#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "studlist10.h"

int main()
{
  char *filename="Student.txt";
  FILE *fp;
  Record r;
  char selstr[20];
 
  /* initialize */
  head = make_1node( r, NULL );

  /* input data from file */
  if ((fp = fopen(filename, "r")) == NULL) {
    fprintf(stderr, "Cannot open %s!\n", filename);
    exit(1);
  }

  while (fscanf(fp, "%d %s %s %d", &r.id, r.surname, r.givenname, &r.age) != EOF) {
    if(insert(r) == NULL) printf("Error: %d appears twice in the file.\n", r.id);   /* ここのメッセージは適当。なくてもよい */
  }
  fclose(fp);
  listprint();


  /* insert list member */
  /* CTL+D to escape this loop */
  while (1) {
    printf("Input match data (ID) -> ");
    if (scanf("%s", selstr) != 1) {
      printf("\n");
      break;
    }
    listprint_sel(selstr);
  }
  return 0;
}

/* First, find item r, based on data ID */
/* If the ID is not found, insert r after the last node */
/* Return value: node(inserted), NULL(already exist) */
NodePointer insert(Record r)
{
  NodePointer newnode, n;

  if (finditem(r.id) == NULL) {
    /* new node creation (if the item is not found) */
    newnode = make_1node(r, NULL);

    /* trace nodes from head to tail */
    for ( n=head; n->next!=NULL; n=n->next );
    
    n->next = newnode;   /* link new node to the last node */
    return newnode;
  }
  else return NULL;
}

/* print all items in the list from head to tail */
void listprint(void)
{
  NodePointer n;
  int count = 0;

  printf("Head - \n");
  for(n = head->next; n != NULL; n = n->next){
    printf("  %7d %-12s %-12s %d\n", n->data.id, n->data.surname, n->data.givenname, n->data.age);
    count++;
  }
  printf("%d nodes exist in the list.\n", count);
  printf("\n");
}

/* find item id_data with given ID                      */
/*   if found, return the address of the previous node. */
/*   otherwise, return NULL                             */
NodePointer finditem(int sid)
{
  NodePointer n;
  
  for(n = head; n->next != NULL; n = n->next) {
    if(n->next->data.id == sid) return n;
  }
  return NULL;
}

NodePointer make_1node(Record r, NodePointer p)
{
  NodePointer n;

  if ((n = (NodePointer) malloc(sizeof(struct node)) ) == NULL) {
    printf("Error in memory allocation\n");
    exit(8);
  }

  n->data = r;
  n->next = p;
  return n;
}

/* print all items in the list from head to tail */
void listprint_sel(char *str)
{
  NodePointer n;
  char numstr[20];
  
  for(n = head->next; n != NULL; n = n->next){
      sprintf(numstr, "%d", n->data.id);
      if (strncmp(numstr, str, strlen(str))==0) {
          printf("  %7d %-12s %-12s %d\n", n->data.id, n->data.surname, n->data.givenname, n->data.age);
      }
  }
  printf("\n");
}