#include <stdlib.h>
#include "node.h"

node_t *node_create(void *data) {
	node_t *temp = malloc(sizeof(node_t));

	temp->data = data;
	temp->left = temp->right = NULL;

	return temp;
}

node_t *node_search(node_t *root, void *data, node_comparator func) {
	int cmp;
	if (root == NULL) {
		return root;
	}

	node_t *temp = node_create(data);
	cmp = func(root, temp);
	free(temp);

	if (cmp == 0) {
		return root;
	}

	if (cmp < 0) {
		return node_search(root->left, data, func);
	} else {
		return node_search(root->right, data, func);
	}
}

node_t *node_insert(node_t *node, void *data, node_comparator func) {
	if (node == NULL) {
		return node_create(data);
	}

	node_t *temp = node_create(data);
	int cmp = func(node, temp);
	free(temp);

	if (cmp < 0) {
		node->left = node_insert(node->left, data, func);
	} else {
		node->right = node_insert(node->right, data, func);
	}
	return node;
}

node_t *node_find_leftmost(node_t *root) {
	if (root == NULL) {
		return NULL;
	} else if (root->left != NULL) {
		return node_find_leftmost(root->left);
	}
	return root;
}

node_t *node_remove(node_t *root, void *data, node_comparator func) {
	if (root == NULL) {
		return NULL;
	}
	node_t *temp = node_create(data);
	int cmp = func(root, temp);
	free(temp);

	if (cmp > 0) {
		root->right = node_remove(root->right, data, func);
	} else if (cmp < 0) {
		root->left = node_remove(root->left, data, func);
	} else {
		if ((root->left == NULL) && (root->right == NULL)) {
			free(root);
			return NULL;
		} else if ((root->left == NULL) || (root->right == NULL)) {
			if (root->left == NULL) {
				temp = root->right;
			} else {
				temp = root->left;
			}
			free(temp);
		} else {
			temp = node_find_leftmost(root->right);
			root->data = temp->data;
			root->right = node_remove(root->right, temp->data, func);
		}
	}
	return root;
}