/*

 * Copyright (c) 2011, 2014, 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>

void report_error(char const * msg)

{

  LPVOID lpMsgBuf;

  DWORD dw = GetLastError();

  FormatMessage(

      FORMAT_MESSAGE_ALLOCATE_BUFFER |

      FORMAT_MESSAGE_FROM_SYSTEM |

      FORMAT_MESSAGE_IGNORE_INSERTS,

      NULL,

      dw,

      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),

      (LPTSTR) &lpMsgBuf,

      0,

      NULL);

  fprintf(stderr,

          "%s  Failed with error %d: %s\n",

          msg, dw, lpMsgBuf);

  LocalFree(lpMsgBuf);

}

/*

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

 * be any character.

 */

int is_cygdrive_here(int pos, char const *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_cygwin(char const *in)

{

  size_t len = strlen(in);

  char *out = (char*) malloc(len+1);

  int i,j;

  if (len < 12) {

    memmove(out, in, len + 1);

    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 = (char*) 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 = (char *) 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* msys_path_list; // @-separated list of paths prefix to look for

char* msys_path_list_end; // Points to last \0 in msys_path_list.

void setup_msys_path_list(char const * argument)

{

  char* p;

  char* drive_letter_pos;

  msys_path_list = strdup(&argument[2]);

  msys_path_list_end = &msys_path_list[strlen(msys_path_list)];

  // Convert all at-sign (@) in path list to \0.

  // @ was chosen as separator to minimize risk of other tools messing around with it

  p = msys_path_list;

  do {

    if (p[1] == ':') {

      // msys has mangled our path list, restore it from c:/... to /c/...

      drive_letter_pos = p+1;

      *drive_letter_pos = *p;

      *p = '/';

    }

    // Look for an @ in the list

    p = strchr(p, '@');

    if (p != NULL) {

      *p = '\0';

      p++;

    }

  } while (p != NULL);

}

char *replace_cygdrive_msys(char const *in)

{

  char* str;

  char* prefix;

  char* p;

  str = strdup(in);

  // For each prefix in the path list, search for it and replace /c/... with c:/...

  for (prefix = msys_path_list; prefix < msys_path_list_end && prefix != NULL; prefix += strlen(prefix)+1) {

    p=str;

    while ((p = strstr(p, prefix))) {

      char* drive_letter = p+1;

      *p = *drive_letter;

      *drive_letter = ':';

      p++;

    }

  }

  return str;

}

char*(*replace_cygdrive)(char const *in) = NULL;

char *files_to_delete[1024];

int num_files_to_delete = 0;

char *fix_at_file(char const *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("TEMP");

  if (tmpdir == NULL) {

#if _WIN64

    tmpdir = "c:/cygwin64/tmp";

#else

    tmpdir = "c:/cygwin/tmp";

#endif

  }

  _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 not open temporary file for writing! %s\n", name);

    exit(-1);

  }

  buffer = (char*) malloc(buflen);

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

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

  }

  buffer[used] = 0;

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

    fprintf(stderr, "fixpath input from @-file %s: %s\n", &in[1], buffer);

  }

  fixed = replace_cygdrive(buffer);

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

    fprintf(stderr, "fixpath converted to @-file %s is: %s\n", name, fixed);

  }

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

  fclose(atin);

  fclose(atout);

  free(fixed);

  free(buffer);

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

  strcpy(files_to_delete[num_files_to_delete], name);

  num_files_to_delete++;

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

  atname[0] = '@';

  strcpy(atname+1, name);

  return atname;

}

// given an argument, convert it to the windows command line safe quoted version

// using rules from:

// http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx

// caller is responsible for freeing both input and output.

char * quote_arg(char const * in_arg) {

  char *quoted = NULL;

  char *current = quoted;

  int pass;

  if(strpbrk(in_arg, " \t\n\v\r\\\"") == NULL) {

     return _strdup(in_arg);

  }

  // process the arg twice. Once to calculate the size and then to copy it.

  for(pass=1; pass<=2; pass++) {

    char const *arg = in_arg;

    // initial "

    if(pass == 2) {

      *current = '\"';

    }

    current++;

    // process string to be quoted until NUL

    do {

      int escapes = 0;

      while (*arg == '\\') {

        // count escapes.

        escapes++;

        arg++;

      }

      if (*arg == '\0') {

         // escape the escapes before final "

         escapes *= 2;

      } else if (*arg == '"') {

        // escape the escapes and the "

        escapes = escapes * 2 + 1;

      } else {

         // escapes aren't special, just echo them.

      }

      // emit some escapes

      while (escapes > 0) {

        if (pass == 2) {

          *current = '\\';

        }

        current++;

        escapes--;

      }

      // and the current char

      if (pass == 2) {

        *current = *arg;

      }

      current++;

    } while( *arg++ != '\0');

    // allocate the buffer

    if (pass == 1) {

      size_t alloc = (size_t) (current - quoted + (ptrdiff_t) 2);

      current = quoted = (char*) calloc(alloc, sizeof(char));

    }

  }

  // final " and \0

  *(current - 1) = '"';

  *current = '\0';

  return quoted;

}

int main(int argc, char const ** argv)

{

    STARTUPINFO si;

    PROCESS_INFORMATION pi;

    unsigned short rc;

    char *line;

    char *current;

    int i, cmd;

    DWORD exitCode;

    if (argc<2 || argv[1][0] != '-' || (argv[1][1] != 'c' && argv[1][1] != 'm')) {

        fprintf(stderr, "Usage: fixpath -c|m<path@path@...> /cygdrive/c/WINDOWS/notepad.exe [/cygdrive/c/x/test.txt|@/cygdrive/c/x/atfile]\n");

        exit(0);

    }

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

      char const * cmdline = GetCommandLine();

      fprintf(stderr, "fixpath input line >%s<\n", strstr( cmdline , argv[1]));

    }

    if (argv[1][1] == 'c' && argv[1][2] == '\0') {

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

        fprintf(stderr, "fixpath using cygwin mode\n");

      }

      replace_cygdrive = replace_cygdrive_cygwin;

    } else if (argv[1][1] == 'm') {

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

        fprintf(stderr, "fixpath using msys mode, with path list: %s\n", &argv[1][2]);

      }

      setup_msys_path_list(argv[1]);

      replace_cygdrive = replace_cygdrive_msys;

    } else {

      fprintf(stderr, "fixpath Unknown mode: %s\n", argv[1]);

      exit(-1);

    }

    i = 2;

    // handle assignments

    while (i < argc) {

      char const * assignment = strchr(argv[i], '=');

      if (assignment != NULL && assignment != argv[i]) {

        size_t var_len = (size_t) (assignment - argv[i] + (ptrdiff_t) 1);

        char *var = (char *) calloc(var_len, sizeof(char));

        char *val = replace_cygdrive(assignment + 1);

        memmove(var, argv[i], var_len);

        var[var_len - 1] = '\0';

        strupr(var);

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

          fprintf(stderr, "fixpath setting var >%s< to >%s<\n", var, val);

        }

        rc = SetEnvironmentVariable(var, val);

        if(!rc) {

          // Could not set var for some reason.  Try to report why.

          const int msg_len = 80 + var_len + strlen(val);

          char * msg = (char *) alloca(msg_len);

          _snprintf_s(msg, msg_len, _TRUNCATE, "Could not set environment variable [%s=%s]", var, val);

          report_error(msg);

          exit(1);

        }

        free(var);

        free(val);

      } else {

        // no more assignments;

        break;

      }

      i++;

    }

    // remember index of the command

    cmd = i;

    // handle command and it's args.

    while (i < argc) {

      char const *replaced = replace_cygdrive(argv[i]);

      if(replaced[0] == '@') {

        // Found at-file! Fix it!

        replaced = fix_at_file(replaced);

      }

      argv[i] = quote_arg(replaced);

      i++;

    }

    // determine the length of the line

    line = NULL;

    // args

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

      line += (ptrdiff_t) strlen(argv[i]);

    }

    // spaces and null

    line += (ptrdiff_t) (argc - cmd + 1);

    // allocate

    line = (char*) calloc(line - (char*) NULL, sizeof(char));

    // copy in args.

    current = line;

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

      ptrdiff_t len = strlen(argv[i]);

      if (i != cmd) {

        *current++ = ' ';

      }

      memmove(current, argv[i], len);

      current += len;

    }

    *current = '\0';

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

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

    }

    if(cmd == argc) {

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

         fprintf(stderr, "fixpath no command provided!\n");

       }

       exit(0);

    }

    ZeroMemory(&si,sizeof(si));

    si.cb=sizeof(si);

    ZeroMemory(&pi,sizeof(pi));

    fflush(stderr);

    fflush(stdout);

    rc = CreateProcess(NULL,

                       line,

                       0,

                       0,

                       TRUE,

                       0,

                       NULL,

                       NULL,

                       &si,

                       &pi);

    if(!rc) {

      // Could not start process for some reason.  Try to report why:

      report_error("Could not start process!");

      exit(126);

    }

    WaitForSingleObject(pi.hProcess,INFINITE);

    GetExitCodeProcess(pi.hProcess,&exitCode);

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

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

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

                files_to_delete[i]);

      }

    } else {

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

        remove(files_to_delete[i]);

      }

    }

    if (exitCode != 0) {

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

        fprintf(stderr, "fixpath exit code %d\n",

                exitCode);

      }

    }