/* listtester.c 
 * Chris Kern
 *
 * The way-too-elaborate interactive test program for linked lists.  Hit 'h' for help. */

#include <strings.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include "linklist.h"
#define MAX_BUFFER 200

/* The global list. */
struct list *list;

/* The current number of nodes. */
int number;

/* A buffer, and the pointer to the buffer. */
char buf[MAX_BUFFER];
char *buffer = buf;

/* A helper function to print the current element of the list, and the number of nodes. */
void printinfo() {

  printf("Current number of nodes: %i\n", number);
  if (!list->cursor->item) printf("The current node does not have any contents.\n");
  else printf("The value of the current node is \"%s\"\n", list->cursor->item);

} /* printinfo() */

/* A helper function to clear the buffer. */
void clearbuf() {

  /* Set all the buffer elements to 0. */
  /* WARNING: bzero is not an ANSI function. */
  bzero(buf, MAX_BUFFER);

} /* clearbuf() */


/* Main function */
int main() {

  /* Variable declarations. */
  int command;
  int test;
  struct node *temp;

  /* Print introductory material */
  printf("-----------------------\n");
  printf("Linked List program\n");
  printf("v1.0 Chris Kern\n");
  printf("Type 'h' for help.\n");
  printf("-----------------------\n\n");

  /* Create the new list. */
  list = CreateList("");
  number = 1;

  /* Print the current item. */
  printinfo();
  
  /* This main loop will continue until "q" is pressed. */
  while (1) {

    printf("\nCommand: ");

    /* Read characters until the newlines are cleared. */
    while ((command = getchar()) == '\n');
    
    /* Parse input. */
    switch(command) {


    case 'b':
      /* Add a node to the front (beginning) */
      
      /* Accept input for the contents of the node. */
      clearbuf();
      printf("\nType the contents for the node, which will be added at the front.\n");
      scanf("%s", &buf);
      
      /* Attempt to add the item. */
      test = AddToFront(buf, list);
      
      /* If it fails, print a message.  In either case, go back and get another character. */
      if (!test) {

        printf("Add failed: Memory allocation fault.\n");

      } /* if */
     
      /* Increment counter. */
      if (test) number++;
      break;
 
    case 'c':
      /* Set current value */
      
      printinfo();
      /* Accept input for the new contents. */
      clearbuf();
      printf("\nType the new contents for this node.\n");
      scanf("%s", &buf);

      /* Attempt to change the value. */
      test = SetValue(buf, list);

      /* If it fails, print a message. */
      if (!test) {

        printf("Set failed: Memory allocation fault.\n");

      } /* if */
      break;

    case 'd':
      /* Delete current element */
      
      /* You cannot delete the only element of a list. */
      if (number == 1) {

        printf("\nYou cannot delete the only element in a list.\n");
        break;

      }
      
      else {
        DeleteCurrentElement(list);
        number--;
        printinfo();
      }
      break;

    case 'e':
      /* Add a node to the end. */
      
      /* Accept input for the contents of the node. */
      clearbuf();
      printf("\nType the contents for the node, which will be added at the end.\n");
      scanf("%s",&buf);

      /* Attempt to add the item. */
      test = AddToEnd(buf, list);
      
      /* If it fails, print a message.  In either case, go back and get another character. */
      if (!test) {

        printf("Add failed: Memory allocation fault.\n");

      } /* if */

      /* If the add succeeds, increment the counter. */
      if (test) number++;
      break;

    case 'f':
      /* Find an element, move the cursor. */

      /* Accept input. */
      clearbuf();
      printf("\nType the string you wish to search for.\n");
      scanf("%s",&buf);

      /* Try to find the element. */
      test = FindElement(buf, list);

      /* If the find failed, print a message. */
      if (!test) {

        printf("Find failed: Element not in list.\n");

      } /* if */
      break;

    case 'g':
      /* Get current value. */
      if (!list->cursor->item) printf("\nThe current node does not have any contents.\n");
      else printf("The value of the current node is \"%s\"\n", list->cursor->item); 
      break;

    case 'h':
      /* Help. */
      printf("\nThis program supports the following commands:\n");
      printf("(b) Add an item to the beginning of the list.\n");
      printf("(c) Change the value of the current item.\n");
      printf("(d) Delete the current element of the list.\n");
      printf("(e) Add an item to the end of the list.\n");
      printf("(f) Search for an element and move the cursor there.\n");
      printf("(g) Print the value at the current item.\n");
      printf("(h) Help.\n");
      printf("(i) Print the current item value and the number of nodes in the list.\n");
      printf("(j) Advance the cursor forward.\n");
      printf("(k) Move the cursor backwards.\n");
      printf("(l) Load a list from a file.\n");
      printf("(p) Print the whole list to the screen.\n");
      printf("(q) Quit.\n");
      printf("(r) Reset the cursor to the first element of the list.\n");
      printf("(s) Sort the list in alphabetical order.\n");
      printf("(w) Write the list to a file.\n\n");
      break;

    case 'i':
      /* Info */
      printinfo();
      break;

    case 'k':
      /* Advance the cursor. */

      /* Attempt to advance the cursor. */
      test = Advance(list);

      /* If it fails, print an error message.  Otherwise, print the new value. */
      if (!test) {

        printf("\nYou are at the end of the list!\n");

      } /* if */

      if (test) {

        if (!list->cursor->item) printf("\nThe current node does not have any contents.\n");
        else printf("\nThe value of the current node is \"%s\"\n", list->cursor->item); 

      } /* if */
      break;

    case 'j':
      /* Move the cursor back. */

      /* Attempt to move the cursor back. */
      test = GoBack(list);

      /* If it fails, print an error message.  Otherwise, print the new value. */
      if (!test) {

        printf("\nYou are at the beginning of the list!\n");

      } /* if */

      if (test) {

        if (!list->cursor->item) printf("\nThe current node does not have any contents.\n");
        else printf("\nThe value of the current node is \"%s\"\n", list->cursor->item); 

      } /* if */
      break;
      
    case 'l':
      

      /* Load from a file. */
      clearbuf();
      printf("\nEnter the file to load.\n");
      printf("WARNING:  If you type in a filename that does not exist, it will crash.\n");
      scanf("%s30", buf);
      
      /* Make sure that file is a valid linked list file. */

      /* Free all the memory. */
      for (temp=list->first; temp->next; temp=temp->next) {

        free(temp->item);

      }
      free(list);

      /* Call the function. */
      list = LoadList(buf);

      /* Set number */
      number = 0;
      for (temp = list->first; temp->next; temp=temp->next) number++;
    
      /* It stops before it should, so add 1. */
      number++;
    
      printinfo();
      break;

    case 'p':
      /* Print the whole list. */
      WriteList(list);
      break;

    case 'q':
      /* Quit. */
      printf("\nGoodbye!\n");
      exit(0);

    case 'r':
      /* Reset the cursor. */
      Reset(list);
      break;

    case 's':
      /* Sort the list. */
      list = quicksort(list);
      WriteList(list);
      break;

    case 'w':
      /* Save list. */
      clearbuf();
      printf("\nEnter a filename.");
      scanf("%s30",buf);
      SaveList(buf, list);
      break;
        
    } /* switch(command) */

  } /* while */

  exit(0);

} /* main */