--  Programmed by Jedidiah Barber
--  Released into the public domain


pragma Ada_2012;


private with

    Interfaces,
    System;


package Libsndfile.Virtual is


    ---------------------------------
    --  Data Types and Structures  --
    ---------------------------------

    type Virtual_Sound_File is new Sound_File with private;

    type File_Length_Function is access function
        return Count_Type;

    type Seek_Function is access function
           (Offset : in Count_Type;
            Whence : in Seek_From)
        return Count_Type;

    type Read_Function is access function
           (Data  :    out Raw_Data;
            Bytes : in     Count_Type)
        return Count_Type;

    type Write_Function is access function
           (Data  : in Raw_Data;
            Bytes : in Count_Type)
        return Count_Type;

    type Tell_Function is access function
        return Count_Type;




    ---------------------
    --  API Interface  --
    ---------------------

    procedure Open
           (File   : in out Virtual_Sound_File;
            Mode   : in     File_Mode;
            Info   : in out File_Info;
            Length : in     File_Length_Function;
            Seek   : in     Seek_Function;
            Read   : in     Read_Function;
            Write  : in     Write_Function;
            Tell   : in     Tell_Function)
    with Pre => not Is_Open (File),
        Post => Is_Open (File);


private


    type Virtual_Data is limited record
        My_Length : File_Length_Function;
        My_Seek   : Seek_Function;
        My_Read   : Read_Function;
        My_Write  : Write_Function;
        My_Tell   : Tell_Function;
    end record with Convention => C;


    type Virtual_Sound_File is new Sound_File with record
        My_Virtual : Virtual_Data;
    end record;




    function Ada_Filelen_Hook
           (Data : in System.Address)
        return Interfaces.Integer_64;
    pragma Export (C, Ada_Filelen_Hook, "ada_filelen_hook");

    function Ada_Seek_Hook
           (Offset : in Interfaces.Integer_64;
            Whence : in Interfaces.C.int;
            Data   : in System.Address)
        return Interfaces.Integer_64;
    pragma Export (C, Ada_Seek_Hook, "ada_seek_hook");

    function Ada_Read_Hook
           (Ptr   : in System.Address;
            Count : in Interfaces.Integer_64;
            Data  : in System.Address)
        return Interfaces.Integer_64;
    pragma Export (C, Ada_Read_Hook, "ada_read_hook");

    function Ada_Write_Hook
           (Ptr   : in System.Address;
            Count : in Interfaces.Integer_64;
            Data  : in System.Address)
        return Interfaces.Integer_64;
    pragma Export (C, Ada_Write_Hook, "ada_write_hook");

    function Ada_Tell_Hook
           (Data : in System.Address)
        return Interfaces.Integer_64;
    pragma Export (C, Ada_Tell_Hook, "ada_tell_hook");


end Libsndfile.Virtual;