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

typedef struct Golfer {
   char fName[80];
   char lName[80];
   int handicap;
} Golfer;

typedef struct ListNode {
   Golfer data;
   struct ListNode *next;
} ListNode;


ListNode * findBestGolfer(ListNode *golfers);

ListNode * deletePlayer(ListNode *golfers, ListNode *player);

void printBackward(ListNode *golfers);

void insertInOrder(ListNode **golfers, ListNode *temp);

void printRoster(ListNode *golfers);

//void sortPlayers(Golfer golfers[], int numGolfers);

int main() {
   printf("Hello World!\n");

   Golfer g;
   strcpy(g.fName,"Roger");
   strcpy(g.lName,"Priebe");
   g.handicap = 17;

   printf("%s, %s - %d\n",g.lName, g.fName, g.handicap);

   ListNode *head = NULL;
   ListNode *tail = NULL;

   FILE *fptr;
   fptr = fopen("golfers.dat", "r");

   if (fptr == NULL) {
       printf("Cannot open file!\n");
       exit(0);
   }
   else {
       printf("found it!\n");
       char fName[80];
       char lName[80];
       int handicap;

       while (fscanf(fptr, "%s %s %d",fName, lName, &handicap) != EOF) {
          ListNode *temp = (ListNode *) malloc(sizeof(ListNode));
          strcpy(temp->data.fName,fName);
          strcpy(temp->data.lName, lName);
          temp->data.handicap = handicap;
          temp->next = NULL;

          insertInOrder(&head, temp);
/*
          //O(1) add at end
          if (head == NULL) {
              head = temp;
              tail = temp;
          }
          else {
              tail->next = temp;
              tail = temp;
          }
          
          //O(n) solution to adding at end
          if (head == NULL){  //list is empty?
             head = temp;
          }
          else {
             ListNode *p = head;
             while (p->next != NULL) {
                p = p->next;
             }
             p->next = temp;
          }
*/
  
       }

       printBackward(head);
       printf("---------------------\n");       
       printRoster(head);

       ListNode *bestGolfer = findBestGolfer(head);
       printf("the best golfer is %s\n", bestGolfer->data.fName);
       
       head = deletePlayer(head, bestGolfer);
       printRoster(head);
       printf("----------------------------\n");

       head = deletePlayer(head, head);
       printRoster(head);

       //WARNING MEMORY LEAK
       head = NULL;
       head = deletePlayer(head, head);
       printRoster(head);

       //sortPlayers(golfers, numGolfers);

       //printRoster(golfers, numGolfers); 
    }

       
}

void printBackward(ListNode *golfers) {
   if (golfers != NULL) {
      printBackward(golfers->next);
      printf("%s, %s - %d\n", golfers->data.lName, golfers->data.fName, golfers->data.handicap);
   }
}

//does not account for the tail pointer
void insertInOrder(ListNode **golfers, ListNode *temp) {
   ListNode *p = *golfers;
   ListNode *prev = NULL;

   if (*golfers == NULL) {
      *golfers = temp;
   }
   else {
      while ((p != NULL) && (p->data.handicap < temp->data.handicap)) {
         prev = p;
         p = p->next;   
      }

      if (prev == NULL) {
         temp->next = *golfers;
         *golfers = temp;
      }
      else {
         temp->next = p;
         prev->next = temp;
      }
   }






}





ListNode * deletePlayer(ListNode *golfers, ListNode *player) {

    if (golfers == NULL) {
        return NULL;
    }
    else {
        ListNode *p = golfers;
        ListNode *prev = NULL;

        while((p != NULL) && (p != player)) {
            prev = p;
            p = p->next;
        }

        if (prev == NULL) {  //removing first node in list
            golfers = p->next;
            free(p);
        }
        else if (p == player) {
            prev->next = p->next;
            free(p);
        }
    }

    return golfers;

}

void printRoster(ListNode *golfers) {
   for (ListNode *p = golfers; p != NULL; p = p->next) {
      printf("%s, %s - %d\n", p->data.lName, p->data.fName, p->data.handicap);
   }
}

ListNode * findBestGolfer(ListNode *golfers) {
   if (golfers == NULL) {
      return NULL;
   }
   else {
      ListNode *best = golfers;
      ListNode *p = golfers->next;
      
      while (p != NULL) {
         if (p->data.handicap < best->data.handicap) {
            best = p;
         }

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