#include<stdio.h>
#include<string.h>
#include<stdlib.h>

typedef struct gorivo_st{

	char oznaka[3];
	char tip[11];
	double cena;
	struct gorivo_st *next;

}node;

void insert(node ** root, char oznaka[],char tip[], double cena){

	node* newNode = (node*)malloc(sizeof(node));
	strcpy(newNode->oznaka,oznaka);
	strcpy(newNode->tip, tip);
	newNode->cena = cena;
	newNode->next = NULL;

	if(*root == NULL){
		*root = newNode;
	}else{
		newNode->next = *root;
		*root = newNode;
	}

}

void insertNaKraj(node ** root, char oznaka[],char tip[], double cena){
	node* newNode = (node*)malloc(sizeof(node));
	strcpy(newNode->oznaka,oznaka);
	strcpy(newNode->tip, tip);
	newNode->cena = cena;
	newNode->next = NULL;
	node * current = *root;
	if(*root == NULL){
		*root = newNode;
		return;
	}
	while(current->next == NULL){
		current = current->next;
	}
	current->next= newNode;
}
void printList(node * root){

	node* current = root;
	while(current != NULL){
		printf("%lf %s %s\n",current->cena,current->oznaka,current->tip);
		current = current->next;
	}
}

void ucitajIzFajla(char imeFajla[], node ** root){

	FILE *f = fopen(imeFajla,"r");
	if(f==NULL){
		printf("Greska prilikom otvaranja ulaznog fajla");
		exit(1);
	}
	char oznaka[3];
	char tip[11];
	double cena;
	while(fscanf(f,"%s %s %lf\n",oznaka,tip,&cena) != EOF){
		insert(root,oznaka,tip,cena);
	}
	fclose(f);
}

void obrisiListu(node** root){
	node* temp = *root;
	while(*root!=NULL){
		temp = *root;
		*root = (*root)->next;
		//printf("Brisem: %lf %s %s\n",temp->cena,temp->oznaka,temp->tip);
		free(temp);
	}
	*root=NULL;
}

node* nadjiNajeftinije(node* root){

	node* min = root;
	node* current = root;

	while(current != NULL){
		if(min->cena > current->cena)
			min=current;
		current = current->next;
	}
	return min;
}

node* getAt(node * root, int pos){	//pronalazi cvor na odredjenoj poziciji
	int i = 0;
	node * current = root;
	while(i != pos && current != NULL){
		current = current->next;
		i++;
	}
	return current;
}

void deleteNode(node ** root, node* zaBrisanje){

	if(*root ==NULL){   //ukoliko je lista prazna
		return;
	}
	if(*root == zaBrisanje){	//ukoliko je cvor za brisanje prvi cvor u listi
		*root = zaBrisanje->next;
		free(zaBrisanje);
	}
	//iteratori
	node* current = *root;
	node* previous;

	//iteriramo kroz listu dok ne dodjemo do kraja ili dok ne nadjemo cvor za brisanje
	while(current != NULL && current != zaBrisanje){
		previous = current;
		current = current->next;
	}
	if(current != NULL){ // ukoliko smo nasli radimo prevezivanje
		previous->next = current->next;
		free(current);
	}
}

float average(node * root){
	node * current = root;
	float sum=0;
	int count=0;
	while(current != NULL){
		sum = sum + current->cena;
		count = count + 1;
		current = current->next;
	}
	return sum/count;
}
float averageZaTip(node * root,char tip[]){
	node * current = root;
	float sum=0;
	int count=0;
	while(current != NULL){
		if(strcmp(current->tip,tip)==0){
			sum = sum + current->cena;
			count = count + 1;
		}
		//ovo obavezno izvan if-a
		current = current->next;
	}
	if(count == 0){
		return -1;
	}
	return sum/count;
}

void ispisiVeceOdProsecene(node * root,float prosecna){
	node * current = root;

	while(current != NULL){
		if(current->cena > prosecna){
			printf("%s %f\n",current->tip,current->cena);
		}
		current = current->next;
	}
}

void ispisiVeceOdProsecenePoTipu(node * root,float prosecna,char tip[]){
	node * current = root;

	while(current != NULL){
		if(current->cena > prosecna && strcmp(current->tip,tip)==0){
			printf("%s %f\n",current->tip,current->cena);
		}
		current = current->next;
	}
}


void main(){

	node * root = NULL;
	ucitajIzFajla("cene.txt",&root);
	printList(root);
	node* najeftiniji = getAt(root,4);

	printf("gorivo  %lf %s %s\n",
		najeftiniji->cena,najeftiniji->oznaka,najeftiniji->tip);
	float prosecna = average(root);
	float prosecnaGas = averageZaTip(root,"kerozin");
	printf("Vece od prosecne\n***********************\n");
	ispisiVeceOdProsecene(root,prosecna);

	printf("Vece od prosecne\n***********************\n");
	if(prosecnaGas == -1){
		printf("NOT FOUND(nema tog goriva");
	}else{
		printf("\nprosecna cena gorivaa je %f\n",prosecnaGas);
	}

	//deleteNode(&root,najeftiniji);
	printf("Nakon brisanja :\n");
	printList(root);

	obrisiListu(&root);
}