// cyk_main.cpp   read in grammar
//                call chomsky to convert grammar
//                read string
//                call cyk to determine if accepted
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>
#include <cstring>
#include "cyk.h"

using namespace std;

int main(int argc, char * argv[])
{
  FILE * input_grammar; // file handle
  char line[100];       // input line from file
  int n;                // input line length
  int i, j, k;          // temporary variables

  char P[100][100];     // raw productions
  int np = 0;           // number of productions

  char new_var = 'Z';   // count down for new variable

  // data for CYK
  char x[100];
  Prod1 P1[100];
  int np1 = 0;
  Prod2 P2[100];
  int np2 = 0;


  if (argc < 2)         // check command line
  {
    cout << "Provide the file name of a grammar" << endl;
    exit(1);
  }
  input_grammar = fopen(argv[1], "r");
  if (input_grammar == NULL) // check if file opened
  {
    cout << "could not open " << argv[1] << endl;
    exit(1);
  }

  // clear P array
  for (i=0; i<100; i++)
    for (j=0; j<100; j++)
      P[i][j] = 0;

  while(1) // read file
  {
    i=0;
    j=0;
    fgets(line, 99, input_grammar);
    if (feof(input_grammar)) break;      // exit while loop on eof

    cout << line;                        // no endl, has new line in it
    if (line[0] == '#') continue;        // skip comments
    // find first variable
    n = strlen(line);
    n--;                       // ignore new line character
    while(line[i] == ' ') i++; // skip spaces
    if (i>=n) continue;
    P[np][j] = line[i];
    i++;
    j++;

    // find ->
    while ((line[i] != '>') && (i<=n)) i++; // find '>'
    i++;
    if (i>=n) continue;
    while ((line[i] == ' ')&&(i<=n)) i++; // skip spaces

    // find rest of variables
    while (i<n)
    {
      P[np][j] = line[i];
      i++;
      j++;
    }
    P[np][j] = 0; // stop signal
    if(j>1) np++;
  }

  cout << "Productions in P matrix" << endl;
  for (i=0; i<np; i++)
  {
    cout << i << ". ";
    for (j=0; (j<99)&&(P[i][j]!=0); j++)
    {
       cout << P[i][j] << ' ';
    }
    cout << endl;
  }

  // Do Chomsky Normal Form  P1 and P2 arrays, np1 and np2 sizes

  for (i=0; i<np; i++)
  {
    if (P[i][2] != 0)  // convert terminals to variables, making rules
    {
      for (j=1; (j<100)&&P[i][j]!=0; j++)
      {
        if (islower(P[i][j]))
	{
          P[np][0] = new_var;
          P[np][1] = P[i][j];
          P[i][j]  = new_var;
          np++;
          new_var--;
          if (new_var=='S') new_var--;
	}
      }
    }
  }


  cout << "Productions in P matrix after first pass Chomsky" << endl;
  for (i=0; i<np; i++)
  {
    cout << i << ". ";
    for (j=0; (j<99)&&(P[i][j]!=0); j++)
    {
       cout << P[i][j] << ' ';
    }
    cout << endl;
  }


  for (i=0; i<np; i++)
  {
    if (P[i][3] != 0)  // convert last two variables to variable, making rules
    {
      for (j=99; j>1; j--)
      {
        if ((P[i][j]!=0)&&(P[i][j+1]!=0))
	{
          P[np][0] = new_var;
          P[np][1] = P[i][j];
          P[np][2] = P[i][j+1];
          np++;
          P[i][j+1] = 0;
          P[i][j] = new_var;
          new_var--;
          if (new_var=='S') new_var--;
	}
      }
    }
  }

  cout << "Productions in P matrix after Chomsky" << endl;
  for (i=0; i<np; i++)
  {
    cout << i << ". ";
    for (j=0; (j<99)&&(P[i][j]!=0); j++)
    {
       cout << P[i][j] << ' ';
    }
    cout << endl;
  }


  cout << "set up P1 and P2 for CYK" << endl;
  // set up P1 and P2
  for (i=0; i<np; i++)
  {
    if (P[i][2] == 0)
    {
      np1++;
      P1[np1].A = P[i][0];
      P1[np1].alpha = P[i][1];
    }
    else if (P[i][3] == 0)
    {
      np2++;
      P2[np2].A = P[i][0];
      P2[np2].B = P[i][1];
      P2[np2].C = P[i][2];
    }
    else
    {
      cout << "not in Chomsky normal form " << i << endl;
    }
  }



  // read a string from keyboard
  while(1)
  {
    cout << "Type in an input string" << endl;
    cin >> x ;
    cout << "string read |" << x << "|" << endl;
    n = strlen(x);
    if (n<2) break;              // input finished

    cyk(x, n, P1, np1, P2, np2);
  }

  cout << "finished cyk_main" << endl; 
  return 0;
}