/***********************************************************************
* prog2.cpp
*
* A simple program to implement user commands for manipulating
* an expandable queue.
*
* Written by Paul Bonamy - 23 May 2010
* Rewritten in pure C - 20 July 2010
************************************************************************/

#include <stdio.h>          // replaces iostream for I/O
#include <stdlib.h>         // malloc lives here
#include <ctype.h>          // we get isspace() from here
#include "equeue.h"

/***********************************************************************
 * int main()
 *
 * main function for the program. deals with accepting/parsing
 * user input and generally keeping things running
 *
 * no parameters / always returns 0
 ***********************************************************************/
int main () {
    EQUEUE *queue;  // our queue
    char cmd;       // this will hold our user command
    int  value;     // user-supplied value to insert / remove
    
    queue = (EQUEUE *)malloc(sizeof(EQUEUE));
    equeue_init(queue);         // initialize the queue structure
    
    scanf("%c", &cmd);          // read in an intial command
    
    /*
     * scanf will return whatever character it finds, so we need some way
     * to weed out the whitespaces while looking for characters
     */
    while(isspace(cmd)) { scanf("%c", &cmd); }
    
    while(cmd != 'q') {         // dump out if we get a q
        switch (cmd) {          // figure out what we're doing
            case 'i':           // insert into queue
                scanf("%d", &value);   // get the value to insert
                equeue_enqueue(queue, value);    // do the insert
                break;
            
            case 'e':           // empty the queue
                equeue_empty(queue);
                break;
            
            case 'r':           // dequeue and print last value
                if(equeue_dequeue(queue, &value))
                    { printf("%d\n", value); }
                else
                    { printf("empty\n"); }
                break;
            
            default:            // here for giggles
                printf("Oi! That's not a legal command\n");
        }
        
        scanf("%c", &cmd);      // get the next command
        while(isspace(cmd)) { scanf("%c", &cmd); }    
    }
    
    equeue_cleanup(queue);
    free(queue);
    
    return 0;
}