------------------------------------------------------------------------------
--                              Ada Web Server                              --
--                                                                          --
--                            Copyright (C) 2007                          --
--                                 AdaCore                                  --
--                                                                          --
--  This library is free software; you can redistribute it and/or modify    --
--  it under the terms of the GNU General Public License as published by    --
--  the Free Software Foundation; either version 2 of the License, or (at   --
--  your option) any later version.                                         --
--                                                                          --
--  This library is distributed in the hope that it will be useful, but     --
--  WITHOUT ANY WARRANTY; without even the implied warranty of              --
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU       --
--  General Public License for more details.                                --
--                                                                          --
--  You should have received a copy of the GNU General Public License       --
--  along with this library; if not, write to the Free Software Foundation, --
--  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.          --
--                                                                          --
------------------------------------------------------------------------------

with GNAT.Regpat;

with AWS.Translator;

package body AWS.Resources.Streams.Pipe is

   -----------
   -- Close --
   -----------

   overriding procedure Close (Resource : in out Stream_Type) is
   begin
      Expect.Close (Resource.Pid);
   end Close;

   -----------------
   -- End_Of_File --
   -----------------

   overriding function End_Of_File
     (Resource : in Stream_Type) return Boolean is
   begin
      return Resource.EOF;
   end End_Of_File;

   ----------
   -- Open --
   ----------

   procedure Open
     (Pipe    :    out Stream_Type;
      Command : in     String;
      Args    : in     OS_Lib.Argument_List;
      Timeout : in     Integer := 10_000) is
   begin
      Expect.Non_Blocking_Spawn (Pipe.Pid, Command, Args);
      Pipe.EOF := False;
      Pipe.Timeout := Timeout;
   end Open;

   ----------
   -- Read --
   ----------

   overriding procedure Read
     (Resource : in out Stream_Type;
      Buffer   :    out Stream_Element_Array;
      Last     :    out Stream_Element_Offset)
   is
      Regexp : constant Regpat.Pattern_Matcher :=
                 Regpat.Compile (".+", Flags => Regpat.Single_Line);
      Result : Expect.Expect_Match;
   begin
      while Length (Resource.Buffer) < Buffer'Length loop
         begin
            Expect.Expect (Resource.Pid, Result, Regexp, Resource.Timeout);
         exception
            when Expect.Process_Died =>
               Resource.EOF := True;
               exit;
         end;

         case Result is
            when 1 =>
               Append (Resource.Buffer, Expect.Expect_Out (Resource.Pid));

            when Expect.Expect_Timeout =>
               Last := Buffer'First - 1;
               return;

            when others =>
               Last := Buffer'First - 1;
               return;
         end case;
      end loop;

      declare
         L : constant Natural := Length (Resource.Buffer);
      begin
         if Buffer'Length >= L then
            Last := Buffer'First + Stream_Element_Offset (L) - 1;
            Buffer (Buffer'First .. Last) :=
              Translator.To_Stream_Element_Array (To_String (Resource.Buffer));
            Resource.Buffer := Null_Unbounded_String;

         else
            Buffer := Translator.To_Stream_Element_Array
              (Slice (Resource.Buffer, 1, Buffer'Length));
            Last := Buffer'Last;
            Delete (Resource.Buffer, 1, Buffer'Length);
         end if;
      end;
   end Read;

end AWS.Resources.Streams.Pipe;
