/**************************************************************************/
/*  openxr_android_extension.cpp                                          */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
/*                                                                        */
/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
/*                                                                        */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
/**************************************************************************/

#include "openxr_android_extension.h"

#include "../../openxr_api.h"

#include "java_godot_wrapper.h"
#include "os_android.h"
#include "thread_jandroid.h"

#include <jni.h>
#include <openxr/openxr.h>
#include <openxr/openxr_platform.h>

OpenXRAndroidExtension *OpenXRAndroidExtension::singleton = nullptr;

OpenXRAndroidExtension *OpenXRAndroidExtension::get_singleton() {
	return singleton;
}

OpenXRAndroidExtension::OpenXRAndroidExtension() {
	singleton = this;
}

HashMap<String, bool *> OpenXRAndroidExtension::get_requested_extensions() {
	HashMap<String, bool *> request_extensions;

	request_extensions[XR_KHR_LOADER_INIT_ANDROID_EXTENSION_NAME] = &loader_init_extension_available;
	request_extensions[XR_KHR_ANDROID_CREATE_INSTANCE_EXTENSION_NAME] = &create_instance_extension_available;

	return request_extensions;
}

void OpenXRAndroidExtension::on_before_instance_created() {
	if (XR_FAILED(EXT_TRY_INIT_XR_FUNC(xrInitializeLoaderKHR))) {
		// XR_KHR_loader_init not supported on this platform
		return;
	}
	loader_init_extension_available = true;

	JNIEnv *env = get_jni_env();
	JavaVM *vm;
	env->GetJavaVM(&vm);
	jobject activity_object = env->NewGlobalRef(static_cast<OS_Android *>(OS::get_singleton())->get_godot_java()->get_activity());

	XrLoaderInitInfoAndroidKHR loader_init_info_android = {
		.type = XR_TYPE_LOADER_INIT_INFO_ANDROID_KHR,
		.next = nullptr,
		.applicationVM = vm,
		.applicationContext = activity_object
	};
	XrResult result = xrInitializeLoaderKHR((const XrLoaderInitInfoBaseHeaderKHR *)&loader_init_info_android);
	ERR_FAIL_COND_MSG(XR_FAILED(result), "Failed to call xrInitializeLoaderKHR");
}

// We're keeping the Android create info struct here to avoid including openxr_platform.h in a header, which would break other extensions.
// This is reasonably safe as the struct is only used during initialization and the extension is a singleton.
static XrInstanceCreateInfoAndroidKHR instance_create_info;

void *OpenXRAndroidExtension::set_instance_create_info_and_get_next_pointer(void *p_next_pointer) {
	if (!create_instance_extension_available) {
		if (!loader_init_extension_available) {
			WARN_PRINT("No Android extensions available, couldn't pass JVM and Activity to OpenXR");
		}
		return nullptr;
	}

	JNIEnv *env = get_jni_env();
	JavaVM *vm;
	env->GetJavaVM(&vm);
	jobject activity_object = env->NewGlobalRef(static_cast<OS_Android *>(OS::get_singleton())->get_godot_java()->get_activity());

	instance_create_info = {
		.type = XR_TYPE_INSTANCE_CREATE_INFO_ANDROID_KHR,
		.next = p_next_pointer,
		.applicationVM = vm,
		.applicationActivity = activity_object
	};
	return &instance_create_info;
}

OpenXRAndroidExtension::~OpenXRAndroidExtension() {
	singleton = nullptr;
}