/*

    tests/test_call_policies.cpp -- keep_alive and call_guard

    Copyright (c) 2016 Wenzel Jakob <wenzel.jakob@epfl.ch>

    All rights reserved. Use of this source code is governed by a

    BSD-style license that can be found in the LICENSE file.

*/

#include "pybind11_tests.h"

struct CustomGuard {

    static bool enabled;

    CustomGuard() { enabled = true; }

    ~CustomGuard() { enabled = false; }

    static const char *report_status() { return enabled ? "guarded" : "unguarded"; }

};

bool CustomGuard::enabled = false;

struct DependentGuard {

    static bool enabled;

    DependentGuard() { enabled = CustomGuard::enabled; }

    ~DependentGuard() { enabled = false; }

    static const char *report_status() { return enabled ? "guarded" : "unguarded"; }

};

bool DependentGuard::enabled = false;

TEST_SUBMODULE(call_policies, m) {

    // Parent/Child are used in:

    // test_keep_alive_argument, test_keep_alive_return_value, test_alive_gc_derived,

    // test_alive_gc_multi_derived, test_return_none, test_keep_alive_constructor

    class Child {

    public:

        Child() { py::print("Allocating child."); }

        Child(const Child &) = default;

        Child(Child &&) = default;

        ~Child() { py::print("Releasing child."); }

    };

    py::class_<Child>(m, "Child")

        .def(py::init<>());

    class Parent {

    public:

        Parent() { py::print("Allocating parent."); }

        ~Parent() { py::print("Releasing parent."); }

        void addChild(Child *) { }

        Child *returnChild() { return new Child(); }

        Child *returnNullChild() { return nullptr; }

    };

    py::class_<Parent>(m, "Parent")

        .def(py::init<>())

        .def(py::init([](Child *) { return new Parent(); }), py::keep_alive<1, 2>())

        .def("addChild", &Parent::addChild)

        .def("addChildKeepAlive", &Parent::addChild, py::keep_alive<1, 2>())

        .def("returnChild", &Parent::returnChild)

        .def("returnChildKeepAlive", &Parent::returnChild, py::keep_alive<1, 0>())

        .def("returnNullChildKeepAliveChild", &Parent::returnNullChild, py::keep_alive<1, 0>())

        .def("returnNullChildKeepAliveParent", &Parent::returnNullChild, py::keep_alive<0, 1>());

#if !defined(PYPY_VERSION)

    // test_alive_gc

    class ParentGC : public Parent {

    public:

        using Parent::Parent;

    };

    py::class_<ParentGC, Parent>(m, "ParentGC", py::dynamic_attr())

        .def(py::init<>());

#endif

    // test_call_guard

    m.def("unguarded_call", &CustomGuard::report_status);

    m.def("guarded_call", &CustomGuard::report_status, py::call_guard<CustomGuard>());

    m.def("multiple_guards_correct_order", []() {

        return CustomGuard::report_status() + std::string(" & ") + DependentGuard::report_status();

    }, py::call_guard<CustomGuard, DependentGuard>());

    m.def("multiple_guards_wrong_order", []() {

        return DependentGuard::report_status() + std::string(" & ") + CustomGuard::report_status();

    }, py::call_guard<DependentGuard, CustomGuard>());

#if defined(WITH_THREAD) && !defined(PYPY_VERSION)

    // `py::call_guard<py::gil_scoped_release>()` should work in PyPy as well,

    // but it's unclear how to test it without `PyGILState_GetThisThreadState`.

    auto report_gil_status = []() {

        auto is_gil_held = false;

        if (auto tstate = py::detail::get_thread_state_unchecked())

            is_gil_held = (tstate == PyGILState_GetThisThreadState());

        return is_gil_held ? "GIL held" : "GIL released";

    };

    m.def("with_gil", report_gil_status);

    m.def("without_gil", report_gil_status, py::call_guard<py::gil_scoped_release>());

#endif

}