/**
 * @copyright
 * ====================================================================
 * Copyright (c) 2003 CollabNet.  All rights reserved.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution.  The terms
 * are also available at http://subversion.tigris.org/license-1.html.
 * If newer versions of this license are posted there, you may use a
 * newer version instead, at your option.
 *
 * This software consists of voluntary contributions made by many
 * individuals.  For exact contribution history, see the revision
 * history and logs, available at http://subversion.tigris.org/.
 * ====================================================================
 * @endcopyright
 *
 * @file JNIUtil.cpp
 * @brief Implementation of the class JNIUtil
 */

#include "JNIUtil.h"
#include <sstream>
#include <locale.h>
#include <apr_strings.h>
#include <apr_tables.h>
#include <apr_general.h>
#include <apr_lib.h>

#include "svn_pools.h"
#include "svn_wc.h"
#include "svn_path.h"
#include <apr_file_info.h>
#include "svn_private_config.h"
#ifdef WIN32
/* FIXME: We're using an internal APR header here, which means we
   have to build Subversion with APR sources. This being Win32-only,
   that should be fine for now, but a better solution must be found in
   combination with issue #850. */
extern "C" {
#include <arch/win32/apr_arch_utf8.h>
};
#endif

#include "SVNBase.h"
#include "JNIMutex.h"
#include "JNICriticalSection.h"
#include "JNIThreadData.h"
#include "JNIStringHolder.h"
#include "Pool.h"

// Static members of JNIUtil are allocated here.
apr_pool_t *JNIUtil::g_pool = NULL;
std::list<SVNBase*> JNIUtil::g_finalizedObjects;
JNIMutex *JNIUtil::g_finalizedObjectsMutex = NULL;
JNIMutex *JNIUtil::g_logMutex = NULL;
JNIMutex *JNIUtil::g_globalPoolMutext = NULL;
bool JNIUtil::g_initException;
bool JNIUtil::g_inInit;
JNIEnv *JNIUtil::g_initEnv;
char JNIUtil::g_initFormatBuffer[formatBufferSize];
int JNIUtil::g_logLevel = JNIUtil::noLog;
std::ofstream JNIUtil::g_logStream;

/**
 * Initialize the environment for all requests.
 * @param env   the JNI environment for this request
 */
bool JNIUtil::JNIInit(JNIEnv *env)
{
  // Clear all standing exceptions.
  env->ExceptionClear();

  // Remember the env paramater for the remainder of the request.
  setEnv(env);

  // Lock the list of finalized objects.
  JNICriticalSection cs(*g_finalizedObjectsMutex) ;
  if (isExceptionThrown())
    return false;

  // Delete all finalized, but not yet deleted objects.
  for (std::list<SVNBase*>::iterator it = g_finalizedObjects.begin();
       it != g_finalizedObjects.end();
       ++it)
    {
      delete *it;
    }
  g_finalizedObjects.clear();

  return true;
}

/**
 * Initialize the environment for all requests.
 * @param env   the JNI environment for this request
 */
bool JNIUtil::JNIGlobalInit(JNIEnv *env)
{
  // This method has to be run only once during the run a program.
  static bool run = false;
  if (run) // already run
    return true;

  run = true;

  // Do not run this part more than one time.  This leaves a small
  // time window when two threads create their first SVNClient and
  // SVNAdmin at the same time, but I do not see a better option
  // without APR already initialized
  if (g_inInit)
    return false;

  g_inInit = true;
  g_initEnv = env;

  apr_status_t status;

  /* C programs default to the "C" locale. But because svn is supposed
     to be i18n-aware, it should inherit the default locale of its
     environment.  */
  if (!setlocale(LC_ALL, ""))
    {
      if (stderr)
        {
          const char *env_vars[] = { "LC_ALL", "LC_CTYPE", "LANG", NULL };
          const char **env_var = &env_vars[0], *env_val = NULL;
          while (*env_var)
            {
              env_val = getenv(*env_var);
              if (env_val && env_val[0])
                break;
              ++env_var;
            }

          if (!*env_var)
            {
              /* Unlikely. Can setlocale fail if no env vars are set? */
              --env_var;
              env_val = "not set";
            }

          fprintf(stderr,
                  "%s: error: cannot set LC_ALL locale\n"
                  "%s: error: environment variable %s is %s\n"
                  "%s: error: please check that your locale name is "
                  "correct\n",
                  "svnjavahl", "svnjavahl", *env_var, env_val, "svnjavahl");
        }
      return FALSE;
    }

  /* Initialize the APR subsystem, and register an atexit() function
   * to Uninitialize that subsystem at program exit. */
  status = apr_initialize();
  if (status)
    {
      if (stderr)
        {
          char buf[1024];
          apr_strerror(status, buf, sizeof(buf) - 1);
          fprintf(stderr,
                  "%s: error: cannot initialize APR: %s\n",
                  "svnjavahl", buf);
        }
      return FALSE;
    }

  if (0 > atexit(apr_terminate))
    {
      if (stderr)
        fprintf(stderr,
                "%s: error: atexit registration failed\n",
                "svnjavahl");
      return FALSE;
    }

#ifdef ENABLE_NLS
#ifdef WIN32
  {
    WCHAR ucs2_path[MAX_PATH];
    char *utf8_path;
    const char *internal_path;
    apr_pool_t *pool;
    apr_status_t apr_err;
    apr_size_t inwords, outbytes;
    unsigned int outlength;

    apr_pool_create(&pool, 0);
    /* get dll name - our locale info will be in '../share/locale' */
    inwords = sizeof(ucs2_path) / sizeof(ucs2_path[0]);
    HINSTANCE moduleHandle = GetModuleHandle("libsvnjavahl-1");
    GetModuleFileNameW(moduleHandle, ucs2_path, inwords);
    inwords = lstrlenW(ucs2_path);
    outbytes = outlength = 3 * (inwords + 1);
    utf8_path = (char *)apr_palloc(pool, outlength);
    apr_err = apr_conv_ucs2_to_utf8((const apr_wchar_t *) ucs2_path,
                                    &inwords, utf8_path, &outbytes);
    if (!apr_err && (inwords > 0 || outbytes == 0))
      apr_err = APR_INCOMPLETE;
    if (apr_err)
      {
        if (stderr)
          fprintf(stderr, "Can't convert module path to UTF-8");
        return FALSE;
      }
    utf8_path[outlength - outbytes] = '\0';
    internal_path = svn_path_internal_style(utf8_path, pool);
    /* get base path name */
    internal_path = svn_path_dirname(internal_path, pool);
    internal_path = svn_path_join(internal_path, SVN_LOCALE_RELATIVE_PATH,
                                  pool);
    bindtextdomain(PACKAGE_NAME, internal_path);
    apr_pool_destroy(pool);
  }
#else
  bindtextdomain(PACKAGE_NAME, SVN_LOCALE_DIR);
#endif
  textdomain(PACKAGE_NAME);
#endif

  /* Create our top-level pool. */
  g_pool = svn_pool_create(NULL);

#if defined(WIN32) || defined(__CYGWIN__)
  /* See http://svn.collab.net/repos/svn/trunk/notes/asp-dot-net-hack.txt */
  /* ### This code really only needs to be invoked by consumers of
     ### the libsvn_wc library, which basically means SVNClient. */
  if (getenv ("SVN_ASP_DOT_NET_HACK"))
    {
      svn_error_t *err = svn_wc_set_adm_dir("_svn", g_pool);
      if (err)
        {
          if (stderr)
            {
              fprintf(stderr,
                      "%s: error: SVN_ASP_DOT_NET_HACK failed: %s\n",
                      "svnjavahl", err->message);
            }
          svn_error_clear(err);
          return FALSE;
        }
    }
#endif

  // Build all mutexes.
  g_finalizedObjectsMutex = new JNIMutex(g_pool);
  if (isExceptionThrown())
    return false;

  g_logMutex = new JNIMutex(g_pool);
  if (isExceptionThrown())
    return false;

  g_globalPoolMutext = new JNIMutex(g_pool);
  if (isExceptionThrown())
    return false;

  // initialized the thread local storage
  if (!JNIThreadData::initThreadData())
    return false;

  setEnv(env);
  if (isExceptionThrown())
    return false;

  g_initEnv = NULL;
  g_inInit = false;
  return true;
}

/**
 * Returns the global (not request specific) pool.
 * @return global pool
 */
apr_pool_t *JNIUtil::getPool()
{
  return g_pool;
}

/**
 * Return the mutex securing the global pool.
 * @return the mutex for the global pool
 */
JNIMutex *JNIUtil::getGlobalPoolMutex()
{
  return g_globalPoolMutext;
}

void JNIUtil::raiseThrowable(const char *name, const char *message)
{
  if (getLogLevel() >= errorLog)
    {
      JNICriticalSection cs(*g_logMutex);
      g_logStream << "Throwable raised <" << message << ">" << std::endl;
    }

  JNIEnv *env = getEnv();
  jclass clazz = env->FindClass(name);
  if (isJavaExceptionThrown())
    return;

  env->ThrowNew(clazz, message);
  setExceptionThrown();
  env->DeleteLocalRef(clazz);
}

jstring JNIUtil::makeSVNErrorMessage(svn_error_t *err)
{
  if (err == NULL)
    return NULL;
  std::string buffer;
  assembleErrorMessage(err, 0, APR_SUCCESS, buffer);
  jstring jmessage = makeJString(buffer.c_str());
  return jmessage;
}

void
JNIUtil::throwNativeException(const char *className, const char *msg,
                              const char *source, int aprErr)
{
  JNIEnv *env = getEnv();
  jclass clazz = env->FindClass(className);

  if (getLogLevel() >= exceptionLog)
    {
      JNICriticalSection cs(*g_logMutex);
      g_logStream << "Subversion JavaHL exception thrown, message:<";
      g_logStream << msg << ">";
      if (source)
        g_logStream << " source:<" << source << ">";
      if (aprErr != -1)
        g_logStream << " apr-err:<" << aprErr << ">";
      g_logStream << std::endl;
    }
  if (isJavaExceptionThrown())
    return;

  jstring jmessage = makeJString(msg);
  if (isJavaExceptionThrown())
    return;
  jstring jsource = makeJString(source);
  if (isJavaExceptionThrown())
    return;

  jmethodID mid = env->GetMethodID(clazz, "<init>",
                                   "(Ljava/lang/String;Ljava/lang/String;I)V");
  if (isJavaExceptionThrown())
    return;
  jobject nativeException = env->NewObject(clazz, mid, jmessage, jsource,
                                           static_cast<jint>(aprErr));
  if (isJavaExceptionThrown())
    return;

  env->DeleteLocalRef(clazz);
  if (isJavaExceptionThrown())
    return;

  env->DeleteLocalRef(jmessage);
  if (isJavaExceptionThrown())
    return;

  env->DeleteLocalRef(jsource);
  if (isJavaExceptionThrown())
    return;

  env->Throw(static_cast<jthrowable>(nativeException));
}

void JNIUtil::handleSVNError(svn_error_t *err)
{
  std::string msg;
  assembleErrorMessage(err, 0, APR_SUCCESS, msg);
  const char *source = NULL;
#ifdef SVN_DEBUG
  if (err->file)
    {
      std::ostringstream buf;
      buf << err->file;
      if (err->line > 0)
        buf << ':' << err->line;
      source = buf.str().c_str();
    }
#endif
  throwNativeException(JAVA_PACKAGE "/ClientException", msg.c_str(),
                       source, err->apr_err);
  svn_error_clear(err);
}

void JNIUtil::putFinalizedClient(SVNBase *object)
{
  enqueueForDeletion(object);
}

void JNIUtil::enqueueForDeletion(SVNBase *object)
{
  JNICriticalSection cs(*g_finalizedObjectsMutex);
  if (!isExceptionThrown())
    g_finalizedObjects.push_back(object);
}

/**
 * Handle an apr error (those are not expected) by throwing an error.
 * @param error the apr error number
 * @param op the apr function returning the error
 */
void JNIUtil::handleAPRError(int error, const char *op)
{
  char *buffer = getFormatBuffer();
  if (buffer == NULL)
    return;

  apr_snprintf(buffer, formatBufferSize,
               _("an error occurred in function %s with return value %d"),
               op, error);

  throwError(buffer);
}

/**
 * Return if an exception has been detected.
 * @return a exception has been detected
 */
bool JNIUtil::isExceptionThrown()
{
  // During init -> look in the global member.
  if (g_inInit)
    return g_initException;

  // Look in the thread local storage.
  JNIThreadData *data = JNIThreadData::getThreadData();
  return data == NULL || data->m_exceptionThrown;
}

/**
 * Store the JNI environment for this request in the thread local
 * storage.
 * @param env   the JNI environment
 */
void JNIUtil::setEnv(JNIEnv *env)
{
  JNIThreadData::pushNewThreadData();
  JNIThreadData *data = JNIThreadData::getThreadData();
  data->m_env = env;
  data->m_exceptionThrown = false;
}

/**
 * Return the JNI environment to use
 * @return the JNI environment
 */
JNIEnv *JNIUtil::getEnv()
{
  // During init -> look into the global variable.
  if (g_inInit)
    return g_initEnv;

  // Look in the thread local storage.
  JNIThreadData *data = JNIThreadData::getThreadData();
  return data->m_env;
}

/**
 * Check if a Java exception has been thrown.
 * @return is a Java exception has been thrown
 */
bool JNIUtil::isJavaExceptionThrown()
{
  JNIEnv *env = getEnv();
  if (env->ExceptionCheck())
    {
      // Retrieving the exception removes it so we rethrow it here.
      jthrowable exp = env->ExceptionOccurred();
      env->ExceptionDescribe();
      env->Throw(exp);
      env->DeleteLocalRef(exp);
      setExceptionThrown();
      return true;
    }
  return false;
}

const char *
JNIUtil::thrownExceptionToCString()
{
  const char *msg;
  JNIEnv *env = getEnv();
  if (env->ExceptionCheck())
    {
      jthrowable t = env->ExceptionOccurred();
      static jmethodID getMessage = 0;
      if (getMessage == 0)
        {
          jclass clazz = env->FindClass("java/lang/Throwable");
          getMessage = env->GetMethodID(clazz, "getMessage",
                                        "(V)Ljava/lang/String;");
          env->DeleteLocalRef(clazz);
        }
      jstring jmsg = (jstring) env->CallObjectMethod(t, getMessage);
      JNIStringHolder tmp(jmsg);
      msg = tmp.pstrdup(getRequestPool()->pool());
      // ### Conditionally add t.printStackTrace() to msg?
    }
  else
    {
      msg = NULL;
    }
  return msg;
}

/**
 * Create a Java string from a native UTF-8 string.
 * @param txt   native UTF-8 string
 * @return the Java string. It is a local reference, which should be deleted
 *         as soon a possible
 */
jstring JNIUtil::makeJString(const char *txt)
{
  if (txt == NULL)
    // A NULL pointer is equates to a null java.lang.String.
    return NULL;

  JNIEnv *env = getEnv();
  return env->NewStringUTF(txt);
}

void
JNIUtil::setExceptionThrown(bool flag)
{
  if (g_inInit)
    {
      // During global initialization, store any errors that occur
      // in a global variable (since thread-local storage may not
      // yet be available).
      g_initException = flag;
    }
  else
    {
      // When global initialization is complete, thread-local
      // storage should be available, so store the error there.
      JNIThreadData *data = JNIThreadData::getThreadData();
      data->m_exceptionThrown = flag;
    }
}

/**
 * Initialite the log file.
 * @param level the log level
 * @param the name of the log file
 */
void JNIUtil::initLogFile(int level, jstring path)
{
  // lock this operation
  JNICriticalSection cs(*g_logMutex);
  if (g_logLevel > noLog) // if the log file has been opened
    g_logStream.close();

  // remember the log level
  g_logLevel = level;
  JNIStringHolder myPath(path);
  if (g_logLevel > noLog) // if a new log file is needed
    {
      // open it
      g_logStream.open(myPath, std::ios::app);
    }
}

/**
 * Returns a buffer to format error messages.
 * @return a buffer for formating error messages
 */
char *JNIUtil::getFormatBuffer()
{
  if (g_inInit) // during init -> use the global buffer
    return g_initFormatBuffer;

  // use the buffer in the thread local storage
  JNIThreadData *data = JNIThreadData::getThreadData();
  if (data == NULL) // if that does not exists -> use the global buffer
    return g_initFormatBuffer;

  return data->m_formatBuffer;
}

/**
 * Returns the current log level.
 * @return the log level
 */
int JNIUtil::getLogLevel()
{
  return g_logLevel;
}

/**
 * Write a message to the log file if needed.
 * @param the log message
 */
void JNIUtil::logMessage(const char *message)
{
  // lock the log file
  JNICriticalSection cs(*g_logMutex);
  g_logStream << message << std::endl;
}

/**
 * Create a java.util.Date object from an apr time.
 * @param time  the apr time
 * @return the java.util.Date. This is a local reference.  Delete as
 *         soon as possible
 */
jobject JNIUtil::createDate(apr_time_t time)
{
  jlong javatime = time /1000;
  JNIEnv *env = getEnv();
  jclass clazz = env->FindClass("java/util/Date");
  if (isJavaExceptionThrown())
    return NULL;

  static jmethodID mid = 0;
  if (mid == 0)
    {
      mid = env->GetMethodID(clazz, "<init>", "(J)V");
      if (isJavaExceptionThrown())
        return NULL;
    }

  jobject ret = env->NewObject(clazz, mid, javatime);
  if (isJavaExceptionThrown())
    return NULL;

  env->DeleteLocalRef(clazz);
  if (isJavaExceptionThrown())
    return NULL;

  return ret;
}

/**
 * Return the request pool. The request pool will be destroyed after each
 * request (call).
 * @return the pool to be used for this request
 */
Pool *JNIUtil::getRequestPool()
{
  return JNIThreadData::getThreadData()->m_requestPool;
}

/**
 * Set the request pool in thread local storage.
 * @param pool  the request pool
 */
void JNIUtil::setRequestPool(Pool *pool)
{
  JNIThreadData::getThreadData()->m_requestPool = pool;
}

/**
 * Create a Java byte array from an array of characters.
 * @param data      the character array
 * @param length    the number of characters in the array
 */
jbyteArray JNIUtil::makeJByteArray(const signed char *data, int length)
{
  if (data == NULL || length == 0)
    // a NULL or empty will create no Java array
    return NULL;

  JNIEnv *env = getEnv();

  // Allocate the Java array.
  jbyteArray ret = env->NewByteArray(length);
  if (isJavaExceptionThrown())
    return NULL;

  // Access the bytes.
  jbyte *retdata = env->GetByteArrayElements(ret, NULL);
  if (isJavaExceptionThrown())
    return NULL;

  // Copy the bytes.
  memcpy(retdata, data, length);

  // Release the bytes.
  env->ReleaseByteArrayElements(ret, retdata, 0);
  if (isJavaExceptionThrown())
    return NULL;

  return ret;
}

/**
 * Build the error message from the svn error into buffer.  This
 * method calls itselft recursively for all the chained errors
 *
 * @param err               the subversion error
 * @param depth             the depth of the call, used for formating
 * @param parent_apr_err    the apr of the previous level, used for formating
 * @param buffer            the buffer where the formated error message will
 *                          be stored
 */
void JNIUtil::assembleErrorMessage(svn_error_t *err, int depth,
                                   apr_status_t parent_apr_err,
                                   std::string &buffer)
{
  // buffer for a single error message
  char errbuf[256];

  /* Pretty-print the error */
  /* Note: we can also log errors here someday. */

  /* When we're recursing, don't repeat the top-level message if its
   * the same as before. */
  if (depth == 0 || err->apr_err != parent_apr_err)
    {
      /* Is this a Subversion-specific error code? */
      if ((err->apr_err > APR_OS_START_USEERR)
          && (err->apr_err <= APR_OS_START_CANONERR))
        buffer.append(svn_strerror(err->apr_err, errbuf, sizeof(errbuf)));
      /* Otherwise, this must be an APR error code. */
      else
        buffer.append(apr_strerror(err->apr_err, errbuf, sizeof(errbuf)));
      buffer.append("\n");
    }
  if (err->message)
    buffer.append(_("svn: ")).append(err->message).append("\n");

  if (err->child)
    assembleErrorMessage(err->child, depth + 1, err->apr_err, buffer);

}

/**
 * Throw a Java NullPointerException.  Used when input parameters
 * which should not be null are that.
 *
 * @param message   the name of the parameter that is null
 */
void JNIUtil::throwNullPointerException(const char *message)
{
  if (getLogLevel() >= errorLog)
    logMessage("NullPointerException thrown");

  JNIEnv *env = getEnv();
  jclass clazz = env->FindClass("java/lang/NullPointerException");
  if (isJavaExceptionThrown())
    return;

  env->ThrowNew(clazz, message);
  setExceptionThrown();
  env->DeleteLocalRef(clazz);
}

svn_error_t *JNIUtil::preprocessPath(const char *&path, apr_pool_t *pool)
{
  /* URLs and wc-paths get treated differently. */
  if (svn_path_is_url(path))
    {
      /* No need to canonicalize a URL's case or path separators. */

      /* Convert to URI. */
      path = svn_path_uri_from_iri(path, pool);

      /* Auto-escape some ASCII characters. */
      path = svn_path_uri_autoescape(path, pool);

      /* The above doesn't guarantee a valid URI. */
      if (! svn_path_is_uri_safe(path))
        return svn_error_createf(SVN_ERR_BAD_URL, NULL,
                                 _("URL '%s' is not properly URI-encoded"),
                                 path);

      /* Verify that no backpaths are present in the URL. */
      if (svn_path_is_backpath_present(path))
        return svn_error_createf(SVN_ERR_BAD_URL, NULL,
                                 _("URL '%s' contains a '..' element"),
                                 path);

      /* strip any trailing '/' */
      path = svn_path_canonicalize(path, pool);
    }
  else  /* not a url, so treat as a path */
    {
      const char *apr_target;
      char *truenamed_target; /* APR-encoded */
      apr_status_t apr_err;

      /* canonicalize case, and change all separators to '/'. */
      SVN_ERR(svn_path_cstring_from_utf8(&apr_target, path, pool));
      apr_err = apr_filepath_merge(&truenamed_target, "", apr_target,
                                   APR_FILEPATH_TRUENAME, pool);

      if (!apr_err)
        /* We have a canonicalized APR-encoded target now. */
        apr_target = truenamed_target;
      else if (APR_STATUS_IS_ENOENT(apr_err))
        /* It's okay for the file to not exist, that just means we
           have to accept the case given to the client. We'll use
           the original APR-encoded target. */
        ;
      else
        return svn_error_createf(apr_err, NULL,
                                 _("Error resolving case of '%s'"),
                                 svn_path_local_style(path, pool));

      /* convert back to UTF-8. */
      SVN_ERR(svn_path_cstring_to_utf8(&path, apr_target, pool));
      path = svn_path_canonicalize(path, pool);

    }
  return NULL;
}
