/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; -*- */
// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
// SPDX-FileCopyrightText: 2008 litl, LLC

#pragma once

#include <config.h>

#include <stddef.h>  // for size_t
#include <stdint.h>  // for uint32_t

#include <functional>
#include <unordered_set>
#include <vector>

#include <girepository/girepository.h>
#include <glib-object.h>
#include <glib.h>

#include <js/AllocPolicy.h>
#include <js/GCHashTable.h>  // for GCHashMap
#include <js/HashTable.h>    // for DefaultHasher
#include <js/Id.h>
#include <js/RootingAPI.h>
#include <js/TypeDecls.h>
#include <mozilla/HashFunctions.h>  // for HashGeneric, HashNumber
#include <mozilla/Likely.h>         // for MOZ_LIKELY
#include <mozilla/Maybe.h>

#include "gi/info.h"
#include "gi/value.h"
#include "gi/wrapperutils.h"
#include "gjs/auto.h"
#include "gjs/jsapi-util-root.h"
#include "gjs/jsapi-util.h"  // for gjs_throw
#include "gjs/macros.h"
#include "util/log.h"

class GjsAtoms;
struct JSFunctionSpec;
struct JSPropertySpec;
class JSTracer;
namespace JS {
class CallArgs;
}
namespace Gjs::Test {
struct ObjectInstance;
}
class ObjectInstance;
class ObjectPrototype;
class ObjectPropertyInfoCaller;
class ObjectPropertyPspecCaller;

/**
 * ObjectBase:
 *
 * Specialization of GIWrapperBase for GObject instances. See the documentation
 * in wrapperutils.h.
 *
 * It's important that ObjectBase and ObjectInstance not grow in size without a
 * very good reason. There can be tens, maybe hundreds of thousands of these
 * objects alive in a typical gnome-shell run, so even 8 more bytes will add up.
 * It's less critical that ObjectPrototype stay small, since only one of these
 * is allocated per GType.
 */
class ObjectBase
    : public GIWrapperBase<ObjectBase, ObjectPrototype, ObjectInstance> {
    friend class GIWrapperBase<ObjectBase, ObjectPrototype, ObjectInstance>;

 protected:
    explicit ObjectBase(ObjectPrototype* proto = nullptr)
        : GIWrapperBase(proto) {}

 public:
    using SignalMatchFunc = unsigned(void*, GSignalMatchType, unsigned, GQuark,
                                     GClosure*, void*, void*);
    static constexpr GjsDebugTopic DEBUG_TOPIC = GJS_DEBUG_GOBJECT;
    static constexpr const char* DEBUG_TAG = "GObject";

    static const struct JSClassOps class_ops;
    static const struct JSClass klass;
    static JSFunctionSpec proto_methods[];
    static JSPropertySpec proto_properties[];

    static GObject* to_c_ptr(JSContext*, JS::HandleObject) = delete;
    GJS_JSAPI_RETURN_CONVENTION
    static bool to_c_ptr(JSContext*, JS::HandleObject, GObject** ptr);
    GJS_JSAPI_RETURN_CONVENTION
    static bool transfer_to_gi_argument(JSContext*, JS::HandleObject,
                                        GIArgument*,
                                        GIDirection transfer_direction,
                                        GITransfer transfer_ownership,
                                        GType expected_gtype);

 private:
    // This is used in debug methods only.
    [[nodiscard]] const void* jsobj_addr() const;

    // Helper methods

 protected:
    void debug_lifecycle(const char* message) const {
        GIWrapperBase::debug_lifecycle(jsobj_addr(), message);
    }

    [[nodiscard]] static bool id_is_never_lazy(jsid name, const GjsAtoms&);
    [[nodiscard]] bool is_custom_js_class();

 public:
    // Overrides GIWrapperBase::typecheck(). We only override the overload that
    // throws, so that we can throw our own more informative error.
    template <typename T>
    GJS_JSAPI_RETURN_CONVENTION
    static bool typecheck(JSContext* cx, JS::HandleObject obj, T expected) {
        if (GIWrapperBase::typecheck(cx, obj, expected))
            return true;

        gjs_throw(cx,
                  "This JS object wrapper isn't wrapping a GObject."
                  " If this is a custom subclass, are you sure you chained"
                  " up to the parent _init properly?");
        return false;
    }
    template <typename T>
    [[nodiscard]]
    static bool typecheck(JSContext* cx, JS::HandleObject obj, T expected,
                          GjsTypecheckNoThrow no_throw) {
        return GIWrapperBase::typecheck(cx, obj, expected, no_throw);
    }

    // JSClass operations

    static bool add_property(JSContext*, JS::HandleObject, JS::HandleId,
                             JS::HandleValue);

    // JS property getters/setters

    template <typename TAG = void>
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_getter(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_getter_write_only(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_getter_func(JSContext*, unsigned, JS::Value*);
    template <typename TAG, GITransfer TRANSFER = GI_TRANSFER_NOTHING>
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_getter_simple_type_func(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool field_getter(JSContext*, unsigned, JS::Value*);
    template <typename TAG = void>
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_setter(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_setter_read_only(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_setter_func(JSContext*, unsigned, JS::Value*);
    template <typename TAG, GITransfer TRANSFER = GI_TRANSFER_NOTHING>
    GJS_JSAPI_RETURN_CONVENTION
    static bool prop_setter_simple_type_func(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool field_setter(JSContext*, unsigned, JS::Value*);

    // JS methods

    GJS_JSAPI_RETURN_CONVENTION
    static bool connect(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool connect_after(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool connect_object(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool emit(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool signal_find(JSContext*, unsigned, JS::Value*);
    template <SignalMatchFunc(*MATCH_FUNC)>
    GJS_JSAPI_RETURN_CONVENTION
    static bool signals_action(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool to_string(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool init_gobject(JSContext*, unsigned, JS::Value*);
    GJS_JSAPI_RETURN_CONVENTION
    static bool hook_up_vfunc(JSContext*, unsigned, JS::Value*);

    // Quarks

 protected:
    [[nodiscard]] static GQuark instance_strings_quark();

 public:
    [[nodiscard]] static GQuark custom_type_quark();
    [[nodiscard]] static GQuark custom_property_quark();
    [[nodiscard]] static GQuark disposed_quark();
};

// See https://bugzilla.mozilla.org/show_bug.cgi?id=1614220
struct IdHasher {
    using Lookup = jsid;
    static mozilla::HashNumber hash(jsid id) {
        if (MOZ_LIKELY(id.isString()))
            return js::DefaultHasher<JSString*>::hash(id.toString());
        if (id.isSymbol())
            return js::DefaultHasher<JS::Symbol*>::hash(id.toSymbol());
        return mozilla::HashGeneric(id.asRawBits());
    }
    static bool match(jsid id1, jsid id2) { return id1 == id2; }
};

class ObjectPrototype
    : public GIWrapperPrototype<ObjectBase, ObjectPrototype, ObjectInstance,
                                mozilla::Maybe<GI::AutoObjectInfo>,
                                mozilla::Maybe<GI::ObjectInfo>> {
    friend class GIWrapperPrototype<ObjectBase, ObjectPrototype, ObjectInstance,
                                    mozilla::Maybe<GI::AutoObjectInfo>,
                                    mozilla::Maybe<GI::ObjectInfo>>;
    friend class GIWrapperBase<ObjectBase, ObjectPrototype, ObjectInstance>;

    using NegativeLookupCache =
        JS::GCHashSet<JS::Heap<jsid>, IdHasher, js::SystemAllocPolicy>;

    NegativeLookupCache m_unresolvable_cache;
    // a list of vfunc GClosures installed on this prototype, used when tracing
    std::unordered_set<GClosure*> m_vfuncs;
    // a list of interface types explicitly associated with this prototype,
    // by gjs_add_interface
    std::vector<GType> m_interface_gtypes;

    ObjectPrototype(const mozilla::Maybe<GI::ObjectInfo>&, GType);
    ~ObjectPrototype();

 public:
    [[nodiscard]] static ObjectPrototype* for_gtype(GType);

    // Helper methods
 private:
    GJS_JSAPI_RETURN_CONVENTION
    bool get_parent_proto(JSContext*, JS::MutableHandleObject proto) const;
    GJS_JSAPI_RETURN_CONVENTION
    bool get_parent_constructor(JSContext*,
                                JS::MutableHandleObject constructor) const;
    [[nodiscard]] bool is_vfunc_unchanged(const GI::VFuncInfo&) const;
    static void vfunc_invalidated_notify(void* data, GClosure*);

    GJS_JSAPI_RETURN_CONVENTION
    bool lazy_define_gobject_property(
        JSContext*, JS::HandleObject, JS::HandleId, GParamSpec*, bool* resolved,
        const char* name,
        const mozilla::Maybe<const GI::AutoPropertyInfo>& = {});

    enum ResolveWhat : uint8_t {
        ConsiderOnlyMethods,
        ConsiderMethodsAndProperties
    };
    GJS_JSAPI_RETURN_CONVENTION
    bool resolve_no_info(JSContext*, JS::HandleObject, JS::HandleId,
                         bool* resolved, const char* name, ResolveWhat);
    GJS_JSAPI_RETURN_CONVENTION
    bool uncached_resolve(JSContext*, JS::HandleObject, JS::HandleId,
                          const char* name, bool* resolved);

 public:
    void set_interfaces(GType* interface_gtypes, uint32_t n_interface_gtypes);
    void set_type_qdata();
    GJS_JSAPI_RETURN_CONVENTION
    GParamSpec* find_param_spec_from_id(JSContext*,
                                        Gjs::AutoTypeClass<GObjectClass> const&,
                                        JS::HandleString key);
    GJS_JSAPI_RETURN_CONVENTION
    bool props_to_g_parameters(JSContext*,
                               Gjs::AutoTypeClass<GObjectClass> const&,
                               JS::HandleObject props,
                               std::vector<const char*>* names,
                               AutoGValueVector* values);

    GJS_JSAPI_RETURN_CONVENTION
    static bool define_class(JSContext*, JS::HandleObject in_object,
                             const mozilla::Maybe<const GI::ObjectInfo>&, GType,
                             GType* interface_gtypes,
                             uint32_t n_interface_gtypes,
                             JS::MutableHandleObject constructor,
                             JS::MutableHandleObject prototype);

    void ref_vfuncs() {
        for (GClosure* closure : m_vfuncs)
            g_closure_ref(closure);
    }
    void unref_vfuncs() {
        for (GClosure* closure : m_vfuncs)
            g_closure_unref(closure);
    }

    // JSClass operations
 private:
    GJS_JSAPI_RETURN_CONVENTION
    bool resolve_impl(JSContext*, JS::HandleObject, JS::HandleId,
                      bool* resolved);

    GJS_JSAPI_RETURN_CONVENTION
    bool new_enumerate_impl(JSContext*, JS::HandleObject,
                            JS::MutableHandleIdVector properties,
                            bool only_enumerable);
    void trace_impl(JSTracer*);

    // JS methods
 public:
    GJS_JSAPI_RETURN_CONVENTION
    bool hook_up_vfunc_impl(JSContext*, const JS::CallArgs&);
};

class ObjectInstance : public GIWrapperInstance<ObjectBase, ObjectPrototype,
                                                ObjectInstance, GObject> {
    friend class GIWrapperInstance<ObjectBase, ObjectPrototype, ObjectInstance,
                                   GObject>;
    friend class GIWrapperBase<ObjectBase, ObjectPrototype, ObjectInstance>;
    friend class ObjectBase;  // for add_property, prop_getter, etc.
    friend struct Gjs::Test::ObjectInstance;

    // GIWrapperInstance::m_ptr may be null in ObjectInstance.

    GjsMaybeOwned m_wrapper;
    // a list of all GClosures installed on this object (from signal connections
    // and scope-notify callbacks passed to methods), used when tracing
    std::vector<GClosure*> m_closures;

    bool m_wrapper_finalized : 1;
    bool m_gobj_disposed : 1;
    bool m_gobj_finalized : 1;

    /* True if this object has visible JS state, and thus its lifecycle is
     * managed using toggle references. False if this object just keeps a hard
     * ref on the underlying GObject, and may be finalized at will. */
    bool m_uses_toggle_ref : 1;

    static bool s_weak_pointer_callback;

    // Constructors

 private:
    ObjectInstance(ObjectPrototype*, JS::HandleObject);
    ~ObjectInstance();

    GJS_JSAPI_RETURN_CONVENTION
    static ObjectInstance* new_for_gobject(JSContext*, GObject*);

    // Extra method to get an existing ObjectInstance from qdata

 public:
    [[nodiscard]] static ObjectInstance* for_gobject(GObject*);

    // Accessors

 private:
    [[nodiscard]] bool has_wrapper() const { return !!m_wrapper; }

 public:
    [[nodiscard]] JSObject* wrapper() const { return m_wrapper.get(); }

    // Methods to manipulate the JS object wrapper

 private:
    void discard_wrapper() { m_wrapper.reset(); }
    void switch_to_rooted(JSContext* cx) { m_wrapper.switch_to_rooted(cx); }
    void switch_to_unrooted(JSContext* cx) { m_wrapper.switch_to_unrooted(cx); }
    [[nodiscard]]
    bool update_after_gc(JSTracer* trc) {
        return m_wrapper.update_after_gc(trc);
    }
    [[nodiscard]] bool wrapper_is_rooted() const { return m_wrapper.rooted(); }
    void release_native_object();
    void associate_js_gobject(JSContext*, JS::HandleObject, GObject*);
    void disassociate_js_gobject();
    void handle_context_dispose();
    [[nodiscard]] bool weak_pointer_was_finalized(JSTracer*);
    static void ensure_weak_pointer_callback(JSContext*);
    static void update_heap_wrapper_weak_pointers(JSTracer*, JS::Compartment*,
                                                  void* data);

 public:
    void toggle_down();
    void toggle_up();

    GJS_JSAPI_RETURN_CONVENTION
    static JSObject* wrapper_from_gobject(JSContext*, GObject*);

    GJS_JSAPI_RETURN_CONVENTION
    static bool set_value_from_gobject(JSContext*, GObject*,
                                       JS::MutableHandleValue);

    // Methods to manipulate the list of closures

 private:
    void invalidate_closures();
    static void closure_invalidated_notify(void* data, GClosure*);

 public:
    void associate_closure(JSContext*, GClosure*);

    // Helper methods

 private:
    void set_object_qdata();
    void unset_object_qdata();
    void track_gobject_finalization();
    void ignore_gobject_finalization();
    void check_js_object_finalized();
    void ensure_uses_toggle_ref(JSContext*);
    [[nodiscard]]
    bool check_gobject_disposed_or_finalized(const char* for_what) const;
    [[nodiscard]] bool check_gobject_finalized(const char* for_what) const;
    GJS_JSAPI_RETURN_CONVENTION
    bool signal_match_arguments_from_object(
        JSContext*, JS::HandleObject match_obj, GSignalMatchType* mask_out,
        unsigned* signal_id_out, GQuark* detail_out,
        JS::MutableHandleObject callable_out);

 public:
    static GObject* copy_ptr(JSContext*, GType, void* ptr) {
        return G_OBJECT(g_object_ref(G_OBJECT(ptr)));
    }

    GJS_JSAPI_RETURN_CONVENTION
    bool init_custom_class_from_gobject(JSContext*, JS::HandleObject wrapper,
                                        GObject*);

    static void associate_string(GObject*, char* str);

    // Methods to manipulate the linked list of instances

 private:
    static std::unordered_set<ObjectInstance*> s_wrapped_gobject_list;
    void link();
    void unlink();
    [[nodiscard]]
    static size_t num_wrapped_gobjects() {
        return s_wrapped_gobject_list.size();
    }
    using Action = std::function<void(ObjectInstance*)>;
    using Predicate = std::function<bool(ObjectInstance*)>;
    static void remove_wrapped_gobjects_if(const Predicate&, const Action&);

 public:
    static void prepare_shutdown();

    // JSClass operations

 private:
    GJS_JSAPI_RETURN_CONVENTION
    bool add_property_impl(JSContext*, JS::HandleObject, JS::HandleId,
                           JS::HandleValue);
    void finalize_impl(JS::GCContext*, JSObject*);
    void trace_impl(JSTracer*);

    // JS property getters/setters

    template <typename TAG>
    GJS_JSAPI_RETURN_CONVENTION
    bool prop_getter_impl(JSContext*, GParamSpec*, JS::MutableHandleValue rval);
    GJS_JSAPI_RETURN_CONVENTION
    bool prop_getter_impl(JSContext*, ObjectPropertyInfoCaller*,
                          JS::CallArgs const&);
    template <typename TAG, GITransfer TRANSFER = GI_TRANSFER_NOTHING>
    GJS_JSAPI_RETURN_CONVENTION
    bool prop_getter_impl(JSContext*, ObjectPropertyPspecCaller*,
                          JS::CallArgs const&);
    GJS_JSAPI_RETURN_CONVENTION
    bool field_getter_impl(JSContext*, GI::AutoFieldInfo const&,
                           JS::MutableHandleValue rval);
    template <typename TAG>
    GJS_JSAPI_RETURN_CONVENTION
    bool prop_setter_impl(JSContext*, GParamSpec*, JS::HandleValue);
    GJS_JSAPI_RETURN_CONVENTION
    bool prop_setter_impl(JSContext*, ObjectPropertyInfoCaller*,
                          JS::CallArgs const&);
    template <typename TAG, GITransfer TRANSFER = GI_TRANSFER_NOTHING>
    GJS_JSAPI_RETURN_CONVENTION
    bool prop_setter_impl(JSContext*, ObjectPropertyPspecCaller*,
                          JS::CallArgs const&);
    GJS_JSAPI_RETURN_CONVENTION
    bool field_setter_not_impl(JSContext*, GI::AutoFieldInfo const&);

    // JS constructor

    GJS_JSAPI_RETURN_CONVENTION
    static bool constructor_impl(JSContext*, JS::HandleObject,
                                 const JS::CallArgs&);

    // JS methods

    GJS_JSAPI_RETURN_CONVENTION
    bool connect_impl(JSContext*, const JS::CallArgs&, bool after,
                      bool object = false);
    GJS_JSAPI_RETURN_CONVENTION
    bool emit_impl(JSContext*, const JS::CallArgs&);
    GJS_JSAPI_RETURN_CONVENTION
    bool signal_find_impl(JSContext*, const JS::CallArgs&);
    template <SignalMatchFunc(*MATCH_FUNC)>
    GJS_JSAPI_RETURN_CONVENTION
    bool signals_action_impl(JSContext*, const JS::CallArgs&);
    GJS_JSAPI_RETURN_CONVENTION
    bool init_impl(JSContext*, const JS::CallArgs&, JS::HandleObject);
    [[nodiscard]] const char* to_string_kind() const;

    // Overrides GIWrapperInstance::typecheck_impl()
    template <typename T>
    GJS_JSAPI_RETURN_CONVENTION
    bool typecheck_impl(T expected) const {
        g_assert(m_gobj_disposed || !m_ptr ||
                 g_type_is_a(gtype(), G_OBJECT_TYPE(m_ptr.as<GObject*>())));
        return GIWrapperInstance::typecheck_impl(expected);
    }

    // Notification callbacks
    void gobj_dispose_notify();
    static void wrapped_gobj_dispose_notify(void* data, GObject*);
    static void wrapped_gobj_toggle_notify(void* instance, GObject*,
                                           gboolean is_last_ref);

 public:
    static void context_dispose_notify(void* data,
                                       GObject* where_the_object_was);
};

GJS_JSAPI_RETURN_CONVENTION
bool gjs_lookup_object_constructor(JSContext*, GType, JS::MutableHandleValue);

void gjs_object_clear_toggles();
void gjs_object_shutdown_toggle_queue();
