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

typedef struct litem_t {
    char *orderno;
    char *name;
    float price;
    int count;
} litem;

typedef struct llist_t {
    struct litem_t *item;
    struct llist_t *next;
} llist;



llist *addItem(llist * alist, char *orderno, char *name, float price,
	       int count, float sum)
{

    if (alist == NULL) {	// neue liste anlegen!
	alist = (llist *) calloc(1,sizeof(llist));
	alist->next = NULL;
    } else {
	llist *newlist = (llist *) calloc(1,sizeof(llist));
	newlist->next = alist;
	alist = newlist;
    }
    alist->item = (litem *) calloc(1,sizeof(litem));
    alist->item->orderno = strdup(orderno);
    alist->item->name = strdup(name);
    alist->item->price = price;
    alist->item->count = count;
    if (price * count != sum) {
	printf("error: price * count != sum \n");
    }

    return alist;
}


void dumpList(llist * alist)
{

    while (alist != NULL) {
	printf("%18s %40s %8.2f %03i %8.2f\n",
	       alist->item->orderno,
	       alist->item->name,
	       alist->item->price,
	       alist->item->count,
	       alist->item->count * alist->item->price);
	alist = alist->next;
    }
}

void getSumAndCounter(llist * alist, float *sum, int *count)
{

    while (alist != NULL) {
	*sum += (alist->item->count * alist->item->price);
	*count += alist->item->count;
	alist = alist->next;
    }
}

#define BUFSIZE 1024

char* getstrdelim(char delim, FILE *pFile){
       
	char* buf = calloc(BUFSIZE,sizeof(char)); 
	size_t pos=0;
	while (pos<BUFSIZE){
      buf[pos] = fgetc(pFile);
	  if (buf[pos]==delim || feof(pFile)!=0 ){
		  if (pos==0){
			  free(buf);
			  return NULL;
		  }
		  buf[pos]='\0';

		  //remove leading and trailing spaces:
		 size_t start=0; size_t end=pos;

		  int c=0;
		  while(start<end && c < pos){
			  if (buf[start]==' '){
				  start++;
			  }
			  if (buf[end-1]==' '){
				  end--;
			  }
			  c++;
		  }

          buf[end]='\0';
		  char *ret = strdup(buf+start);


		  free(buf);
		  return ret;
	  }
	  pos++;
	}
    return NULL;

}

llist *readFile(const char *filename, llist * alist)
{

    FILE *pFile = fopen(filename, "r");
    if (NULL == pFile) {
	  fprintf(stderr, "cannot open file %s \n", filename);
	  return alist;
    } else {
	char *buf = NULL;
    size_t r=0; 
    int token=0;
	char* orderno = NULL;
	char* name = NULL;
    float price=0;
	int count=0;
    char delim = ',' ;
    float sum=0;

	while(buf = getstrdelim(delim,pFile)){
          
		  switch(token){
			  	case 0: orderno=strdup(buf);
		                token++;
						break;
			  	case 1: name=strdup(buf);
		                token++;
						break;
				case 2: price = strtof(buf, NULL);
		                token++;
						break;
				case 3: count = strtol(buf, NULL, 10);
						delim='\n';
		                token++;
						break;
                case 4: sum = strtof(buf, NULL);
		                delim=','; //reset delimiter.
						token=0;
						if (sum!=count*price){
							fprintf(stderr,"Error: Sum != count*price: %s \n",orderno);
						}
						alist = addItem(alist,orderno,name,price,count,sum);
						free (orderno);
						free (name);
						orderno=NULL;
						name=NULL;
						break;
		  }
		  free(buf);
	}

	free(orderno);
	free(name);

    }

    fclose(pFile);
    return alist;
}

int main(int argc, char **argv)
{

    llist *alist;
    alist = readFile("bestellung.csv", alist);

    float sum = 0;
    int count = 0;
    getSumAndCounter(alist, &sum, &count);

    dumpList(alist);

    printf("%03i Artikel zum Gesamtpreis von %8.2f\n\n", count, sum);

}