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

#define MAX_SIMBOL 2+1
#define MAX_IME 20+1
#define MAX_VRSTA 20+1

typedef struct element_st{
    char simbol[MAX_SIMBOL];
    char ime[MAX_IME];
    unsigned tezina;
    char vrsta[MAX_VRSTA];

    struct element_st *next;
} ELEMENT;

void init_list(ELEMENT **head){
    *head=NULL;
}

FILE *file_sopen(char filename[], char mode[], int error_code){
    FILE *fp=fopen(filename,mode);
    if(fp==NULL){
    printf("Niste uspeli da otvorite fajl %s", filename);
    exit(error_code);
    }
    return fp;
}

ELEMENT* kreiraj_novi_item(char simbol[],char ime[],unsigned tezina,char vrsta[]){
    ELEMENT *new=(ELEMENT *)malloc(sizeof(ELEMENT));
    if(new==NULL){
    exit(21);
    }

    strcpy(new->simbol, simbol);
    strcpy(new->ime, ime);
    new->tezina=tezina;
    strcpy(new->vrsta, vrsta);

    new->next=NULL;

    return new;
}

void add_to_list(ELEMENT *new,ELEMENT **head){
    if(*head == NULL) { // list is empty
        *head = new;
        return;
    }

    add_to_list(new, &((*head)->next));
}


void read_list_from(FILE *in,ELEMENT **head){
    char simbol[MAX_SIMBOL];
    char ime[MAX_IME];
    unsigned tezina;
    char vrsta[MAX_VRSTA];

    while(fscanf(in,"%s %s %u %s",simbol, ime, &tezina, vrsta)!=EOF){
    ELEMENT *new=kreiraj_novi_item(simbol,ime,tezina,vrsta);
    add_to_list(new,head);
    }
}
void save_item_to(FILE *out, ELEMENT *x){
    fprintf(out, "%-2s %3u %s \n",
    x->simbol, x->tezina, x->vrsta);

}

void save_list_to(FILE *out,ELEMENT *head){
    if(head !=NULL){
    save_item_to(out, head);
    save_list_to(out, head->next);
}
}



void destroy_list(ELEMENT **head){
    if(*head!=NULL){
    destroy_list(&((*head)->next));
    free(*head);
    *head=NULL;
    }
}

ELEMENT *nadji_najbolji(ELEMENT *head,char vrsta[]){
if(head==NULL){
    return NULL;}
ELEMENT *best=NULL;
while(head!=NULL){
    if(strcmp(head->vrsta,vrsta)==0){
    if(best==NULL)
    best=head;
    else if(head->tezina>best->tezina)
    best=head;
    }

    head=head->next;
}
return best;
}

int main(int arg_num, char *args[]){

if(arg_num!=4){
    printf("Niste lepo pokrenuli program.");
    exit(212);
}

char *vrsta=args[1];
char *in_filename=args[2];
char *out_filename=args[3];

FILE *in=file_sopen(in_filename, "r", 1);
FILE *out=file_sopen(out_filename, "w", 2);

ELEMENT *head;
init_list(&head);

read_list_from(in, &head);
save_list_to(out, head);

ELEMENT *best=nadji_najbolji(head,vrsta);
if (best == NULL) {
        fprintf(out, "\nU uzorku nije pronadjen nijedan %s!\n", vrsta);
    } else {
        fprintf(
            out, "\nNajtezi %s je %s (%s), atomska tezina %u\n",
            best->vrsta, best->ime, best->simbol, best->tezina
        );
    }

destroy_list(&head);

fclose(in);
fclose(out);

return 0;}