//Filename: showtree.c
//Developer: Jay Suttiruttana

#include "btree.h"

void main(void)
{
   //opens the B-Tree file
	btopen();

printf("B-Tree:\n\n");
//printf("PAGE FORMAT -> [p0,(PK0),p1,(PK1),p2,(PK2),p3,(PK3),p4]\n\n");
   /* pass in the root of the B-Tree */
	ShowTree( getroot() );

   //close the B-Tree file
	btclose();
}

/*******************************************************************************
Function: ShowTree
Return type: an integer
Task: it it outputs the B-Tree data structure--displaying all pages in the tree.
Pre: the rrn has been passed in succesfully.
Post: the structure of the B-Tree passed in is output on the screen. In successful
      of doing that, it returns 1.  Otherwise, returns 0.
*******************************************************************************/

int ShowTree(int rrn)
{
	page_type page;
	int     i;

	if(rrn == NIL)
		return(0);

	btread(rrn, &page);  /* Retrieve current page from B-Tree      */

	printf("PAGE #%d -> ", rrn); /* Display current page # and the page itself */
    if(rrn < 10) printf("   ");
	if(rrn>=10 && rrn<100) printf("  ");
	if(rrn>=100) printf(" ");
		ShowPage(&page);

	for(i=0; i<=page.keycount&&page.child[i]!=NIL;i++)
		ShowTree(page.child[i]);   		/* Show each page in B-Tree */
	return(1);
}


/*******************************************************************************
Function: ShowPage
Return type: none
Task: it it outputs all keys and descendents' RRNs of the given page.
Pre: the page is passed in.
Post: all keys and descendents' RRNs of the given page are output.
*******************************************************************************/

void ShowPage(page_type *p_page)
{
  int i;

  /* display each key & left child in page */
  printf("[");
  for(i=0;i<p_page->keycount;i++)
	printf("%2d,(%3d),", p_page->child[i], p_page->item[i].key);

  /* display the last child in page   */
  printf("%2d]\n", p_page->child[i]);
}

/*******************************************************************************/