/*************************************************************************/
/*  csharp_script.h                                                      */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                      https://godotengine.org                          */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur.                 */
/* Copyright (c) 2014-2021 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.                */
/*************************************************************************/

#ifndef CSHARP_SCRIPT_H
#define CSHARP_SCRIPT_H

#include "core/doc_data.h"
#include "core/io/resource_loader.h"
#include "core/io/resource_saver.h"
#include "core/object/script_language.h"
#include "core/templates/self_list.h"

#include "mono_gc_handle.h"
#include "mono_gd/gd_mono.h"
#include "mono_gd/gd_mono_header.h"
#include "mono_gd/gd_mono_internals.h"

#ifdef TOOLS_ENABLED
#include "editor/editor_plugin.h"
#endif

class CSharpScript;
class CSharpInstance;
class CSharpLanguage;

#ifdef NO_SAFE_CAST
template <typename TScriptInstance, typename TScriptLanguage>
TScriptInstance *cast_script_instance(ScriptInstance *p_inst) {
	if (!p_inst)
		return nullptr;
	return p_inst->get_language() == TScriptLanguage::get_singleton() ? static_cast<TScriptInstance *>(p_inst) : nullptr;
}
#else
template <typename TScriptInstance, typename TScriptLanguage>
TScriptInstance *cast_script_instance(ScriptInstance *p_inst) {
	return dynamic_cast<TScriptInstance *>(p_inst);
}
#endif

#define CAST_CSHARP_INSTANCE(m_inst) (cast_script_instance<CSharpInstance, CSharpLanguage>(m_inst))

struct DotNetScriptLookupInfo {
	String class_namespace;
	String class_name;
	GDMonoClass *script_class = nullptr;

	DotNetScriptLookupInfo() {} // Required by HashMap...

	DotNetScriptLookupInfo(const String &p_class_namespace, const String &p_class_name, GDMonoClass *p_script_class) :
			class_namespace(p_class_namespace), class_name(p_class_name), script_class(p_script_class) {
	}
};

class CSharpScript : public Script {
	GDCLASS(CSharpScript, Script);

public:
	struct SignalParameter {
		String name;
		Variant::Type type;
		bool nil_is_variant = false;
	};

	struct EventSignal {
		GDMonoField *field = nullptr;
		GDMonoMethod *invoke_method = nullptr;
		Vector<SignalParameter> parameters;
	};

private:
	friend class CSharpInstance;
	friend class CSharpLanguage;
	friend struct CSharpScriptDepSort;

	bool tool = false;
	bool valid = false;

	bool builtin;

	GDMonoClass *base = nullptr;
	GDMonoClass *native = nullptr;
	GDMonoClass *script_class = nullptr;

	Ref<CSharpScript> base_cache; // TODO what's this for?

	Set<Object *> instances;

#ifdef GD_MONO_HOT_RELOAD
	struct StateBackup {
		// TODO
		// Replace with buffer containing the serialized state of managed scripts.
		// Keep variant state backup to use only with script instance placeholders.
		List<Pair<StringName, Variant>> properties;
		List<Pair<StringName, Array>> event_signals;
	};

	Set<ObjectID> pending_reload_instances;
	Map<ObjectID, StateBackup> pending_reload_state;
	StringName tied_class_name_for_reload;
	StringName tied_class_namespace_for_reload;
#endif

	String source;
	StringName name;

	SelfList<CSharpScript> script_list = this;

	Map<StringName, Vector<SignalParameter>> _signals;
	Map<StringName, EventSignal> event_signals;
	bool signals_invalidated = true;

	Vector<Multiplayer::RPCConfig> rpc_functions;

#ifdef TOOLS_ENABLED
	List<PropertyInfo> exported_members_cache; // members_cache
	Map<StringName, Variant> exported_members_defval_cache; // member_default_values_cache
	Set<PlaceHolderScriptInstance *> placeholders;
	bool source_changed_cache = false;
	bool placeholder_fallback_enabled = false;
	bool exports_invalidated = true;
	void _update_exports_values(Map<StringName, Variant> &values, List<PropertyInfo> &propnames);
	void _update_member_info_no_exports();
	void _placeholder_erased(PlaceHolderScriptInstance *p_placeholder) override;
#endif

#if defined(TOOLS_ENABLED) || defined(DEBUG_ENABLED)
	Set<StringName> exported_members_names;
#endif

	OrderedHashMap<StringName, PropertyInfo> member_info;

	void _clear();

	void _update_name();

	void load_script_signals(GDMonoClass *p_class, GDMonoClass *p_native_class);
	bool _get_signal(GDMonoClass *p_class, GDMonoMethod *p_delegate_invoke, Vector<SignalParameter> &params);

	bool _update_exports(PlaceHolderScriptInstance *p_instance_to_update = nullptr);

	bool _get_member_export(IMonoClassMember *p_member, bool p_inspect_export, PropertyInfo &r_prop_info, bool &r_exported);
#ifdef TOOLS_ENABLED
	static int _try_get_member_export_hint(IMonoClassMember *p_member, ManagedType p_type, Variant::Type p_variant_type, bool p_allow_generics, PropertyHint &r_hint, String &r_hint_string);
#endif

	CSharpInstance *_create_instance(const Variant **p_args, int p_argcount, Object *p_owner, bool p_is_ref_counted, Callable::CallError &r_error);
	Variant _new(const Variant **p_args, int p_argcount, Callable::CallError &r_error);

	// Do not use unless you know what you are doing
	friend void GDMonoInternals::tie_managed_to_unmanaged(MonoObject *, Object *);
	static Ref<CSharpScript> create_for_managed_type(GDMonoClass *p_class, GDMonoClass *p_native);
	static void update_script_class_info(Ref<CSharpScript> p_script);
	static void initialize_for_managed_type(Ref<CSharpScript> p_script, GDMonoClass *p_class, GDMonoClass *p_native);

	Multiplayer::RPCMode _member_get_rpc_mode(IMonoClassMember *p_member) const;

protected:
	static void _bind_methods();

	Variant call(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) override;
	void _resource_path_changed() override;
	bool _get(const StringName &p_name, Variant &r_ret) const;
	bool _set(const StringName &p_name, const Variant &p_value);
	void _get_property_list(List<PropertyInfo> *p_properties) const;

public:
	bool can_instantiate() const override;
	StringName get_instance_base_type() const override;
	ScriptInstance *instance_create(Object *p_this) override;
	PlaceHolderScriptInstance *placeholder_instance_create(Object *p_this) override;
	bool instance_has(const Object *p_this) const override;

	bool has_source_code() const override;
	String get_source_code() const override;
	void set_source_code(const String &p_code) override;

#ifdef TOOLS_ENABLED
	virtual const Vector<DocData::ClassDoc> &get_documentation() const override {
		// TODO
		static Vector<DocData::ClassDoc> docs;
		return docs;
	}
#endif // TOOLS_ENABLED

	Error reload(bool p_keep_state = false) override;

	bool has_script_signal(const StringName &p_signal) const override;
	void get_script_signal_list(List<MethodInfo> *r_signals) const override;

	bool get_property_default_value(const StringName &p_property, Variant &r_value) const override;
	void get_script_property_list(List<PropertyInfo> *r_list) const override;
	void update_exports() override;

	void get_members(Set<StringName> *p_members) override;

	bool is_tool() const override { return tool; }
	bool is_valid() const override { return valid; }

	bool inherits_script(const Ref<Script> &p_script) const override;

	Ref<Script> get_base_script() const override;
	ScriptLanguage *get_language() const override;

	void get_script_method_list(List<MethodInfo> *p_list) const override;
	bool has_method(const StringName &p_method) const override;
	MethodInfo get_method_info(const StringName &p_method) const override;

	int get_member_line(const StringName &p_member) const override;

	const Vector<Multiplayer::RPCConfig> get_rpc_methods() const override;

#ifdef TOOLS_ENABLED
	bool is_placeholder_fallback_enabled() const override { return placeholder_fallback_enabled; }
#endif

	Error load_source_code(const String &p_path);

	CSharpScript();
	~CSharpScript();
};

class CSharpInstance : public ScriptInstance {
	friend class CSharpScript;
	friend class CSharpLanguage;

	Object *owner = nullptr;
	bool base_ref_counted = false;
	bool ref_dying = false;
	bool unsafe_referenced = false;
	bool predelete_notified = false;
	bool destructing_script_instance = false;

	Ref<CSharpScript> script;
	MonoGCHandleData gchandle;

	List<Callable> connected_event_signals;

	bool _reference_owner_unsafe();

	/*
	 * If true is returned, the caller must memdelete the script instance's owner.
	 */
	bool _unreference_owner_unsafe();

	/*
	 * If nullptr is returned, the caller must destroy the script instance by removing it from its owner.
	 */
	MonoObject *_internal_new_managed();

	// Do not use unless you know what you are doing
	friend void GDMonoInternals::tie_managed_to_unmanaged(MonoObject *, Object *);
	static CSharpInstance *create_for_managed_type(Object *p_owner, CSharpScript *p_script, const MonoGCHandleData &p_gchandle);

	void get_properties_state_for_reloading(List<Pair<StringName, Variant>> &r_state);
	void get_event_signals_state_for_reloading(List<Pair<StringName, Array>> &r_state);

public:
	MonoObject *get_mono_object() const;

	_FORCE_INLINE_ bool is_destructing_script_instance() { return destructing_script_instance; }

	Object *get_owner() override;

	bool set(const StringName &p_name, const Variant &p_value) override;
	bool get(const StringName &p_name, Variant &r_ret) const override;
	void get_property_list(List<PropertyInfo> *p_properties) const override;
	Variant::Type get_property_type(const StringName &p_name, bool *r_is_valid) const override;

	void get_method_list(List<MethodInfo> *p_list) const override;
	bool has_method(const StringName &p_method) const override;
	Variant call(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) override;

	void mono_object_disposed(MonoObject *p_obj);

	/*
	 * If 'r_delete_owner' is set to true, the caller must memdelete the script instance's owner. Otherwise, if
	 * 'r_remove_script_instance' is set to true, the caller must destroy the script instance by removing it from its owner.
	 */
	void mono_object_disposed_baseref(MonoObject *p_obj, bool p_is_finalizer, bool &r_delete_owner, bool &r_remove_script_instance);

	void connect_event_signals();
	void disconnect_event_signals();

	void refcount_incremented() override;
	bool refcount_decremented() override;

	const Vector<Multiplayer::RPCConfig> get_rpc_methods() const override;

	void notification(int p_notification) override;
	void _call_notification(int p_notification);

	String to_string(bool *r_valid) override;

	Ref<Script> get_script() const override;

	ScriptLanguage *get_language() override;

	CSharpInstance(const Ref<CSharpScript> &p_script);
	~CSharpInstance();
};

struct CSharpScriptBinding {
	bool inited = false;
	StringName type_name;
	GDMonoClass *wrapper_class = nullptr;
	MonoGCHandleData gchandle;
	Object *owner = nullptr;

	CSharpScriptBinding() {}
};

class ManagedCallableMiddleman : public Object {
	GDCLASS(ManagedCallableMiddleman, Object);
};

class CSharpLanguage : public ScriptLanguage {
	friend class CSharpScript;
	friend class CSharpInstance;

	static CSharpLanguage *singleton;

	bool finalizing = false;
	bool finalized = false;

	GDMono *gdmono = nullptr;
	SelfList<CSharpScript>::List script_list;

	Mutex script_instances_mutex;
	Mutex script_gchandle_release_mutex;
	Mutex language_bind_mutex;

	Map<Object *, CSharpScriptBinding> script_bindings;

#ifdef DEBUG_ENABLED
	// List of unsafe object references
	Map<ObjectID, int> unsafe_object_references;
	Mutex unsafe_object_references_lock;
#endif

	ManagedCallableMiddleman *managed_callable_middleman = memnew(ManagedCallableMiddleman);

	struct StringNameCache {
		StringName _signal_callback;
		StringName _set;
		StringName _get;
		StringName _get_property_list;
		StringName _notification;
		StringName _script_source;
		StringName dotctor; // .ctor
		StringName on_before_serialize; // OnBeforeSerialize
		StringName on_after_deserialize; // OnAfterDeserialize
		StringName delegate_invoke_method_name;

		StringNameCache();
	};

	int lang_idx = -1;

	HashMap<String, DotNetScriptLookupInfo> dotnet_script_lookup_map;

	void lookup_script_for_class(GDMonoClass *p_class);

	// For debug_break and debug_break_parse
	int _debug_parse_err_line = -1;
	String _debug_parse_err_file;
	String _debug_error;

	friend class GDMono;
	void _on_scripts_domain_unloaded();

#ifdef TOOLS_ENABLED
	EditorPlugin *godotsharp_editor = nullptr;

	static void _editor_init_callback();
#endif

	static void *_instance_binding_create_callback(void *p_token, void *p_instance);
	static void _instance_binding_free_callback(void *p_token, void *p_instance, void *p_binding);
	static GDNativeBool _instance_binding_reference_callback(void *p_token, void *p_binding, GDNativeBool p_reference);

	static GDNativeInstanceBindingCallbacks _instance_binding_callbacks;

public:
	static void *get_instance_binding(Object *p_object);
	static void *get_existing_instance_binding(Object *p_object);
	static void set_instance_binding(Object *p_object, void *p_binding);
	static bool has_instance_binding(Object *p_object);

	StringNameCache string_names;

	const Mutex &get_language_bind_mutex() { return language_bind_mutex; }

	_FORCE_INLINE_ int get_language_index() { return lang_idx; }
	void set_language_index(int p_idx);

	_FORCE_INLINE_ const StringNameCache &get_string_names() { return string_names; }

	_FORCE_INLINE_ static CSharpLanguage *get_singleton() { return singleton; }

#ifdef TOOLS_ENABLED
	_FORCE_INLINE_ EditorPlugin *get_godotsharp_editor() const { return godotsharp_editor; }
#endif

	static void release_script_gchandle(MonoGCHandleData &p_gchandle);
	static void release_script_gchandle(MonoObject *p_expected_obj, MonoGCHandleData &p_gchandle);

	bool debug_break(const String &p_error, bool p_allow_continue = true);
	bool debug_break_parse(const String &p_file, int p_line, const String &p_error);

#ifdef GD_MONO_HOT_RELOAD
	bool is_assembly_reloading_needed();
	void reload_assemblies(bool p_soft_reload);
#endif

	_FORCE_INLINE_ ManagedCallableMiddleman *get_managed_callable_middleman() const { return managed_callable_middleman; }

	void lookup_scripts_in_assembly(GDMonoAssembly *p_assembly);

	const DotNetScriptLookupInfo *lookup_dotnet_script(const String &p_script_path) const {
		return dotnet_script_lookup_map.getptr(p_script_path);
	}

	String get_name() const override;

	/* LANGUAGE FUNCTIONS */
	String get_type() const override;
	String get_extension() const override;
	Error execute_file(const String &p_path) override;
	void init() override;
	void finish() override;

	void finalize();

	/* EDITOR FUNCTIONS */
	void get_reserved_words(List<String> *p_words) const override;
	bool is_control_flow_keyword(String p_keyword) const override;
	void get_comment_delimiters(List<String> *p_delimiters) const override;
	void get_string_delimiters(List<String> *p_delimiters) const override;
	Ref<Script> get_template(const String &p_class_name, const String &p_base_class_name) const override;
	bool is_using_templates() override;
	void make_template(const String &p_class_name, const String &p_base_class_name, Ref<Script> &p_script) override;
	/* TODO */ bool validate(const String &p_script, const String &p_path, List<String> *r_functions,
			List<ScriptLanguage::ScriptError> *r_errors = nullptr, List<ScriptLanguage::Warning> *r_warnings = nullptr, Set<int> *r_safe_lines = nullptr) const override {
		return true;
	}
	String validate_path(const String &p_path) const override;
	Script *create_script() const override;
	bool has_named_classes() const override;
	bool supports_builtin_mode() const override;
	/* TODO? */ int find_function(const String &p_function, const String &p_code) const override { return -1; }
	String make_function(const String &p_class, const String &p_name, const PackedStringArray &p_args) const override;
	virtual String _get_indentation() const;
	/* TODO? */ void auto_indent_code(String &p_code, int p_from_line, int p_to_line) const override {}
	/* TODO */ void add_global_constant(const StringName &p_variable, const Variant &p_value) override {}

	/* DEBUGGER FUNCTIONS */
	String debug_get_error() const override;
	int debug_get_stack_level_count() const override;
	int debug_get_stack_level_line(int p_level) const override;
	String debug_get_stack_level_function(int p_level) const override;
	String debug_get_stack_level_source(int p_level) const override;
	/* TODO */ void debug_get_stack_level_locals(int p_level, List<String> *p_locals, List<Variant> *p_values, int p_max_subitems, int p_max_depth) override {}
	/* TODO */ void debug_get_stack_level_members(int p_level, List<String> *p_members, List<Variant> *p_values, int p_max_subitems, int p_max_depth) override {}
	/* TODO */ void debug_get_globals(List<String> *p_locals, List<Variant> *p_values, int p_max_subitems, int p_max_depth) override {}
	/* TODO */ String debug_parse_stack_level_expression(int p_level, const String &p_expression, int p_max_subitems, int p_max_depth) override { return ""; }
	Vector<StackInfo> debug_get_current_stack_info() override;

	/* PROFILING FUNCTIONS */
	/* TODO */ void profiling_start() override {}
	/* TODO */ void profiling_stop() override {}
	/* TODO */ int profiling_get_accumulated_data(ProfilingInfo *p_info_arr, int p_info_max) override { return 0; }
	/* TODO */ int profiling_get_frame_data(ProfilingInfo *p_info_arr, int p_info_max) override { return 0; }

	void frame() override;

	/* TODO? */ void get_public_functions(List<MethodInfo> *p_functions) const override {}
	/* TODO? */ void get_public_constants(List<Pair<String, Variant>> *p_constants) const override {}

	void reload_all_scripts() override;
	void reload_tool_script(const Ref<Script> &p_script, bool p_soft_reload) override;

	/* LOADER FUNCTIONS */
	void get_recognized_extensions(List<String> *p_extensions) const override;

#ifdef TOOLS_ENABLED
	Error open_in_external_editor(const Ref<Script> &p_script, int p_line, int p_col) override;
	bool overrides_external_editor() override;
#endif

	/* THREAD ATTACHING */
	void thread_enter() override;
	void thread_exit() override;

	Map<Object *, CSharpScriptBinding>::Element *insert_script_binding(Object *p_object, const CSharpScriptBinding &p_script_binding);
	bool setup_csharp_script_binding(CSharpScriptBinding &r_script_binding, Object *p_object);

#ifdef DEBUG_ENABLED
	Vector<StackInfo> stack_trace_get_info(MonoObject *p_stack_trace);
#endif

	void post_unsafe_reference(Object *p_obj);
	void pre_unsafe_unreference(Object *p_obj);

	CSharpLanguage();
	~CSharpLanguage();
};

class ResourceFormatLoaderCSharpScript : public ResourceFormatLoader {
public:
	RES load(const String &p_path, const String &p_original_path = "", Error *r_error = nullptr, bool p_use_sub_threads = false, float *r_progress = nullptr, CacheMode p_cache_mode = CACHE_MODE_REUSE) override;
	void get_recognized_extensions(List<String> *p_extensions) const override;
	bool handles_type(const String &p_type) const override;
	String get_resource_type(const String &p_path) const override;
};

class ResourceFormatSaverCSharpScript : public ResourceFormatSaver {
public:
	Error save(const String &p_path, const RES &p_resource, uint32_t p_flags = 0) override;
	void get_recognized_extensions(const RES &p_resource, List<String> *p_extensions) const override;
	bool recognize(const RES &p_resource) const override;
};

#endif // CSHARP_SCRIPT_H