/* Copyright (c) 2008, Avian Contributors

   Permission to use, copy, modify, and/or distribute this software
   for any purpose with or without fee is hereby granted, provided
   that the above copyright notice and this permission notice appear
   in all copies.

   There is NO WARRANTY for this software.  See license.txt for
   details. */

#include "math.h"
#include "stdlib.h"
#include "sys/time.h"
#include "time.h"
#include "time.h"
#include "string.h"
#include "stdio.h"
#include "stdint.h"
#include "jni.h"
#include "jni-util.h"
#include "errno.h"
#include "fcntl.h"
#include "unistd.h"

#ifdef WIN32
#  include "windows.h"
#  include "winbase.h"
#  include "io.h"
#  include "tchar.h"
#  define SO_PREFIX ""
#else
#  define SO_PREFIX "lib"
#include "sys/wait.h"
#endif

#ifdef __APPLE__
#  define SO_SUFFIX ".jnilib"
#elif defined WIN32
#  define SO_SUFFIX ".dll"
#else
#  define SO_SUFFIX ".so"
#endif

namespace {
#ifdef WIN32
  char* getErrorStr(DWORD err){
    // The poor man's error string, just print the error code 
    char * errStr = (char*) malloc(9 * sizeof(char));
    snprintf(errStr, 9, "%d", (int) err);
    return errStr;
    
    // The better way to do this, if I could figure out how to convert LPTSTR to char*
    //char* errStr;
    //LPTSTR s;
    //if(FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
    //                 FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err, 0, &s, 0, NULL) == 0)
    //{
    //  errStr.Format("Unknown error occurred (%08x)", err);
    //} else {
    //  errStr = s;
    //}
    //return errStr;
  }

  void makePipe(JNIEnv* e, HANDLE p[2])
  {
    SECURITY_ATTRIBUTES sa;
    sa.nLength = sizeof(sa);
    sa.bInheritHandle = 1;
    sa.lpSecurityDescriptor = 0;
  
    BOOL success = CreatePipe(p, p + 1, &sa, 0);
    if (not success) {
      throwNew(e, "java/io/IOException", getErrorStr(GetLastError()));
    }
  }
  
  int descriptor(JNIEnv* e, HANDLE h)
  {
    int fd = _open_osfhandle(reinterpret_cast<long>(h), 0);
    if (fd == -1) {
      throwNew(e, "java/io/IOException", strerror(errno));
    }
    return fd;
  }
#else
  void makePipe(JNIEnv* e, int p[2])
  {
    if(pipe(p) != 0) {
      throwNew(e, "java/io/IOException", strerror(errno));
    }
  }
  
  void safeClose(int &fd)
  {
    if(fd != -1) close(fd);
    fd = -1;
  }
  
  void close(int p[2])
  {
    ::close(p[0]);
    ::close(p[1]);
  }
  
  void clean(JNIEnv* e, jobjectArray command, char** p)
  {
    int i = 0;
    for(char** x = p; *x; ++x, ++i){
      jstring element = (jstring) e->GetObjectArrayElement(command, i);
      e->ReleaseStringUTFChars(element, *x);
    }
    free(p);
  }
#endif  
}

#ifdef WIN32
extern "C" JNIEXPORT void JNICALL 
Java_java_lang_Runtime_exec(JNIEnv* e, jclass, 
                            jobjectArray command, jlongArray process)
{
  
  int size = 0;
  for (int i = 0; i < e->GetArrayLength(command); ++i){
    jstring element = (jstring) e->GetObjectArrayElement(command, i);
    size += e->GetStringUTFLength(element) + 1;
  } 
   
  char line[size];
  char* linep = line;
  for (int i = 0; i < e->GetArrayLength(command); ++i) {
    if (i) *(linep++) = _T(' ');
    jstring element = (jstring) e->GetObjectArrayElement(command, i);
    const char* s =  e->GetStringUTFChars(element, 0);
    _tcscpy(linep, s);
    e->ReleaseStringUTFChars(element, s);
    linep += e->GetStringUTFLength(element);
  }
  *(linep++) = _T('\0');
 
  HANDLE in[] = { 0, 0 };
  HANDLE out[] = { 0, 0 };
  HANDLE err[] = { 0, 0 };
  
  makePipe(e, in);
  SetHandleInformation(in[0], HANDLE_FLAG_INHERIT, 0);
  jlong inDescriptor = static_cast<jlong>(descriptor(e, in[0]));
  if(e->ExceptionOccurred()) return;
  e->SetLongArrayRegion(process, 1, 1, &inDescriptor);
  makePipe(e, out);
  SetHandleInformation(out[1], HANDLE_FLAG_INHERIT, 0);
  jlong outDescriptor = static_cast<jlong>(descriptor(e, out[1]));
  if(e->ExceptionOccurred()) return;
  e->SetLongArrayRegion(process, 2, 1, &outDescriptor);
  makePipe(e, err);
  SetHandleInformation(err[0], HANDLE_FLAG_INHERIT, 0);
  jlong errDescriptor = static_cast<jlong>(descriptor(e, err[0]));
  if(e->ExceptionOccurred()) return;
  e->SetLongArrayRegion(process, 3, 1, &errDescriptor);
  
  PROCESS_INFORMATION pi;
  ZeroMemory(&pi, sizeof(pi));
 
  STARTUPINFO si;
  ZeroMemory(&si, sizeof(si));
  si.cb = sizeof(si);
  si.dwFlags = STARTF_USESTDHANDLES;
  si.hStdOutput = in[1];
  si.hStdInput = out[0];
  si.hStdError = err[1];
 
  BOOL success = CreateProcess(0, (LPSTR) line, 0, 0, 1,
                               CREATE_NO_WINDOW | CREATE_UNICODE_ENVIRONMENT,
                               0, 0, &si, &pi);
  
  if (not success) {
    throwNew(e, "java/io/IOException", getErrorStr(GetLastError()));
    return;
  }
  
  jlong pid = reinterpret_cast<jlong>(pi.hProcess);
  e->SetLongArrayRegion(process, 0, 1, &pid);
  
}

extern "C" JNIEXPORT jint JNICALL 
Java_java_lang_Runtime_exitValue(JNIEnv* e, jclass, jlong pid)
{
  DWORD exitCode;
  BOOL success = GetExitCodeProcess(reinterpret_cast<HANDLE>(pid), &exitCode);
  if(not success){
    throwNew(e, "java/lang/Exception", getErrorStr(GetLastError()));
  } else if(exitCode == STILL_ACTIVE){
    throwNew(e, "java/lang/IllegalThreadStateException", "Process is still active");
  }
  return exitCode;
}

extern "C" JNIEXPORT jint JNICALL 
Java_java_lang_Runtime_waitFor(JNIEnv* e, jclass, jlong pid)
{
  DWORD exitCode;
  WaitForSingleObject(reinterpret_cast<HANDLE>(pid), INFINITE);
  BOOL success = GetExitCodeProcess(reinterpret_cast<HANDLE>(pid), &exitCode);
  if(not success){
    throwNew(e, "java/lang/Exception", getErrorStr(GetLastError()));
  }
  return exitCode;
}
#else
extern "C" JNIEXPORT void JNICALL 
Java_java_lang_Runtime_exec(JNIEnv* e, jclass, 
                            jobjectArray command, jlongArray process)
{
  char** argv = static_cast<char**>(malloc((e->GetArrayLength(command) + 1) * sizeof(char*)));
  int i;
  for(i = 0; i < e->GetArrayLength(command); i++){
    jstring element = (jstring) e->GetObjectArrayElement(command, i);
    char* s = const_cast<char*>(e->GetStringUTFChars(element, 0));
    argv[i] = s;
  }
  argv[i] = 0;
  
  int in[] = { -1, -1 };
  int out[] = { -1, -1 };
  int err[] = { -1, -1 };
  int msg[] = { -1, -1 };
  
  makePipe(e, in);
  if(e->ExceptionOccurred()) return;
  jlong inDescriptor = static_cast<jlong>(in[0]);
  e->SetLongArrayRegion(process, 1, 1, &inDescriptor);
  makePipe(e, out);
  if(e->ExceptionOccurred()) return;
  jlong outDescriptor = static_cast<jlong>(out[1]);
  e->SetLongArrayRegion(process, 1, 1, &outDescriptor);
  makePipe(e, err);
  if(e->ExceptionOccurred()) return;
  jlong errDescriptor = static_cast<jlong>(err[0]);
  e->SetLongArrayRegion(process, 1, 1, &errDescriptor);
  makePipe(e, msg);
  if(e->ExceptionOccurred()) return;
  if(fcntl(msg[1], F_SETFD, FD_CLOEXEC) != 0) {
    throwNew(e, "java/io/IOException", strerror(errno));
    return;
  }
  
  pid_t pid = fork();
  switch(pid){
  case -1: // error
    throwNew(e, "java/io/IOException", strerror(errno));
    return;
  case 0: { // child
    // Setup stdin, stdout and stderr
    dup2(in[1], 1);
    close(in);
    dup2(out[0], 0);
    close(out);
    dup2(err[1], 2);
    close(err);
    close(msg[0]);
    
    execvp(argv[0], argv);
    
    // Error if here
    char c = errno;
    write(msg[1], &c, 1);
    exit(127);
  } break;
    
  default: { //parent
    jlong JNIPid = static_cast<jlong>(pid);
    e->SetLongArrayRegion(process, 0, 1, &JNIPid);
    
    safeClose(in[1]);
    safeClose(out[0]);
    safeClose(err[1]);
    safeClose(msg[1]);
      
    char c;
    int r = read(msg[0], &c, 1);
    if(r == -1) {
      throwNew(e, "java/io/IOException", strerror(errno));
      return;
    } else if(r) {
      throwNew(e, "java/io/IOException", strerror(c));
      return;
    }
  } break;
  }
  
  safeClose(msg[0]);
  clean(e, command, argv);
  
  fcntl(in[0], F_SETFD, FD_CLOEXEC);
  fcntl(out[1], F_SETFD, FD_CLOEXEC);
  fcntl(err[0], F_SETFD, FD_CLOEXEC);
}

extern "C" JNIEXPORT jint JNICALL 
Java_java_lang_Runtime_exitValue(JNIEnv* e, jclass, jlong pid)
{
  int status;
  pid_t returned = waitpid(pid, &status, WNOHANG);
  if(returned == 0){
    throwNew(e, "java/lang/IllegalThreadStateException", strerror(errno));
  } else if(returned == -1){
    throwNew(e, "java/lang/Exception", strerror(errno));
  } 
  
  return WEXITSTATUS(status);
}

extern "C" JNIEXPORT jint JNICALL 
Java_java_lang_Runtime_waitFor(JNIEnv*, jclass, jlong pid)
{
  bool finished = false;
  int status;
  int exitCode;
  while(!finished){
    waitpid(pid, &status, 0);
    if(WIFEXITED(status)){
      finished = true;
      exitCode = WEXITSTATUS(status);
    } else if(WIFSIGNALED(status)){
      finished = true;
      exitCode = -1;
    }
  }
  
  return exitCode;
}
#endif

extern "C" JNIEXPORT jstring JNICALL
Java_java_lang_System_getProperty(JNIEnv* e, jclass, jstring name,
                                  jbooleanArray found)
{
  jstring r = 0;
  const char* chars = e->GetStringUTFChars(name, 0);
  if (chars) {
#ifdef WIN32 
    if (strcmp(chars, "line.separator") == 0) {
      r = e->NewStringUTF("\r\n");
    } else if (strcmp(chars, "file.separator") == 0) {
      r = e->NewStringUTF("\\");
    } else if (strcmp(chars, "os.name") == 0) {
      r = e->NewStringUTF("Windows");
    } else if (strcmp(chars, "java.io.tmpdir") == 0) {
      TCHAR buffer[MAX_PATH];
      GetTempPath(MAX_PATH, buffer);
      r = e->NewStringUTF(buffer);
    } else if (strcmp(chars, "user.home") == 0) {
      LPWSTR home = _wgetenv(L"USERPROFILE");
      r = e->NewString(reinterpret_cast<jchar*>(home), lstrlenW(home));
    }
#else
    if (strcmp(chars, "line.separator") == 0) {
      r = e->NewStringUTF("\n");
    } else if (strcmp(chars, "file.separator") == 0) {
      r = e->NewStringUTF("/");
    } else if (strcmp(chars, "os.name") == 0) {
#ifdef __APPLE__
      r = e->NewStringUTF("Mac OS X");
#else
      r = e->NewStringUTF("Linux");
#endif
    } else if (strcmp(chars, "java.io.tmpdir") == 0) {
      r = e->NewStringUTF("/tmp");
    } else if (strcmp(chars, "user.home") == 0) {
      r = e->NewStringUTF(getenv("HOME"));      
    }
#endif

    e->ReleaseStringUTFChars(name, chars);
  }

  if (r) {
    jboolean v = true;
    e->SetBooleanArrayRegion(found, 0, 1, &v);
  }

  return r;
}

extern "C" JNIEXPORT jlong JNICALL
Java_java_lang_System_currentTimeMillis(JNIEnv*, jclass)
{
#ifdef WIN32
  static LARGE_INTEGER frequency;
  static LARGE_INTEGER time;
  static bool init = true;

  if (init) {
    QueryPerformanceFrequency(&frequency);

    if (frequency.QuadPart == 0) {
      return 0;      
    }

    init = false;
  }

  QueryPerformanceCounter(&time);
  return static_cast<int64_t>
    (((static_cast<double>(time.QuadPart)) * 1000.0) /
     (static_cast<double>(frequency.QuadPart)));
#else
  timeval tv = { 0, 0 };
  gettimeofday(&tv, 0);
  return (static_cast<jlong>(tv.tv_sec) * 1000) +
    (static_cast<jlong>(tv.tv_usec) / 1000);
#endif
}

extern "C" JNIEXPORT jstring JNICALL
Java_java_lang_System_doMapLibraryName(JNIEnv* e, jclass, jstring name)
{
  jstring r = 0;
  const char* chars = e->GetStringUTFChars(name, 0);
  if (chars) {
    unsigned nameLength = strlen(chars);
    unsigned size = sizeof(SO_PREFIX) + nameLength + sizeof(SO_SUFFIX);
    char buffer[size];
    snprintf(buffer, size, SO_PREFIX "%s" SO_SUFFIX, chars);
    r = e->NewStringUTF(buffer);

    e->ReleaseStringUTFChars(name, chars);
  }
  return r;
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_sin(JNIEnv*, jclass, jdouble val)
{
  return sin(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_cos(JNIEnv*, jclass, jdouble val)
{
  return cos(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_sqrt(JNIEnv*, jclass, jdouble val)
{
  return sqrt(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_pow(JNIEnv*, jclass, jdouble val, jdouble exp)
{
  return pow(val, exp);
}

extern "C" JNIEXPORT void JNICALL
Java_java_lang_Math_natRandomInitialize(JNIEnv*, jclass, jlong val)
{
#ifdef WIN32
  srand(val);
#else
  srand48(val);
#endif
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_natRandom(JNIEnv*, jclass)
{
#ifdef WIN32
  return rand();
#else
  return drand48();
#endif
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_floor(JNIEnv*, jclass, jdouble val)
{
  return floor(val);
}

extern "C" JNIEXPORT jdouble JNICALL
Java_java_lang_Math_ceil(JNIEnv*, jclass, jdouble val)
{
  return ceil(val);
}

extern "C" JNIEXPORT jint JNICALL
Java_java_lang_Double_fillBufferWithDouble(JNIEnv* e, jclass, jdouble val,
					   jbyteArray buffer, jint bufferSize) {
  jboolean isCopy;
  jbyte* buf = e->GetByteArrayElements(buffer, &isCopy);
  jint count = snprintf(reinterpret_cast<char*>(buf), bufferSize, "%g", val);
  e->ReleaseByteArrayElements(buffer, buf, 0);
  return count;
}