
// loads value from it into a vector of strings
vector <string> load_hashes() {
  
  vector<string> thevector;
  string current_value, headers;
  string hashfilename;
  ifstream inputfile;
  
  // Get the filename to be used
  cout << "Please enter the name of the hash file: ";
  cin >> hashfilename;

  // Try and open that file. Die if it fails.
  inputfile.open(hashfilename.c_str()); 
  if (!inputfile){
    cerr << "File: " << hashfilename << " not found. Aborting." << endl;
    exit(1);
  }

  // now get rid of the 3 headerlines
  for (int i=0; i < 3; i++)
    getline(inputfile, headers);

  // Read the remaining values and enter them into the vector
  while (inputfile >> current_value){
    thevector.push_back(current_value);
  }

  return thevector;
}


/////////////////////////////////////
// this fuction prints a vector of strings,
// one entry to a line
void print_hash_vector(vector <string> hashes) {

  for (int i = 0; i < hashes.size(); i++){
    cout << hashes[i] << endl;
  }
}

/////////////////////////////////////
// Take a couple of vectors as reference parameters,
// ask for a file name, read it, and load the contents
// of the file into the two vectors
void load_case_file(vector<string> & names,vector<string> & hashes){

  string casefilename;
  ifstream inputfile;
  string headers, current_file_string, current_hash_string;

  // Get the filename to be used
  cout << "Please enter the name of the file : ";
  cin >> casefilename;

  // Try and open that file. Die if it fails.
  inputfile.open(casefilename.c_str()); 
  if (!inputfile){
    cerr << "File: " << casefilename << " not found. Aborting." << endl;
    exit(1);
  }

  // now get rid of the 3 headerlines
  for (int i=0; i < 3; i++)
    getline(inputfile, headers);

  // Read the remaining values and enter them into the vector
  while (inputfile >> current_file_string >> current_hash_string){
    names.push_back(current_file_string);
    hashes.push_back(current_hash_string);
  }
}

/////////////////////////////////////
// Print the vectors associated with the case
// 
void print_case_vectors(vector<string> files, vector<string> hashes){

  for (int i = 0; i < files.size(); i++){
    cout << files[i] << "  " << hashes[i] << endl;
  }
}

/////////////////////////////////////
// Loop over the vector of case hashes. For each hash,
// loop over the known hashes. If they match, print the file
// name and matching hash.
int compare_hashes_with_case (vector <string> file_names, vector <string>file_hashes, 
			      vector <string> known_hashes){

  int matches = 0;
  for (int i = 0; i < file_names.size();i++){
    for (int j = 0; j < known_hashes.size();j++){
      if (file_hashes[i] == known_hashes[j]){
	cout << "File: " << file_names[i] << " matches known hashes with hash: "
	     << known_hashes[j] << endl;
	matches++;
      }
    }
  }

  return matches;
}

void print_instructions(){
  

  cout << "This program reads a file containing a set of hashes, " << endl;
  cout << "then reads a second file consisting of filenames and hashes. " << endl;
  cout << "It will then identify each file from the second file that match " << endl;
  cout << "a hash from the first file." << endl << endl;

  cout << "Menu choices:" << endl;
  cout << left;
  cout << setw(5) << "H" << setw(45)  << "Load the hash set" << endl;
  cout << setw(5) << "C" << setw(45) << "Load the case file" << endl;
  cout << setw(5) << "M" << setw(45) << "Compare the hash set and case file" << endl;
  cout << setw(5) << "D" << setw(45) << "Print hash set and case file" << endl;
  cout << setw(5) << "" << setw(45) << "(for debugging)" << endl;
  cout << setw(5) << "Q" << setw(45) << "Quit the program" << endl;
  cout << endl << endl << "Your choice: ";
    }