(*
    Copyright 2016, 2017 Anton Krotov

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*)

MODULE API;

IMPORT sys := SYSTEM;

VAR

  Alloc*: PROCEDURE [winapi] (uFlags, dwBytes: INTEGER): INTEGER;
  Free*: PROCEDURE [winapi] (hMem: INTEGER): INTEGER;
  MessageBoxA*: PROCEDURE [winapi] (hWnd, lpText, lpCaption, uType: INTEGER): INTEGER;
  ExitProcess*: PROCEDURE [winapi] (code: INTEGER);
  ExitThread*: PROCEDURE [winapi] (code: INTEGER);
  GetCurrentThreadId*: PROCEDURE [winapi] (): INTEGER;
  strncmp*: PROCEDURE [cdecl] (a, b, n: INTEGER): INTEGER;

  GetProcAddress*: PROCEDURE [winapi] (hModule, name: INTEGER): INTEGER;
  LoadLibraryA*: PROCEDURE [winapi] (name: INTEGER): INTEGER;

PROCEDURE zeromem*(size, adr: INTEGER);
END zeromem;

PROCEDURE DebugMsg*(lpText, lpCaption: INTEGER);
BEGIN
  MessageBoxA(0, lpText, lpCaption, 16)
END DebugMsg;

PROCEDURE GetProc(name: ARRAY OF CHAR; hMOD, adr: INTEGER);
VAR H: INTEGER;
BEGIN
  H := GetProcAddress(hMOD, sys.ADR(name[0]));
  ASSERT(H # 0);
  sys.PUT(adr, H);
END GetProc;

PROCEDURE _NEW*(size: INTEGER): INTEGER;
  RETURN Alloc(64, size)
END _NEW;

PROCEDURE _DISPOSE*(p: INTEGER): INTEGER;
  RETURN Free(p)
END _DISPOSE;

PROCEDURE init* (esp: INTEGER);
VAR lib: INTEGER;
BEGIN
  sys.GET(esp, GetProcAddress);
  sys.GET(esp + 4, LoadLibraryA);

  lib := LoadLibraryA(sys.ADR("kernel32.dll"));
  GetProc("ExitProcess", lib, sys.ADR(ExitProcess));
  GetProc("ExitThread", lib, sys.ADR(ExitThread));
  GetProc("GetCurrentThreadId", lib, sys.ADR(GetCurrentThreadId));
  GetProc("GlobalAlloc", lib, sys.ADR(Alloc));
  GetProc("GlobalFree", lib, sys.ADR(Free));

  lib := LoadLibraryA(sys.ADR("msvcrt.dll"));
  GetProc("strncmp", lib, sys.ADR(strncmp));

  lib := LoadLibraryA(sys.ADR("user32.dll"));
  GetProc("MessageBoxA", lib, sys.ADR(MessageBoxA));
END init;

END API.