[Ident('2.0'), INHERIT ('SYS$LIBRARY:STARLET')]
Program Remind(Output);
{ Calendar reminder program
  Copyright © 1989,1990,1991 Bruce Tanner - Cerritos College }

{ This is essentially a cut down version of Datebook that runs in the background
  and reminds you when there is an entry that matches the current date/time }

%Include 'DBType.PAS'

Const
  Major_Version = 2;
  Minor_Version = 2;
  Remind_1 = 10;	{ First warning at 10 minutes }
  Remind_2 = 5;		{ Second warning at 5 minutes }

Var
  { Dates }
  Null_Date,		{ A constant record }
  Todays_Date, Load_Date: D_Type;
  Null_Time: T_Type;

{ DB_Date routines }
Procedure Date_Init; Extern;
Function Same_Date(Date1,Date2: D_Type): Boolean; Extern;
Function Parse_Date(PL: String; W_Date: D_Type; Var R_Date: D_Type): Boolean; Extern;

{ DB_DB routines }
Procedure DB_Init; Extern;
Function First(LT: List_Type): H_Ptr; Extern;
Function Next(LT: List_Type; Ptr: H_Ptr): H_Ptr; Extern;
Procedure Store_Cal(T_Date: D_Type); Extern;
Procedure Purge(P_List: List_Type); Extern;
Procedure Make_Handle(List: List_Type; Var Rec: Cal_Rec; Key: ID_Type); Extern;

{ DB_FIO routines }
Function Open_Calendar(Which_Cal: Whose_Cal; Index: Integer): Boolean; Extern;
Procedure Load_Handles; Extern;
Function List_Current: Boolean; Extern;

{ DB_VMS Routines }
Procedure Sleep(Length: Real); Extern;
Procedure Get_Today(Var Todays_Date: D_Type); Extern;
Function Get_Now: Integer; Extern;
Procedure Get_Directory(Var Dir: String); Extern;

{ DB_Str Routines }
Procedure Str_Init; Extern;


{ ############################## }
{ Init tables of dates, etc. }

Procedure Main_Init;
Var
  Dir_Name: String;
  Ptr: H_Ptr;
  Did_Header: Boolean;

Begin
  Date_Init;
  DB_Init;
  Str_Init;

  Get_Today(Todays_Date);

  Null_Date.Year := 0;			{ Make record type constants }
  Null_Date.Month := 0;
  Null_Date.Day := 0;

  Did_Header := False;

  If Open_Calendar(Own_Cal, -1) then
    Load_Handles;			{ Load the index pointers (handles) }

  If (First(C_List) = Nil) then	Begin	{ If no entries }
    Load_Date := Todays_Date;
    Store_Cal(Todays_Date)		{ Load up current date's entries }
    End;
  Ptr := First(C_List);
  While Ptr <> Nil do Begin
    If (Ptr^.Start_Time = 9999) { 2.2 non-timed }
        or (Ptr^.Start_Time = 0000) { 2.2 or all day } then Begin
      If Not Did_Header then Begin
        Writeln('Things to do:');
        Did_Header := True
        End;
      Writeln(Ptr^.Message)
      End;
    Ptr := Next(C_List, Ptr)
    End;
End; { Main_Init }


{ Send a message if the terminal is receiving system messages }
Procedure Display_Entry(Handle: H_Rec);

Var
  Result: Integer;
  Message: Varying [100] of Char;

Begin
  Writev(Message, Chr(7), '[Remind: ', Handle.Message, ']');
  Result := $BRKTHRUW(, Message, 'SYS$OUTPUT', BRK$C_DEVICE,,,, BRK$C_USER1,,,);
End;


{ ############################## }
{ Check_Loop displays those entries that match Todays_date and Now }
Procedure Check_Loop;
Var
  D_Date: String;
  Ptr: H_Ptr;
  Now_HHMM, Now_Minutes, Start_Minutes: Integer;

Begin
  Get_Today(Todays_Date);
  IF Not Same_Date(Load_Date,Todays_Date) then  Begin { If entries are not current }
    Load_Date := Todays_Date;
    Store_Cal(Todays_Date)	{ Purge old entries, load up current ones }
    End;
  Ptr := First(C_List);
  Now_HHMM := Get_Now;	{ Return minutes since midnight }
  Now_Minutes := (Now_HHMM DIV 100) * 60 + (Now_HHMM MOD 100);
  While (Ptr <> Nil) do Begin
    Start_Minutes := (Ptr^.Start_Time DIV 100) * 60 + (Ptr^.Start_Time MOD 100);
    If (Ptr^.Check in [' ','R']) { Only regular and recurr are displayed }
        and (Ptr^.End_Time <> 9999) { 2.2 Don't remind 'All Day' at midnight }
        and ((Now_Minutes + Remind_1 = Start_Minutes)
          or (Now_Minutes + Remind_2 = Start_Minutes)
          or (Now_Minutes = Start_Minutes)) then
      Display_Entry(Ptr^);
    Ptr := Next(C_List,Ptr);
    End;
End; { Check_Loop }


{ ############################## }
Procedure Wait_For_Update;
Begin
  Sleep(60);
  If Not List_Current then Begin
    Purge(C_List);
    Purge(R_List);
    Load_Handles;			{ And load the new calendar file }
    Load_Date := Null_Date		{ 2.1 Force a reload of C_List }
    End
End;


Begin { Main }
  Main_Init;		{ Initialize everything }
  Repeat
    Wait_For_Update;	{ Sleep, wait for update or timeout }
    Check_Loop		{ Display messages }
  Until False		{ Forever }
End. { Main }