#include "file.h"
/* how we print your linked list to test if it is correct or not*/
void print(){
	node *ptr = head;
	while(ptr != NULL){
                printf("%d->",ptr->data);
                ptr = ptr->next;
        }
	printf("\n");
}
/* function to add a node to the list for you use in fwrite*/
void append(node * n){
	n->next = head->next;
	head->next = n;
}
/*function to get the last node for you to allow you to save it a file*/
node * getLast(){
	if(!head->next){
		return NULL;	
	}
	node * ptr = head->next->next; 
	node * tmp = head->next;
	node * prev = head;
	while(ptr != NULL){
		prev = tmp;	
		tmp = ptr;
		ptr = ptr->next;
	}
	prev->next = NULL;
	return tmp;	
}
/* read a node from file until you reach an EOF. Each node you read please save to the linked list with append()*/ 
void read_node(char * filename){
	FILE* in = fopen(filename, "rb");

	node* item = (node *) malloc(sizeof(node));
	int bytesRead = fread(item, sizeof(node), 1, in);
	while (bytesRead > 0) {
		append(item);
		
		item = (node *) malloc(sizeof(node));
		bytesRead = fread(item, sizeof(node), 1, in);
	}

	fclose(in);
}

/* USING get last keep writing to file until getLast() returns NULL
 * Please use fwrite in binary mode to do this
 * Make sure that you are setting node->next = NULL*/
void write_node(char * filename){
	FILE* out = fopen(filename, "wb");

	node* item = getLast();
	while (item != NULL) {
		item->next = NULL;

		fwrite(item, sizeof(node), 1, out);
		
		free(item);
		item = NULL;

		item = getLast();
	}
	
	fclose(out);
}