//---------------------------------------------------------------------------
#include <vcl.h>
#pragma hdrstop

#include "FileList.h"
#include "BinaryFile.h"

//---------------------------------------------------------------------------
#pragma package(smart_init)

// list operations

template <class LRecord>
void FileList<LRecord>::Open(AnsiString FileName) // open if existing file, create otherwise
{ ListInfo H;
  BF.Assign(FileName);
  if (FileExists(FileName))
    { BF.Open();
      BF.ReadHeader(H);
      Current = H.Head;
      Previous = -1; }
  else
    { ListInfo H;
      BF.Create();
      H.Head = -1;
      H.DeleteList = -1;
      Current = -1;
      Previous = -1;
      BF.WriteHeader(H); }
}


template <class LRecord>
void FileList<LRecord>::Close() // open if existing file, create otherwise
{ BF.Close();}


template <class LRecord>
void FileList<LRecord>::Insert(LRecord Item) // insert record in order
{ /*int NewRecNo, CurNo, PrevNo;
  ListNode NewRec, Cur, Prev;
  ListInfo H;

  // find file address of new record
  BF.ReadHeader(H);
  if (H.DeleteList != -1)
    { NewRecNo = H.DeleteList;
      BF.Read(Cur, H.DeleteList);
      H.DeleteList = Cur.Next;
      BF.WriteHeader(H); } // if
  else
    NewRecNo = BF.Size();

  // determine location in list of new record and insert
  if (H.Head == -1)
    {H.Head = NewRecNo;
     NewRec.Next = -1;
     StrLCopy((char*)NewRec.item,(char*)Item, sizeof(LRecord));
     BF.Write(NewRec, NewRecNo); } // if
  else
    {PrevNo = -1;
     CurNo = H.Head;
     BF.Read(Cur, CurNo);
     while (Cur.item < Item)
       { PrevNo = Current;
         if (Cur.Next == -1)
           break;
         else
           { Current = Cur.Next;
             Prev = Cur;
             BF.Read(Cur, CurNo);
           { // else
        } // while
     } // else


     if (PrevNo == -1) // insert into head of list
       { NewRec.Next = H.Head;
         StrLCopy((char*)NewRec.item,(char*)Item, sizeof(LRecord));
         H.Head = NewRecNo;
         BF.WriteHeader(H);
         BF.Write(NewRec, NewRecNo);
       } // if
     else // insert into body of list
       { NewRec.Next = CurNo;
         StrLCopy((char*)NewRec.item,(char*)Item, sizeof(LRecord));
         Prev.Next = NewRecNo;
         BF.Write(Prev, PrevNo);
         BF.Write(NewRec, NewRecNo);
       }  // else
 */
}  // insert


template <class LRecord>
void FileList<LRecord>::Search(LRecord &SearchItem) // find first record that is at or after SearchItem
{}

template <class LRecord>
void FileList<LRecord>::GetCurrent(LRecord &Item)  // read current record
{ ListNode LItem;
  BF.Read(LItem, Current);
  Item = LItem.item;}

template <class LRecord>
void FileList<LRecord>::GetNext(LRecord &Item) // read next record
{ if (!this.AtEnd())
    { ListNode temp;
      BF.Read(temp, Current);
      Previous = Current;
      Current = temp.Next;
      BF.Read(temp, Current);
      Item = temp.item; }
}

template <class LRecord>
void FileList<LRecord>::GetFirst(LRecord &Item) // read first record
{ ListNode temp;
  Current = Head;
  Previous = -1;
  BF.Read(temp, Current)
  Item = temp.item;
}

template <class LRecord>
void FileList<LRecord>::Delete() // delete current record
{}

template <class LRecord>
void FileList<LRecord>::ModifyCurrent(LRecord &Item) //rewrite current record
{ ListNode temp;
  BF.Read(temp, Current);
  if (temp.item == Item)
    { temp.item = Item;
      BF.Write(temp, Current); }
  else
    { this.Delete();
      this.Insert(Item); }
}

template <class LRecord>
bool FileList<LRecord>::AtEnd() // true if current is last record in list.
{  ListNode temp;
   BF.Read(temp, Current);
   return (temp.next == -1);}

template <class LRecord>
void FileList<LRecord>::Pack()  // rewrites list with list order in order.
{}