------------------------------------------------------------------------------
--                     XML/Ada - An XML suite for Ada95                     --
--                                                                          --
--                     Copyright (C) 2001-2012, AdaCore                     --
--                                                                          --
-- This library is free software;  you can redistribute it and/or modify it --
-- under terms of the  GNU General Public License  as published by the Free --
-- Software  Foundation;  either version 3,  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 MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE.                            --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
--                                                                          --
-- You should have received a copy of the GNU General Public License and    --
-- a copy of the GCC Runtime Library Exception along with this program;     --
-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
-- <http://www.gnu.org/licenses/>.                                          --
--                                                                          --
------------------------------------------------------------------------------

with Unicode;           use Unicode;
with Unicode.CES;       use Unicode.CES;
with Unicode.CES.Utf32; use Unicode.CES.Utf32;
with Unicode.CES.Utf16; use Unicode.CES.Utf16;
with Unicode.CES.Utf8;  use Unicode.CES.Utf8;

package body Input_Sources.Strings is

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

   procedure Open
     (Str      :     Unicode.CES.cst_byte_sequence_access;
      Encoding :     Unicode.CES.encoding_scheme;
      Input    : out string_input)
   is
      BOM : bom_type;
   begin
      Input.Encoding := Encoding;
      Input.Buffer   := Str;
      Input.Buffer2  := null;
      Input.Index    := Input.Buffer'first;

      Read_Bom (Input.Buffer.all, Input.Prolog_Size, BOM);
      case BOM is
         when utf32_le =>
            Set_Encoding (Input, Utf32_LE_Encoding);
         when utf32_be =>
            Set_Encoding (Input, Utf32_BE_Encoding);
         when utf16_le =>
            Set_Encoding (Input, Utf16_LE_Encoding);
         when utf16_be =>
            Set_Encoding (Input, Utf16_BE_Encoding);
         when ucs4_be | ucs4_le | ucs4_2143 | ucs4_3412 =>
            raise Invalid_Encoding;
         when utf8_all | unknown =>
            Set_Encoding (Input, Utf8_Encoding);
      end case;
   end Open;

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

   procedure Open
     (Str      :     Unicode.CES.byte_sequence;
      Encoding :     Unicode.CES.encoding_scheme;
      Input    : out string_input)
   is
      BOM : bom_type;
   begin
      Input.Encoding := Encoding;
      Input.Buffer2  := new byte_sequence'(Str);
      Input.Buffer   := cst_byte_sequence_access (Input.Buffer2);
      Input.Index    := Input.Buffer'first;

      Read_Bom (Input.Buffer.all, Input.Prolog_Size, BOM);
      case BOM is
         when utf32_le =>
            Set_Encoding (Input, Utf32_LE_Encoding);
         when utf32_be =>
            Set_Encoding (Input, Utf32_BE_Encoding);
         when utf16_le =>
            Set_Encoding (Input, Utf16_LE_Encoding);
         when utf16_be =>
            Set_Encoding (Input, Utf16_BE_Encoding);
         when ucs4_be | ucs4_le | ucs4_2143 | ucs4_3412 =>
            raise Invalid_Encoding;
         when utf8_all | unknown =>
            Set_Encoding (Input, Utf8_Encoding);
      end case;
   end Open;

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

   procedure Close (Input : in out string_input) is
   begin
      if Input.Buffer2 /= null then
         Free (Input.Buffer2);
      end if;
      Input_Sources.Close (input_source (Input));
   end Close;

   ---------------
   -- Next_Char --
   ---------------

   procedure Next_Char
     (From : in out string_input;
      C    :    out Unicode.unicode_char)
   is
   begin
      From.Encoding.Read (From.Buffer.all, From.Index, C);

   exception
      --  For a String input, an incomplete encoding is invalid.
      when Incomplete_Encoding =>
         raise Invalid_Encoding;
   end Next_Char;

   ---------
   -- Eof --
   ---------

   function Eof (From : string_input) return Boolean is
   begin
      return From.Index > From.Buffer'last;
   end Eof;

end Input_Sources.Strings;