/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim:expandtab:shiftwidth=2:tabstop=8:

 */

/* vim:set ts=8 sw=2 et cindent: */

/* 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 <stdlib.h>

#include <string.h>

#include <strings.h>

#include <unistd.h>

#include <limits.h>

#include "RemoteUtils.h"

#ifdef IS_BIG_ENDIAN

#define TO_LITTLE_ENDIAN32(x) \

    ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \

    (((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))

#else

#define TO_LITTLE_ENDIAN32(x) (x)

#endif

#ifndef MAX_PATH

#ifdef PATH_MAX

#define MAX_PATH PATH_MAX

#else

#define MAX_PATH 1024

#endif

#endif

/* like strcpy, but return the char after the final null */

static char*

estrcpy(const char* s, char* d)

{

  while (*s)

    *d++ = *s++;

  *d++ = '\0';

  return d;

}

/* Construct a command line from given args and desktop startup ID.

 * Returned buffer must be released by free().

 */

char*

ConstructCommandLine(int32_t argc, char **argv,

                     const char* aDesktopStartupID,

                     int *aCommandLineLength)

{

  char cwdbuf[MAX_PATH];

  if (!getcwd(cwdbuf, MAX_PATH))

    return nullptr;

  // the commandline property is constructed as an array of int32_t

  // followed by a series of null-terminated strings:

  //

  // [argc][offsetargv0][offsetargv1...]<workingdir>\0<argv[0]>\0argv[1]...\0

  // (offset is from the beginning of the buffer)

  static char desktopStartupPrefix[] = " DESKTOP_STARTUP_ID=";

  int32_t argvlen = strlen(cwdbuf);

  for (int i = 0; i < argc; ++i) {

    int32_t len = strlen(argv[i]);

    if (i == 0 && aDesktopStartupID) {

      len += sizeof(desktopStartupPrefix) - 1 + strlen(aDesktopStartupID);

    }

    argvlen += len;

  }

  auto* buffer = (int32_t*) malloc(argvlen + argc + 1 +

                                   sizeof(int32_t) * (argc + 1));

  if (!buffer)

    return nullptr;

  buffer[0] = TO_LITTLE_ENDIAN32(argc);

  auto *bufend = (char*) (buffer + argc + 1);

  bufend = estrcpy(cwdbuf, bufend);

  for (int i = 0; i < argc; ++i) {

    buffer[i + 1] = TO_LITTLE_ENDIAN32(bufend - ((char*) buffer));

    bufend = estrcpy(argv[i], bufend);

    if (i == 0 && aDesktopStartupID) {

      bufend = estrcpy(desktopStartupPrefix, bufend - 1);

      bufend = estrcpy(aDesktopStartupID, bufend - 1);

    }

  }

#ifdef DEBUG_command_line

  int32_t   debug_argc   = TO_LITTLE_ENDIAN32(*buffer);

  char *debug_workingdir = (char*) (buffer + argc + 1);

  printf("Sending command line:\n"

         "  working dir: %s\n"

         "  argc:\t%i",

         debug_workingdir,

         debug_argc);

  int32_t  *debug_offset = buffer + 1;

  for (int debug_i = 0; debug_i < debug_argc; ++debug_i)

    printf("  argv[%i]:\t%s\n", debug_i,

           ((char*) buffer) + TO_LITTLE_ENDIAN32(debug_offset[debug_i]));

#endif

  *aCommandLineLength = bufend - reinterpret_cast<char *>(buffer);

  return reinterpret_cast<char *>(buffer);

}