/************************************************************
 *
 *                   phone.c
 *
 *  The routines in this file maintain the phone book data
 *  structure.  All access to this data structure must be
 *  through the routines in this file.
 *
 **********************************************************/

#include <stdio.h>
#include <string.h>
#include "phone.h"

/*
 *  SIZE is the length of the array used to store the
 *  phone list
 */

#define SIZE    200

/*
 *  phone_table is the array that stores the phone list.
 *  Numbers is the number of entries in the phone list.
 */

static struct phone_struct phone_table[SIZE];

static int Numbers = 0;


/*
 *  read_phone_list
 *
 *  Purpose: transfer the phone list from disk to internal storage
 *
 *  Pre-conditions: the phone list is initially empty
 *
 *  Post-conditions: the phone_table array has the contents of the
 *                   disk file
 */

void read_phone_file (FILE* fid)
{
    int n;
    int i;

    i = 0;

    while (TRUE) {

        n = fscanf(fid,"%20s %10s",
			                 &(phone_table[i].name[0]), 
			                 &(phone_table[i].phone)[0]);

        if (n < 0)
            break;

        i++;
    }

    Numbers = i;
}

/*
 *  get_phone_number
 *
 *  Purpose:  look up the name corresponding to a phone number
 *
 *  Pre-conditions: the name is in the phone list
 *
 *  Post-conditions: returns the number corresponding to the
 *                   name that was passed as a parameter
 */

char* get_phone_number (char* name)
{
    int i;

    for (i = 0; i < Numbers; i++) {
        if ( strcmp (name, phone_table[i].name) == 0 ) {
            return (phone_table[i].phone);
        }
    }

    return (NULL);
}

/*------------------end of phone.c----------------*/