#include <string.h>
#include "stack.h"
#include "bintree.h"
#include <stdio.h>

StackNode *stackRoot = NULL;//Generates a new, empty stack for next tree data

//TODO: binären Suchbaum implementieren
/*  * `addToTree`: fügt ein neues Element in den Baum ein (rekursiv),
    * `clearTree`: gibt den gesamten Baum frei (rekursiv),
    * `treeSize`: zählt die Knoten im Baum (rekursiv),
    * `nextTreeData`: Traversierung mit Hilfe des zuvor implementierten Stacks. */

// Adds a copy of data's pointer destination to the tree using compareFct for ordering. Accepts duplicates
// if isDuplicate is NULL, otherwise ignores duplicates and sets isDuplicate to 1 (or to 0 if a new entry is added).
TreeNode *addToTree(TreeNode *root, const void *data, size_t dataSize, CompareFctType compareFct, int *isDuplicate)
{
	if(!root)
	{
		//root = malloc(sizeof(TreeNode));
		TreeNode *newNode = malloc(sizeof(TreeNode));
		newNode->data = malloc(dataSize);
		newNode->left = NULL;
		newNode->right = NULL;
		strcpy(newNode->data, data);
		if(isDuplicate)
			*isDuplicate = 0;
		return newNode;
	}
	if(compareFct(data, root->data) > 0)
	{
		root->right = addToTree((root->right), data, dataSize, compareFct, isDuplicate);
	}
	else if(compareFct(data, root->data) < 0)
	{
		root->left = addToTree((root->left), data, dataSize, compareFct, isDuplicate);
	}
	else
	{
		if(!isDuplicate)
			root->left = addToTree(root->left, data, dataSize, compareFct, isDuplicate);
		else
		{
			*isDuplicate = 1;
		}
	}
	return root;
}

// Iterates over the tree given by root. Follows the usage of strtok. If tree is NULL, the next entry of the last tree given is returned in ordering direction.
// Use your implementation of a stack to organize the iterator. Push the root node and all left nodes first. On returning the next element,
// push the top node and push all its left nodes.
void *nextTreeData(TreeNode *root)
{
	if(root)
	{
		stackRoot = push(root->data, stackRoot);
		nextTreeData(root->left);
		nextTreeData(root->right);
	}
	return stackRoot;
}


// Releases all memory resources (including data copies).
void clearTree(TreeNode *root)
{
	if(root->left)
		clearTree(root->left);
	if(root->right)
		clearTree(root->right);
	free(root->data);
	root->data = NULL;
	free(root);
	root = NULL;
}

// Returns the number of entries in the tree given by root.
unsigned int treeSize(const TreeNode *root)
{
	if(root)
	{
		unsigned int tempSize = 0;
		if(root->left)
			tempSize += treeSize(root->left);
		if(root->right)
			tempSize += treeSize(root->right);
		return tempSize + 1;
	}
	return 0;
}