#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;

litem *newItem( char *orderno, char *name, float price,int count){
	litem *item = (litem *) calloc(1,sizeof(litem));
    item->orderno = strdup(orderno);
	item->name = strdup(name);
	item->price = price;
	item->count = count;
    return item;
}

void update_item(litem *item,char *orderno, char *name, float price,int count){
	item->count+=count;
}


llist *addItem(llist * alist, char *orderno, char *name, float price,
	       int count, float sum)
{
   if (alist == NULL ) {
	   alist = (llist *) calloc(1,sizeof(llist));
	   alist->next = NULL;
	   alist->item = newItem(orderno,name,price,count);
	   return alist; //start der Liste
   }
   llist *current=alist;
   //suchen ob item schon in der liste:
   while (current->next != NULL){
       if (0==strcmp(current->item->orderno,orderno)){
		   update_item(current->item,orderno,name,price,count);
		   return alist;
	   }
	   current=current->next;
   }

  if (0==strcmp(current->item->orderno,orderno)){
   update_item(current->item,orderno,name,price,count);
   return alist;
  }

  //nicht gefunden, also neu anhaengen:
  
	current->next = (llist *) calloc(1,sizeof(llist));
	current->next->next = NULL;
    current->next->item = newItem(orderno,name,price,count);

   return alist;
}




void dumpList(llist * alist)
{
    printf("\n%18s           %-30s %8s %3s %8s\n", "OrderNo.","Name","EP","#","GP");
    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;
    }
	printf("\n");
}

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);
    } 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)
{

	if (argc<2){
		fprintf(stderr,"Fehler: Dateiname angeben!\n");
		exit(1);
	}

    llist *alist;
    alist = readFile(argv[1], 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);

}