/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2010 Sam Lantinga

    This library 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.

    This library 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 this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

/*******************************************************************************

 This file links the Java side of Android with libsdl

*******************************************************************************/

#include <jni.h>

#include <android/log.h>

/*******************************************************************************

                               Globals

*******************************************************************************/

JavaVM* mVM = NULL;

JNIEnv* mEnv = NULL;

JNIEnv* mAudioThreadEnv = NULL; //See the note below for why this is necessary

//Main activity

jclass mActivityInstance;

//method signatures

jmethodID midCreateGLContext;

jmethodID midFlipBuffers;

jmethodID midEnableFeature;

jmethodID midUpdateAudio;

extern "C" int Android_OnKeyDown(int keycode);

extern "C" int Android_OnKeyUp(int keycode);

extern "C" void Android_SetScreenResolution(int width, int height);

extern "C" void Android_OnResize(int width, int height, int format);

extern "C" int SDL_SendQuit();

extern "C" void Android_EnableFeature(int featureid, bool enabled);

//If we're not the active app, don't try to render

bool bRenderingEnabled = false;

//Feature IDs

static const int FEATURE_AUDIO = 1;

static const int FEATURE_ACCEL = 2;

//Accelerometer data storage

float fLastAccelerometer[3];

/*******************************************************************************

                 Functions called by JNI

*******************************************************************************/

// Library init

extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved)

{

    mVM = vm;

    return JNI_VERSION_1_4;

}

// Called before SDL_main() to initialize JNI bindings

extern "C" void SDL_Android_Init(JNIEnv* env)

{

    mEnv = env;

    __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL_Android_Init()");

    jclass cls = mEnv->FindClass ("org/libsdl/app/SDLActivity"); 

    mActivityInstance = cls;

    midCreateGLContext = mEnv->GetStaticMethodID(cls,"createGLContext","()V");

    midFlipBuffers = mEnv->GetStaticMethodID(cls,"flipBuffers","()V");

    midEnableFeature = mEnv->GetStaticMethodID(cls,"enableFeature","(II)V");

    midUpdateAudio = mEnv->GetStaticMethodID(cls,"updateAudio","([B)V");

    if(!midCreateGLContext || !midFlipBuffers || !midEnableFeature ||

        !midUpdateAudio) {

        __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: Bad mids\n");

    } else {

#ifdef DEBUG

        __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: Good mids\n");

#endif

    }

}

// Keydown

extern "C" void Java_org_libsdl_app_SDLActivity_onNativeKeyDown(JNIEnv* env, 

               jobject obj, jint keycode)

{

    int r = Android_OnKeyDown(keycode);

#ifdef DEBUG

    __android_log_print(ANDROID_LOG_INFO, "SDL", 

                        "SDL: native key down %d, %d\n", keycode, r);

#endif

}

// Keyup

extern "C" void Java_org_libsdl_app_SDLActivity_onNativeKeyUp(JNIEnv* env, 

               jobject obj, jint keycode)

{

    int r = Android_OnKeyUp(keycode);

#ifdef DEBUG

    __android_log_print(ANDROID_LOG_INFO, "SDL", 

                        "SDL: native key up %d, %d\n", keycode, r);

#endif

}

// Touch

extern "C" void Java_org_libsdl_app_SDLActivity_onNativeTouch(JNIEnv* env, 

               jobject obj, jint action, jfloat x, jfloat y, jfloat p)

{

#ifdef DEBUG

    __android_log_print(ANDROID_LOG_INFO, "SDL", 

                        "SDL: native touch event %d @ %f/%f, pressure %f\n", 

                        action, x, y, p);

#endif

    //TODO: Pass this off to the SDL multitouch stuff

}

// Quit

extern "C" void Java_org_libsdl_app_SDLActivity_nativeQuit( JNIEnv*  env, 

                                                                jobject obj )

{    

    // Stop rendering as we're no longer in the foreground

    bRenderingEnabled = false;

    // Inject a SDL_QUIT event

    SDL_SendQuit();

}

// Screen size

extern "C" void Java_org_libsdl_app_SDLActivity_nativeSetScreenSize(

                JNIEnv*  env, jobject obj, jint width, jint height)

{

    __android_log_print(ANDROID_LOG_INFO, "SDL", 

                        "SDL: Set screen size on init: %d/%d\n", width, height);

    Android_SetScreenResolution(width, height);

}

// Resize

extern "C" void Java_org_libsdl_app_SDLActivity_onNativeResize(

                                        JNIEnv*  env, jobject obj, jint width, 

                                        jint height, jint format)

{

    Android_OnResize(width, height, format);

}

extern "C" void Java_org_libsdl_app_SDLActivity_onNativeAccel(

                                        JNIEnv*  env, jobject obj,

                                        jfloat x, jfloat y, jfloat z)

{

    fLastAccelerometer[0] = x;

    fLastAccelerometer[1] = y;

    fLastAccelerometer[2] = z;   

}

/*******************************************************************************

             Functions called by SDL into Java

*******************************************************************************/

extern "C" void Android_CreateContext()

{

    __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: sdl_create_context()\n");

    bRenderingEnabled = true;

    mEnv->CallStaticVoidMethod(mActivityInstance, midCreateGLContext ); 

}

extern "C" void Android_Render()

{

    if (!bRenderingEnabled) {

        return;

    }

    // When we get here, we've accumulated a full frame    

    mEnv->CallStaticVoidMethod(mActivityInstance, midFlipBuffers); 

}

extern "C" void Android_EnableFeature(int featureid, bool enabled)

{

    mEnv->CallStaticVoidMethod(mActivityInstance, midEnableFeature, 

                                featureid, (int)enabled); 

}

extern "C" void Android_UpdateAudioBuffer(unsigned char *buf, int len)

{

    //Annoyingly we can't just call into Java from any thread. Because the audio

    //callback is dispatched from the SDL audio thread (that wasn't made from

    //java, we have to do some magic here to let the JVM know about the thread.

    //Because everything it touches on the Java side is static anyway, it's 

    //not a big deal, just annoying.

    if(!mAudioThreadEnv) {

        __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: Need to set up audio thread env\n");

        mVM->AttachCurrentThread(&mAudioThreadEnv, NULL);

        __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: ok\n");

    }

    jbyteArray arr = mAudioThreadEnv->NewByteArray(len);

    //blah. We probably should rework this so we avoid the copy. 

    mAudioThreadEnv->SetByteArrayRegion(arr, 0, len, (jbyte *)buf);

    __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: copied\n");

    mAudioThreadEnv->CallStaticVoidMethod(  mActivityInstance, 

                                            midUpdateAudio, arr );

    __android_log_print(ANDROID_LOG_INFO, "SDL", "SDL: invoked\n");

}