#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "../src/mlp_priv.h"
#include "mlp_java_priv.h"


JNIEnv *mlp_java_get_env(JavaVM *jvm){
	JNIEnv *env ;

	int rc = (*jvm)->AttachCurrentThread(jvm, ((void **)&env), NULL) ;
	if (rc < 0){
		mlp_fatal("mlp_java: Can't attach current thread to JVM") ;
	}

    return env ;
}


int mlp_java_check_exception(JNIEnv *env){
	return (*env)->ExceptionCheck(env) == JNI_TRUE ;
}


void mlp_java_set_error_from_exception(JNIEnv *env, mlp_context *ctx, mlp_error err, const char *fmt, ...){
	char *format = strdup(fmt) ;
	jthrowable exc = (*env)->ExceptionOccurred(env) ;
	if (exc != NULL){
		(*env)->ExceptionClear(env) ;

		/* We must get the exception class name and message and reallocate a new format string */
		jclass exc_class = (*env)->GetObjectClass(env, exc) ;
		jmethodID mid = (*env)->GetMethodID(env, exc_class, "toString", "()Ljava/lang/String;") ;
		if ((mid == NULL)||(mlp_java_check_exception(env))){
			(*env)->ExceptionDescribe(env) ;
			mlp_fatal("mlp_java: Can't find method toString() for exception object") ;
		}
		jstring str = (jstring)(*env)->CallObjectMethod(env, exc_class, mid) ;
		if (mlp_java_check_exception(env)){
			(*env)->ExceptionDescribe(env) ;
			mlp_fatal("mlp_java: Can't call method toString() for exception object") ;
		}
		const char *c_str = (*env)->GetStringUTFChars(env, str, NULL) ;
		free(format) ;
		format = (char *)malloc((strlen(fmt) + strlen(c_str) + 32) * sizeof(char)) ;
		sprintf(format, "%s [%s]", fmt, c_str) ;
		(*env)->ReleaseStringUTFChars(env, str, c_str) ;
	}

	va_list va ;
	va_start(va, fmt) ;
	char *info = (char *)malloc(MLP_MAX_ERROR_MSG_LENGTH * sizeof(char)) ;
	vsnprintf(info, MLP_MAX_ERROR_MSG_LENGTH - 1, format, va) ;
	va_end(va) ;

	mlp_context_set_error(ctx, err, "%s", info) ;
	free(format) ;
	free(info) ;
}