/*

 * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include <Windows.h>

#include <io.h>

#include <stdio.h>

#include <string.h>

#include <malloc.h>

/*

 * Test if pos points to /cygdrive/_/ where _ can

 * be any character.

 */

int is_cygdrive_here(int pos, char *in, int len)

{

  // Length of /cygdrive/c/ is 12

  if (pos+12 > len) return 0;

  if (in[pos+11]=='/' &&

      in[pos+9]=='/' &&

      in[pos+8]=='e' &&

      in[pos+7]=='v' &&

      in[pos+6]=='i' &&

      in[pos+5]=='r' &&

      in[pos+4]=='d' &&

      in[pos+3]=='g' &&

      in[pos+2]=='y' &&

      in[pos+1]=='c' &&

      in[pos+0]=='/') {

    return 1;

  }

  return 0;

}

/*

 * Replace /cygdrive/_/ with _:/

 * Works in place since drive letter is always

 * shorter than /cygdrive/

 */

char *replace_cygdrive(char *in)

{

  int len = strlen(in);

  char *out = malloc(len+1);

  int i,j;

  if (len < 12) {

    strcpy(out, in);

    return out;

  }

  for (i = 0, j = 0; i<len;) {

    if (is_cygdrive_here(i, in, len)) {

      out[j++] = in[i+10];

      out[j++] = ':';

      i+=11;

    } else {

      out[j] = in[i];

      i++;

      j++;

    }

  }

  out[j] = 0;

  return out;

}

void append(char **b, size_t *bl, size_t *u, char *add, size_t addlen)

{

  while ( (addlen+*u+1) > *bl) {

    *bl *= 2;

    *b = realloc(*b, *bl);

  }

  memcpy(*b+*u, add, addlen);

  *u += addlen;

}

/*

 * Creates a new string from in where the first occurance of sub is

 * replaced by rep.

 */

char *replace_substring(char *in, char *sub, char *rep)

{

  int in_len = strlen(in);

  int sub_len = strlen(sub);

  int rep_len = strlen(rep);

  char *out = malloc(in_len - sub_len + rep_len + 1);

  char *p;

  if (!(p = strstr(in, sub))) {

    // If sub isn't a substring of in, just return in.

    return in;

  }

  // Copy characters from beginning of in to start of sub.

  strncpy(out, in, p - in);

  out[p - in] = '\0';

  sprintf(out + (p - in), "%s%s", rep, p + sub_len);

  return out;

}

char *files_to_delete[1024];

int num_files_to_delete = 0;

char *fix_at_file(char *in)

{

  char *tmpdir;

  char name[2048];

  char *atname;

  char *buffer;

  size_t buflen=65536;

  size_t used=0;

  size_t len;

  int rc;

  FILE *atout;

  FILE *atin;

  char block[2048];

  size_t blocklen;

  char *fixed;

  atin = fopen(in+1, "r");

  if (atin == NULL) {

    fprintf(stderr, "Could not read at file %s\n", in+1);

    exit(-1);

  }

  tmpdir = getenv("TMP");

  if (tmpdir == NULL) {

    tmpdir = "c:/cygwin/tmp";

  }

  _snprintf(name, sizeof(name), "%s\\atfile_XXXXXX", tmpdir);

  rc = _mktemp_s(name, strlen(name)+1);

  if (rc) {

    fprintf(stderr, "Could not create temporary file name for at file!\n");

    exit(-1);

  }

  atout = fopen(name, "w");

  if (atout == NULL) {

    fprintf(stderr, "Could open temporary file for writing! %s\n", name);

    exit(-1);

  }

  buffer = malloc(buflen);

  while((blocklen = fread(block,1,sizeof(block),atin)) > 0) {

    append(&buffer, &buflen, &used, block, blocklen);

  }

  buffer[used] = 0;

  fixed = replace_cygdrive(buffer);

  fwrite(fixed, strlen(fixed), 1, atout);

  fclose(atin);

  fclose(atout);

  free(fixed);

  free(buffer);

  files_to_delete[num_files_to_delete] = malloc(strlen(name)+1);

  strcpy(files_to_delete[num_files_to_delete], name);

  num_files_to_delete++;

  atname = malloc(strlen(name)+2);

  atname[0] = '@';

  strcpy(atname+1, name);

  return atname;

}

int main(int argc, char **argv)

{

    STARTUPINFO si;

    PROCESS_INFORMATION pi;

    unsigned short rc;

    char *new_at_file;

    char *old_at_file;

    char *line;

    int i;

    DWORD exitCode;

    if (argc<2) {

        fprintf(stderr, "Usage: uncygdrive.exe /cygdrive/c/WINDOWS/notepad.exe /cygdrive/c/x/test.txt");

        exit(0);

    }

    line = replace_cygdrive(strstr(GetCommandLine(), argv[1]));

    for (i=1; i<argc; ++i) {

       if (argv[i][0] == '@') {

          // Found at-file! Fix it!

          old_at_file = replace_cygdrive(argv[i]);

          new_at_file = fix_at_file(old_at_file);

          line = replace_substring(line, old_at_file, new_at_file);

       }

    }

    if (getenv("DEBUG_UNCYGDRIVE") != NULL) {

      fprintf(stderr, "uncygdrive >%s<\n", line);

    }

    ZeroMemory(&si,sizeof(si));

    si.cb=sizeof(si);

    ZeroMemory(&pi,sizeof(pi));

    rc = CreateProcess(NULL,

                       line,

                       0,

                       0,

                       TRUE,

                       0,

                       0,

                       0,

                       &si,

                       &pi);

    if(!rc)

    {

      //Could not start process;

      fprintf(stderr, "Could not start process!\n");

      exit(-1);

    }

    WaitForSingleObject(pi.hProcess,INFINITE);

    GetExitCodeProcess(pi.hProcess,&exitCode);

    if (getenv("DEBUG_UNCYGDRIVE") != NULL) {

      for (i=0; i<num_files_to_delete; ++i) {

        fprintf(stderr, "Not deleting temporary uncygdrive file %s\n",

                files_to_delete[i]);

      }

    }

    else {

      for (i=0; i<num_files_to_delete; ++i) {

        remove(files_to_delete[i]);

      }

    }

    exit(exitCode);

}