///////////////////////////////////////////////////////////////
//    Proj2.C                                                //
//    CMSC 341 - Fall 2001 Project 2                         //
//    Kyu Bae xxx-xx-5868, Section 201                       //
//    kyu_bae@yahoo.com / kbae1@umbc.edu                     //
//    Created :  20 September 201                            //
//    Current :  1  October   2001                           //
///////////////////////////////////////////////////////////////


#include "dsexceptions.h"
#include <string.h>
#include <stdlib.h>
#include <iostream.h>
#include <fstream>
#include "Data.H"
#include "LinkedList.H"

//////////////////////////////////////////////////////////////
// Object: 
// This project will read data from  a fie and build the
// doubly circular linked 
// list. Ths data in the file consists ofcharacters/integer 
// pairs except the first entry which is a single integer. 
// This program will read the data from the file and store
// each character/
// integer in the linked list in the order it was found in 
// the file. Characters represent a scamble message. This 
// program will print the message by moving from node to node 
// in the list based on the integer found in the node. The 
// integer might be positive and negative.
/////////////////////////////////////////////////////////////
//    Main():
//    Read data from the file and inser into the list and 
//    Print the message out by moving around the list ..
//
////////////////////////////////////////////////////////////
int main(int argc, char *argv[])
{
    // checking for the command line arguments
    if(argc != 2) {
        cerr << "Invalid number of command line argument\n"
             << "Usage is Proj2 <filename>\n"
             << "Aborting" << endl;
        exit(1);
    }
    //check for file open
    ifstream Infile(argv[1], ios::in);
    if (! Infile) {
        cerr << "cannot open " << argv[2] << " for input" << endl;
        cerr << "Program terminating" << endl;
        exit(1);
    }

    int nStart;
    char cData;
    char *token;
    char buffer[256];

    List<Data> newList;
    ListItr<Data> itrZeroth = newList.zeroth();
    Infile >> nStart;
    //checking for the blank lines
    if (nStart == 0) {
       cout << "List is Empty and  Now Exiting Program!!" 
	    << endl << endl;
       exit(1);
    }

    while (Infile.getline(buffer, 255, '\n')) {
       if (strlen(buffer) == 0) // checking for the blank
            continue;

        cData = buffer[0];
        token = strtok(&(buffer[1])," \t" );
        newList.insert(Data(cData, atoi(token)), itrZeroth);
        //creating the Data object and inserting
    }
    Infile.close();

    int i;
    Data tmpData;
    //descrambling the message
    while( nStart != 0 ) {
        if(nStart > 0)
            for (i = 0; i < nStart; i++)
	       itrZeroth.advance();//moving forward
        else {
            nStart *= -1;
            for (i = 0; i < nStart; i++)
	       itrZeroth.retreat();//moving backward
        }
        try { // throwing exceptions here
            tmpData = itrZeroth.retrieve();
        } catch (BadIterator ex) {
             cout << "ERROR : " << endl;  
             cout << "TRYING TO GET something there isn't there" << endl;
             }
        cout << tmpData;
        nStart = tmpData.getKey();
    }
    cout << endl;
    return 0;
}
///////////////////////////////////////////////////////////
//        THE END OF PROGRAM!!!!!!                       //
///////////////////////////////////////////////////////////