/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* ex: set tabstop=8 softtabstop=4 shiftwidth=4 expandtab: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsDebug.h"
#include "nsString.h"
#include "nsCUPSShim.h"
#include "mozilla/ArrayUtils.h"
#include "prlink.h"

// List of symbols to find in libcups. Must match symAddr[] defined in Init().
// Making this an array of arrays instead of pointers allows storing the
// whole thing in read-only memory.
static const char gSymName[][sizeof("cupsPrintFile")] = {
    {"cupsAddOption"}, {"cupsFreeDests"}, {"cupsGetDest"},
    {"cupsGetDests"},  {"cupsPrintFile"}, {"cupsTempFd"},
};
static const int gSymNameCt = mozilla::ArrayLength(gSymName);

bool nsCUPSShim::Init() {
  mCupsLib = PR_LoadLibrary("libcups.so.2");
  if (!mCupsLib) return false;

  // List of symbol pointers. Must match gSymName[] defined above.
  void **symAddr[] = {
      (void **)&mCupsAddOption, (void **)&mCupsFreeDests,
      (void **)&mCupsGetDest,   (void **)&mCupsGetDests,
      (void **)&mCupsPrintFile, (void **)&mCupsTempFd,
  };

  for (int i = gSymNameCt; i--;) {
    *(symAddr[i]) = PR_FindSymbol(mCupsLib, gSymName[i]);
    if (!*(symAddr[i])) {
#ifdef DEBUG
      nsAutoCString msg(gSymName[i]);
      msg.AppendLiteral(" not found in CUPS library");
      NS_WARNING(msg.get());
#endif
      PR_UnloadLibrary(mCupsLib);
      mCupsLib = nullptr;
      return false;
    }
  }
  return true;
}