/*
  * JNI utility functions
  *
  * Copyright (c) 2015-2016 Matthieu Bouron <matthieu.bouron stupeflix.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef AVCODEC_FFJNI_H
 #define AVCODEC_FFJNI_H
 
 #include <jni.h>
 
 /*

  * Attach permanently a JNI environment to the current thread and retrieve it.
  *
  * If successfully attached, the JNI environment will automatically be detached
  * at thread destruction.

  *
  * @param attached pointer to an integer that will be set to 1 if the
  * environment has been attached to the current thread or 0 if it is
  * already attached.
  * @param log_ctx context used for logging, can be NULL
  * @return the JNI environment on success, NULL otherwise
  */

 JNIEnv *ff_jni_get_env(void *log_ctx);

 
 /*
  * Convert a jstring to its utf characters equivalent.
  *
  * @param env JNI environment
  * @param string Java string to convert
  * @param log_ctx context used for logging, can be NULL
  * @return a pointer to an array of unicode characters on success, NULL
  * otherwise
  */
 char *ff_jni_jstring_to_utf_chars(JNIEnv *env, jstring string, void *log_ctx);
 
 /*
  * Convert utf chars to its jstring equivalent.
  *
  * @param env JNI environment
  * @param utf_chars a pointer to an array of unicode characters
  * @param log_ctx context used for logging, can be NULL
  * @return a Java string object on success, NULL otherwise
  */
 jstring ff_jni_utf_chars_to_jstring(JNIEnv *env, const char *utf_chars, void *log_ctx);
 
 /*
  * Extract the error summary from a jthrowable in the form of "className: errorMessage"
  *
  * @param env JNI environment
  * @param exception exception to get the summary from
  * @param error address pointing to the error, the value is updated if a
  * summary can be extracted
  * @param log_ctx context used for logging, can be NULL
  * @return 0 on success, < 0 otherwise
  */
 int ff_jni_exception_get_summary(JNIEnv *env, jthrowable exception, char **error, void *log_ctx);
 
 /*
  * Check if an exception has occurred,log it using av_log and clear it.
  *
  * @param env JNI environment
  * @param log value used to enable logging if an exception has occurred,
  * 0 disables logging, != 0 enables logging
  * @param log_ctx context used for logging, can be NULL
  */
 int ff_jni_exception_check(JNIEnv *env, int log, void *log_ctx);
 
 /*
  * Jni field type.
  */
 enum FFJniFieldType {
 
     FF_JNI_CLASS,
     FF_JNI_FIELD,
     FF_JNI_STATIC_FIELD,
     FF_JNI_METHOD,
     FF_JNI_STATIC_METHOD
 
 };
 
 /*
  * Jni field describing a class, a field or a method to be retrieved using
  * the ff_jni_init_jfields method.
  */
 struct FFJniField {
 
     const char *name;
     const char *method;
     const char *signature;
     enum FFJniFieldType type;
     int offset;
     int mandatory;
 
 };
 
 /*
  * Retrieve class references, field ids and method ids to an arbitrary structure.
  *
  * @param env JNI environment
  * @param jfields a pointer to an arbitrary structure where the different
  * fields are declared and where the FFJNIField mapping table offsets are
  * pointing to
  * @param jfields_mapping null terminated array of FFJNIFields describing
  * the class/field/method to be retrieved
  * @param global make the classes references global. It is the caller
  * responsibility to properly release global references.
  * @param log_ctx context used for logging, can be NULL
  * @return 0 on success, < 0 otherwise
  */
 int ff_jni_init_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx);
 
 /*
  * Delete class references, field ids and method ids of an arbitrary structure.
  *
  * @param env JNI environment
  * @param jfields a pointer to an arbitrary structure where the different
  * fields are declared and where the FFJNIField mapping table offsets are
  * pointing to
  * @param jfields_mapping null terminated array of FFJNIFields describing
  * the class/field/method to be deleted
  * @param global threat the classes references as global and delete them
  * accordingly
  * @param log_ctx context used for logging, can be NULL
  * @return 0 on success, < 0 otherwise
  */
 int ff_jni_reset_jfields(JNIEnv *env, void *jfields, const struct FFJniField *jfields_mapping, int global, void *log_ctx);
 
 #endif /* AVCODEC_FFJNI_H */