/*************************************************************************/
/*  gd_mono.cpp                                                          */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2018 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2018 Godot Engine contributors (cf. AUTHORS.md)    */
/*                                                                       */
/* 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 "gd_mono.h"

#include <mono/metadata/exception.h>
#include <mono/metadata/mono-config.h>
#include <mono/metadata/mono-debug.h>
#include <mono/metadata/mono-gc.h>

#include "os/dir_access.h"
#include "os/file_access.h"
#include "os/os.h"
#include "os/thread.h"
#include "project_settings.h"

#include "../csharp_script.h"
#include "../utils/path_utils.h"
#include "gd_mono_utils.h"

#ifdef TOOLS_ENABLED
#include "../editor/godotsharp_editor.h"
#include "main/main.h"
#endif

void gdmono_unhandled_exception_hook(MonoObject *exc, void *user_data) {

	(void)user_data; // UNUSED

	GDMonoUtils::print_unhandled_exception(exc);
	abort();
}

#ifdef MONO_PRINT_HANDLER_ENABLED
void gdmono_MonoPrintCallback(const char *string, mono_bool is_stdout) {

	if (is_stdout) {
		OS::get_singleton()->print(string);
	} else {
		OS::get_singleton()->printerr(string);
	}
}
#endif

GDMono *GDMono::singleton = NULL;

#ifdef DEBUG_ENABLED
static bool _wait_for_debugger_msecs(uint32_t p_msecs) {

	do {
		if (mono_is_debugger_attached())
			return true;

		int last_tick = OS::get_singleton()->get_ticks_msec();

		OS::get_singleton()->delay_usec((p_msecs < 25 ? p_msecs : 25) * 1000);

		int tdiff = OS::get_singleton()->get_ticks_msec() - last_tick;

		if (tdiff > p_msecs) {
			p_msecs = 0;
		} else {
			p_msecs -= tdiff;
		}
	} while (p_msecs > 0);

	return mono_is_debugger_attached();
}
#endif

#ifdef DEBUG_ENABLED
void gdmono_debug_init() {

	mono_debug_init(MONO_DEBUG_FORMAT_MONO);

	int da_port = GLOBAL_DEF("mono/debugger_agent/port", 23685);
	bool da_suspend = GLOBAL_DEF("mono/debugger_agent/wait_for_debugger", false);
	int da_timeout = GLOBAL_DEF("mono/debugger_agent/wait_timeout", 3000);

#ifdef TOOLS_ENABLED
	if (Engine::get_singleton()->is_editor_hint() ||
			ProjectSettings::get_singleton()->get_resource_path().empty() ||
			Main::is_project_manager()) {
		return;
	}
#endif

	CharString da_args = String("--debugger-agent=transport=dt_socket,address=127.0.0.1:" + itos(da_port) +
								",embedding=1,server=y,suspend=" + (da_suspend ? "y,timeout=" + itos(da_timeout) : "n"))
								 .utf8();
	// --debugger-agent=help
	const char *options[] = {
		"--soft-breakpoints",
		da_args.get_data()
	};
	mono_jit_parse_options(2, (char **)options);
}
#endif

void GDMono::initialize() {

	ERR_FAIL_NULL(Engine::get_singleton());

	OS::get_singleton()->print("Mono: Initializing module...\n");

#ifdef DEBUG_METHODS_ENABLED
	_initialize_and_check_api_hashes();
#endif

	GDMonoLog::get_singleton()->initialize();

#ifdef MONO_PRINT_HANDLER_ENABLED
	mono_trace_set_print_handler(gdmono_MonoPrintCallback);
	mono_trace_set_printerr_handler(gdmono_MonoPrintCallback);
#endif

#ifdef WINDOWS_ENABLED
	mono_reg_info = MonoRegUtils::find_mono();

	CharString assembly_dir;
	CharString config_dir;

	if (mono_reg_info.assembly_dir.length() && DirAccess::exists(mono_reg_info.assembly_dir)) {
		assembly_dir = mono_reg_info.assembly_dir.utf8();
	}

	if (mono_reg_info.config_dir.length() && DirAccess::exists(mono_reg_info.config_dir)) {
		config_dir = mono_reg_info.config_dir.utf8();
	}

	mono_set_dirs(assembly_dir.length() ? assembly_dir.get_data() : NULL,
			config_dir.length() ? config_dir.get_data() : NULL);
#else
	mono_set_dirs(NULL, NULL);
#endif

	GDMonoAssembly::initialize();

#ifdef DEBUG_ENABLED
	gdmono_debug_init();
#endif

	mono_config_parse(NULL);

	root_domain = mono_jit_init_version("GodotEngine.RootDomain", "v4.0.30319");

	ERR_EXPLAIN("Mono: Failed to initialize runtime");
	ERR_FAIL_NULL(root_domain);

	GDMonoUtils::set_main_thread(GDMonoUtils::get_current_thread());

	runtime_initialized = true;

	OS::get_singleton()->print("Mono: Runtime initialized\n");

	// mscorlib assembly MUST be present at initialization
	ERR_EXPLAIN("Mono: Failed to load mscorlib assembly");
	ERR_FAIL_COND(!_load_corlib_assembly());

#ifdef TOOLS_ENABLED
	// The tools domain must be loaded here, before the scripts domain.
	// Otherwise domain unload on the scripts domain will hang indefinitely.

	ERR_EXPLAIN("Mono: Failed to load tools domain");
	ERR_FAIL_COND(_load_tools_domain() != OK);

	// TODO move to editor init callback, and do it lazily when required before editor init (e.g.: bindings generation)
	ERR_EXPLAIN("Mono: Failed to load Editor Tools assembly");
	ERR_FAIL_COND(!_load_editor_tools_assembly());
#endif

	ERR_EXPLAIN("Mono: Failed to load scripts domain");
	ERR_FAIL_COND(_load_scripts_domain() != OK);

#ifdef DEBUG_ENABLED
	bool debugger_attached = _wait_for_debugger_msecs(500);
	if (!debugger_attached && OS::get_singleton()->is_stdout_verbose())
		OS::get_singleton()->printerr("Mono: Debugger wait timeout\n");
#endif

	_register_internal_calls();

	// The following assemblies are not required at initialization
	_load_all_script_assemblies();

	mono_install_unhandled_exception_hook(gdmono_unhandled_exception_hook, NULL);

	OS::get_singleton()->print("Mono: INITIALIZED\n");
}

#ifndef MONO_GLUE_DISABLED
namespace GodotSharpBindings {

uint64_t get_core_api_hash();
uint64_t get_editor_api_hash();

void register_generated_icalls();
} // namespace GodotSharpBindings
#endif

void GDMono::_register_internal_calls() {
#ifndef MONO_GLUE_DISABLED
	GodotSharpBindings::register_generated_icalls();
#endif

#ifdef TOOLS_ENABLED
	GodotSharpBuilds::_register_internal_calls();
#endif
}

#ifdef DEBUG_METHODS_ENABLED
void GDMono::_initialize_and_check_api_hashes() {

	api_core_hash = ClassDB::get_api_hash(ClassDB::API_CORE);

#ifndef MONO_GLUE_DISABLED
	if (api_core_hash != GodotSharpBindings::get_core_api_hash()) {
		ERR_PRINT("Mono: Core API hash mismatch!");
	}
#endif

#ifdef TOOLS_ENABLED
	api_editor_hash = ClassDB::get_api_hash(ClassDB::API_EDITOR);

#ifndef MONO_GLUE_DISABLED
	if (api_editor_hash != GodotSharpBindings::get_editor_api_hash()) {
		ERR_PRINT("Mono: Editor API hash mismatch!");
	}
#endif

#endif // TOOLS_ENABLED
}
#endif // DEBUG_METHODS_ENABLED

void GDMono::add_assembly(uint32_t p_domain_id, GDMonoAssembly *p_assembly) {

	assemblies[p_domain_id][p_assembly->get_name()] = p_assembly;
}

GDMonoAssembly **GDMono::get_loaded_assembly(const String &p_name) {

	MonoDomain *domain = mono_domain_get();
	uint32_t domain_id = domain ? mono_domain_get_id(domain) : 0;
	return assemblies[domain_id].getptr(p_name);
}

bool GDMono::_load_assembly(const String &p_name, GDMonoAssembly **r_assembly) {

	CRASH_COND(!r_assembly);

	if (OS::get_singleton()->is_stdout_verbose())
		OS::get_singleton()->print((String() + "Mono: Loading assembly " + p_name + "...\n").utf8());

	MonoImageOpenStatus status = MONO_IMAGE_OK;
	MonoAssemblyName *aname = mono_assembly_name_new(p_name.utf8());
	MonoAssembly *assembly = mono_assembly_load_full(aname, NULL, &status, false);
	mono_assembly_name_free(aname);

	if (!assembly)
		return false;

	uint32_t domain_id = mono_domain_get_id(mono_domain_get());

	GDMonoAssembly **stored_assembly = assemblies[domain_id].getptr(p_name);

	ERR_FAIL_COND_V(status != MONO_IMAGE_OK, false);
	ERR_FAIL_COND_V(stored_assembly == NULL, false);

	ERR_FAIL_COND_V((*stored_assembly)->get_assembly() != assembly, false);
	*r_assembly = *stored_assembly;

	if (OS::get_singleton()->is_stdout_verbose())
		OS::get_singleton()->print(String("Mono: Assembly " + p_name + " loaded from path: " + (*r_assembly)->get_path() + "\n").utf8());

	return true;
}

bool GDMono::_load_corlib_assembly() {

	if (corlib_assembly)
		return true;

	bool success = _load_assembly("mscorlib", &corlib_assembly);

	if (success)
		GDMonoUtils::update_corlib_cache();

	return success;
}

bool GDMono::_load_core_api_assembly() {

	if (api_assembly)
		return true;

	bool success = _load_assembly(API_ASSEMBLY_NAME, &api_assembly);

	if (success)
		GDMonoUtils::update_godot_api_cache();

	return success;
}

#ifdef TOOLS_ENABLED
bool GDMono::_load_editor_api_assembly() {

	if (editor_api_assembly)
		return true;

	return _load_assembly(EDITOR_API_ASSEMBLY_NAME, &editor_api_assembly);
}
#endif

#ifdef TOOLS_ENABLED
bool GDMono::_load_editor_tools_assembly() {

	if (editor_tools_assembly)
		return true;

	_GDMONO_SCOPE_DOMAIN_(tools_domain)

	return _load_assembly(EDITOR_TOOLS_ASSEMBLY_NAME, &editor_tools_assembly);
}
#endif

bool GDMono::_load_project_assembly() {

	if (project_assembly)
		return true;

	String name = ProjectSettings::get_singleton()->get("application/config/name");
	if (name.empty()) {
		name = "UnnamedProject";
	}

	bool success = _load_assembly(name, &project_assembly);

	if (success)
		mono_assembly_set_main(project_assembly->get_assembly());

	return success;
}

bool GDMono::_load_all_script_assemblies() {

#ifndef MONO_GLUE_DISABLED
	if (!_load_core_api_assembly()) {
		if (OS::get_singleton()->is_stdout_verbose())
			OS::get_singleton()->printerr("Mono: Failed to load Core API assembly\n");
		return false;
	} else {
#ifdef TOOLS_ENABLED
		if (!_load_editor_api_assembly()) {
			if (OS::get_singleton()->is_stdout_verbose())
				OS::get_singleton()->printerr("Mono: Failed to load Editor API assembly\n");
			return false;
		}
#endif
	}

	if (!_load_project_assembly()) {
		if (OS::get_singleton()->is_stdout_verbose())
			OS::get_singleton()->printerr("Mono: Failed to load project assembly\n");
		return false;
	}

	return true;
#else
	if (OS::get_singleton()->is_stdout_verbose())
		OS::get_singleton()->print("Mono: Glue disbled, ignoring script assemblies\n");

	return true;
#endif
}

Error GDMono::_load_scripts_domain() {

	ERR_FAIL_COND_V(scripts_domain != NULL, ERR_BUG);

	if (OS::get_singleton()->is_stdout_verbose()) {
		OS::get_singleton()->print("Mono: Loading scripts domain...\n");
	}

	scripts_domain = GDMonoUtils::create_domain("GodotEngine.ScriptsDomain");

	ERR_EXPLAIN("Mono: Could not create scripts app domain");
	ERR_FAIL_NULL_V(scripts_domain, ERR_CANT_CREATE);

	mono_domain_set(scripts_domain, true);

	return OK;
}

Error GDMono::_unload_scripts_domain() {

	ERR_FAIL_NULL_V(scripts_domain, ERR_BUG);

	if (OS::get_singleton()->is_stdout_verbose()) {
		OS::get_singleton()->print("Mono: Unloading scripts domain...\n");
	}

	_GodotSharp::get_singleton()->_dispose_callback();

	if (mono_domain_get() != root_domain)
		mono_domain_set(root_domain, true);

	mono_gc_collect(mono_gc_max_generation());

	finalizing_scripts_domain = true;
	mono_domain_finalize(scripts_domain, 2000);
	finalizing_scripts_domain = false;

	mono_gc_collect(mono_gc_max_generation());

	_domain_assemblies_cleanup(mono_domain_get_id(scripts_domain));

	api_assembly = NULL;
	project_assembly = NULL;
#ifdef TOOLS_ENABLED
	editor_api_assembly = NULL;
#endif

	MonoDomain *domain = scripts_domain;
	scripts_domain = NULL;

	_GodotSharp::get_singleton()->_dispose_callback();

	MonoObject *ex = NULL;
	mono_domain_try_unload(domain, &ex);

	if (ex) {
		ERR_PRINT("Exception thrown when unloading scripts domain:");
		mono_print_unhandled_exception(ex);
		return FAILED;
	}

	return OK;
}

#ifdef TOOLS_ENABLED
Error GDMono::_load_tools_domain() {

	ERR_FAIL_COND_V(tools_domain != NULL, ERR_BUG);

	if (OS::get_singleton()->is_stdout_verbose()) {
		OS::get_singleton()->print("Mono: Loading tools domain...\n");
	}

	tools_domain = GDMonoUtils::create_domain("GodotEngine.ToolsDomain");

	ERR_EXPLAIN("Mono: Could not create tools app domain");
	ERR_FAIL_NULL_V(tools_domain, ERR_CANT_CREATE);

	return OK;
}
#endif

#ifdef TOOLS_ENABLED
Error GDMono::reload_scripts_domain() {

	ERR_FAIL_COND_V(!runtime_initialized, ERR_BUG);

	if (scripts_domain) {
		Error err = _unload_scripts_domain();
		if (err != OK) {
			ERR_PRINT("Mono: Failed to unload scripts domain");
			return err;
		}
	}

	Error err = _load_scripts_domain();
	if (err != OK) {
		ERR_PRINT("Mono: Failed to load scripts domain");
		return err;
	}

	if (!_load_all_script_assemblies()) {
		if (OS::get_singleton()->is_stdout_verbose())
			OS::get_singleton()->printerr("Mono: Failed to load script assemblies\n");
		return ERR_CANT_OPEN;
	}

	return OK;
}
#endif

GDMonoClass *GDMono::get_class(MonoClass *p_raw_class) {

	MonoImage *image = mono_class_get_image(p_raw_class);

	if (image == corlib_assembly->get_image())
		return corlib_assembly->get_class(p_raw_class);

	uint32_t domain_id = mono_domain_get_id(mono_domain_get());
	HashMap<String, GDMonoAssembly *> &domain_assemblies = assemblies[domain_id];

	const String *k = NULL;
	while ((k = domain_assemblies.next(k))) {
		GDMonoAssembly *assembly = domain_assemblies.get(*k);
		if (assembly->get_image() == image) {
			GDMonoClass *klass = assembly->get_class(p_raw_class);

			if (klass)
				return klass;
		}
	}

	return NULL;
}

void GDMono::_domain_assemblies_cleanup(uint32_t p_domain_id) {

	HashMap<String, GDMonoAssembly *> &domain_assemblies = assemblies[p_domain_id];

	const String *k = NULL;
	while ((k = domain_assemblies.next(k))) {
		memdelete(domain_assemblies.get(*k));
	}

	assemblies.erase(p_domain_id);
}

GDMono::GDMono() {

	singleton = this;

	gdmono_log = memnew(GDMonoLog);

	runtime_initialized = false;
	finalizing_scripts_domain = false;

	root_domain = NULL;
	scripts_domain = NULL;
#ifdef TOOLS_ENABLED
	tools_domain = NULL;
#endif

	corlib_assembly = NULL;
	api_assembly = NULL;
	project_assembly = NULL;
#ifdef TOOLS_ENABLED
	editor_api_assembly = NULL;
	editor_tools_assembly = NULL;
#endif

#ifdef DEBUG_METHODS_ENABLED
	api_core_hash = 0;
#ifdef TOOLS_ENABLED
	api_editor_hash = 0;
#endif
#endif
}

GDMono::~GDMono() {

	if (runtime_initialized) {

		if (scripts_domain) {

			Error err = _unload_scripts_domain();
			if (err != OK) {
				WARN_PRINT("Mono: Failed to unload scripts domain");
			}
		}

		const uint32_t *k = NULL;
		while ((k = assemblies.next(k))) {
			HashMap<String, GDMonoAssembly *> &domain_assemblies = assemblies.get(*k);

			const String *kk = NULL;
			while ((kk = domain_assemblies.next(kk))) {
				memdelete(domain_assemblies.get(*kk));
			}
		}
		assemblies.clear();

		GDMonoUtils::clear_cache();

		OS::get_singleton()->print("Mono: Runtime cleanup...\n");

		runtime_initialized = false;
		mono_jit_cleanup(root_domain);
	}

	if (gdmono_log)
		memdelete(gdmono_log);

	singleton = NULL;
}

_GodotSharp *_GodotSharp::singleton = NULL;

void _GodotSharp::_dispose_object(Object *p_object) {

	if (p_object->get_script_instance()) {
		CSharpInstance *cs_instance = CAST_CSHARP_INSTANCE(p_object->get_script_instance());
		if (cs_instance) {
			cs_instance->mono_object_disposed();
			return;
		}
	}

	// Unsafe refcount decrement. The managed instance also counts as a reference.
	// See: CSharpLanguage::alloc_instance_binding_data(Object *p_object)
	if (Object::cast_to<Reference>(p_object)->unreference()) {
		memdelete(p_object);
	}
}

void _GodotSharp::_dispose_callback() {

#ifndef NO_THREADS
	queue_mutex->lock();
#endif

	for (List<Object *>::Element *E = obj_delete_queue.front(); E; E = E->next()) {
		_dispose_object(E->get());
	}

	for (List<NodePath *>::Element *E = np_delete_queue.front(); E; E = E->next()) {
		memdelete(E->get());
	}

	for (List<RID *>::Element *E = rid_delete_queue.front(); E; E = E->next()) {
		memdelete(E->get());
	}

	obj_delete_queue.clear();
	np_delete_queue.clear();
	rid_delete_queue.clear();
	queue_empty = true;

#ifndef NO_THREADS
	queue_mutex->unlock();
#endif
}

void _GodotSharp::attach_thread() {

	GDMonoUtils::attach_current_thread();
}

void _GodotSharp::detach_thread() {

	GDMonoUtils::detach_current_thread();
}

bool _GodotSharp::is_finalizing_domain() {

	return GDMono::get_singleton()->is_finalizing_scripts_domain();
}

bool _GodotSharp::is_domain_loaded() {

	return GDMono::get_singleton()->get_scripts_domain() != NULL;
}

#define ENQUEUE_FOR_DISPOSAL(m_queue, m_inst)                                   \
	m_queue.push_back(m_inst);                                                  \
	if (queue_empty) {                                                          \
		queue_empty = false;                                                    \
		if (!is_finalizing_domain()) { /* call_deferred may not be safe here */ \
			call_deferred("_dispose_callback");                                 \
		}                                                                       \
	}

void _GodotSharp::queue_dispose(MonoObject *p_mono_object, Object *p_object) {

	if (GDMonoUtils::is_main_thread() && !GDMono::get_singleton()->is_finalizing_scripts_domain()) {
		_dispose_object(p_object);
	} else {
#ifndef NO_THREADS
		queue_mutex->lock();
#endif

		// This is our last chance to invoke notification predelete (this is being called from the finalizer)
		// We must use the MonoObject* passed by the finalizer, because the weak GC handle target returns NULL at this point
		CSharpInstance *si = CAST_CSHARP_INSTANCE(p_object->get_script_instance());
		if (si) {
			si->call_notification_no_check(p_mono_object, Object::NOTIFICATION_PREDELETE);
		}

		ENQUEUE_FOR_DISPOSAL(obj_delete_queue, p_object);

#ifndef NO_THREADS
		queue_mutex->unlock();
#endif
	}
}

void _GodotSharp::queue_dispose(NodePath *p_node_path) {

	if (GDMonoUtils::is_main_thread() && !GDMono::get_singleton()->is_finalizing_scripts_domain()) {
		memdelete(p_node_path);
	} else {
#ifndef NO_THREADS
		queue_mutex->lock();
#endif

		ENQUEUE_FOR_DISPOSAL(np_delete_queue, p_node_path);

#ifndef NO_THREADS
		queue_mutex->unlock();
#endif
	}
}

void _GodotSharp::queue_dispose(RID *p_rid) {

	if (GDMonoUtils::is_main_thread() && !GDMono::get_singleton()->is_finalizing_scripts_domain()) {
		memdelete(p_rid);
	} else {
#ifndef NO_THREADS
		queue_mutex->lock();
#endif

		ENQUEUE_FOR_DISPOSAL(rid_delete_queue, p_rid);

#ifndef NO_THREADS
		queue_mutex->unlock();
#endif
	}
}

void _GodotSharp::_bind_methods() {

	ClassDB::bind_method(D_METHOD("attach_thread"), &_GodotSharp::attach_thread);
	ClassDB::bind_method(D_METHOD("detach_thread"), &_GodotSharp::detach_thread);

	ClassDB::bind_method(D_METHOD("is_finalizing_domain"), &_GodotSharp::is_finalizing_domain);
	ClassDB::bind_method(D_METHOD("is_domain_loaded"), &_GodotSharp::is_domain_loaded);

	ClassDB::bind_method(D_METHOD("_dispose_callback"), &_GodotSharp::_dispose_callback);
}

_GodotSharp::_GodotSharp() {

	singleton = this;
	queue_empty = true;
#ifndef NO_THREADS
	queue_mutex = Mutex::create();
#endif
}

_GodotSharp::~_GodotSharp() {

	singleton = NULL;

	if (queue_mutex) {
		memdelete(queue_mutex);
	}
}