OrcaSlicer_orcaslicer/src/slic3r/plugin/PythonPluginBridge.cpp

#include "PythonPluginBridge.hpp"

#include <boost/log/trivial.hpp>
#include <exception>
#include <memory>
#include <mutex>
#include <slic3r/plugin/PluginAuditManager.hpp>
#include <string>
#include <unordered_map>

#include <pybind11/embed.h>
#include <pybind11/pybind11.h>
#include <pybind11/stl.h>

#include "PythonInterpreter.hpp"
#include "PluginFsUtils.hpp"
#include "PluginConfig.hpp"
#include "host/PluginHost.hpp"
#include "PyPluginPackage.hpp"
#include "PyPluginTrampoline.hpp"
#include "pluginTypes/printerAgent/PrinterAgentPluginCapability.hpp"
#include "pluginTypes/script/ScriptPluginCapability.hpp"
#include "pluginTypes/slicingPipeline/SlicingPipelinePluginCapability.hpp"

namespace py = pybind11;

namespace Slic3r {
namespace {

// Python plugin discovery is a two-step capture:
// 1) PluginLoader sets an active plugin key and imports the Python module.
// 2) Python decorators/API calls enter these pybind callbacks without receiving the
//    C++ PluginDescriptor, so the callbacks use the active key to attach Python classes
//    to the plugin currently being loaded.
//
// The pending maps hold Python class objects, not plugin instances. Instances are created
// only after the package class has had a chance to register every capability.
thread_local std::string g_active_plugin_key;
std::mutex g_registry_mutex;
std::unordered_map<std::string, std::vector<py::object>> g_pending_capabilities;
std::unordered_map<std::string, py::object> g_pending_package;
struct PluginInstanceHandle
{
    // The C++ plugin interface points into a Python object. Keep both alive through one
    // shared control block; CapturedCapability later exposes an aliasing shared_ptr to plugin.
    std::shared_ptr<PluginCapabilityInterface> plugin;
    py::object keep_alive;

    ~PluginInstanceHandle()
    {
        if (keep_alive) {
            // Dropping a py::object decrefs the Python object, so acquire a runtime lease and
            // the GIL. If shutdown has already won the lease, intentionally abandon the wrapper.
            PythonGILState gil;
            if (gil) {
                keep_alive = py::object();
            } else {
                (void) keep_alive.release();
            }
        }
    }
};

void discard_pending_capture_without_python(const std::string& plugin_key)
{
    std::lock_guard<std::mutex> lock(g_registry_mutex);
    auto                        capabilities = g_pending_capabilities.find(plugin_key);
    if (capabilities != g_pending_capabilities.end()) {
        for (py::object& capability : capabilities->second)
            (void) capability.release();
        g_pending_capabilities.erase(capabilities);
    }

    auto package = g_pending_package.find(plugin_key);
    if (package != g_pending_package.end()) {
        (void) package->second.release();
        g_pending_package.erase(package);
    }
}

} // namespace

PythonPluginBridge& PythonPluginBridge::instance()
{
    static PythonPluginBridge bridge;
    return bridge;
}

void PythonPluginBridge::begin_plugin_capture(const std::string& plugin_key)
{
    PythonGILState gil;
    if (!gil) {
        BOOST_LOG_TRIVIAL(warning) << "Cannot begin Python plugin capture while the interpreter is shutting down";
        return;
    }
    BOOST_LOG_TRIVIAL(info) << "Beginning Python plugin capture for key " << plugin_key;
    {
        std::lock_guard<std::mutex> lock(g_registry_mutex);
        // Start from a clean slot in case a previous failed load left pending Python classes
        // for this same entry path.
        g_pending_capabilities.erase(plugin_key);
        g_pending_package.erase(plugin_key);
    }
    // From now until finalize/cancel, @orca.plugin and register_capability() calls made by
    // Python code on this thread are attributed to this plugin.
    g_active_plugin_key = plugin_key;
}

std::vector<CapturedCapability> PythonPluginBridge::finalize_plugin_capture(const std::string& plugin_key, std::string& error)
{
    PythonGILState gil;
    if (!gil) {
        error = "Python interpreter is shutting down";
        return {};
    }
    BOOST_LOG_TRIVIAL(info) << "Finalizing Python plugin capture for key " << plugin_key;

    // Phase 1: run the package class's register_capabilities() while the active key is
    // still set. That method is expected to call orca.register_capability() once per
    // capability class, and register_capability() needs g_active_plugin_key to know which
    // pending bucket to append to.
    {
        auto clear_active_key = [&plugin_key]() {
            if (g_active_plugin_key == plugin_key)
                g_active_plugin_key.clear();
        };
        auto discard_pending_for_key = [&plugin_key]() {
            std::lock_guard<std::mutex> lock(g_registry_mutex);
            g_pending_capabilities.erase(plugin_key);
            g_pending_package.erase(plugin_key);
        };

        try {
            // The @orca.plugin decorator records the package class during module import.
            // Move it into a local py::object and remove it from the pending map so the
            // registry no longer owns it once finalization starts.
            py::object package_cls;
            {
                std::lock_guard<std::mutex> lock(g_registry_mutex);
                auto it = g_pending_package.find(plugin_key);
                if (it != g_pending_package.end()) {
                    package_cls = it->second;
                    g_pending_package.erase(it);
                }
            }
            if (!package_cls) {
                error = "Plugin did not register a package class; decorate it with @orca.plugin";
                BOOST_LOG_TRIVIAL(error) << error << " for key " << plugin_key;
                discard_pending_for_key();
                clear_active_key();
                return {};
            }

            // The package instance is only a registration coordinator. It is not returned
            // to the rest of the plugin system; only the capability classes it registers
            // are kept.
            py::object package = package_cls();
            package.attr("register_capabilities")();
        } catch (py::error_already_set& err) {
            log_python_exception_keep(err);
            error = err.what();
            BOOST_LOG_TRIVIAL(error) << "Plugin register_capabilities raised Python exception for key " << plugin_key
                                     << " error=" << error;
            discard_pending_for_key();
            clear_active_key();
            return {};
        } catch (const std::exception& ex) {
            error = ex.what();
            BOOST_LOG_TRIVIAL(error) << "Plugin register_capabilities raised exception for key " << plugin_key
                                     << " error=" << error;
            discard_pending_for_key();
            clear_active_key();
            return {};
        }
    }

    // Phase 2: move the capability classes that register_capabilities() appended into a
    // local vector. From this point the pending registry no longer owns these py::objects.
    std::vector<py::object> classes;
    {
        std::lock_guard<std::mutex> lock(g_registry_mutex);
        auto it = g_pending_capabilities.find(plugin_key);
        if (it != g_pending_capabilities.end()) {
            classes = std::move(it->second);
            g_pending_capabilities.erase(it);
        }
    }

    // Registration is complete. Later register_capability() calls should fail instead of
    // accidentally attaching themselves to this plugin.
    if (g_active_plugin_key == plugin_key)
        g_active_plugin_key.clear();

    BOOST_LOG_TRIVIAL(info) << "Collected " << classes.size() << " registered capability class(es) for key " << plugin_key;

    std::vector<CapturedCapability> capabilities;
    capabilities.reserve(classes.size());

    // Phase 3: instantiate each registered capability class and convert it to the common
    // C++ interface used by the rest of OrcaSlicer.
    for (auto& cls : classes) {
        try {
            py::object instance = cls();
            if (!py::isinstance<PluginCapabilityInterface>(instance)) {
                error = "Registered capability must inherit from a PluginCapability base";
                BOOST_LOG_TRIVIAL(error) << "Python plugin capture failed type check for key " << plugin_key
                                         << " error=" << error;
                return {};
            }

            auto capability_iface = instance.cast<std::shared_ptr<PluginCapabilityInterface>>();
            if (!capability_iface) {
                error = "Failed to cast Python capability to PluginCapabilityInterface";
                BOOST_LOG_TRIVIAL(error) << "Python plugin capture failed cast for key " << plugin_key
                                         << " error=" << error;
                return {};
            }

            // This is a registered capability, not the transient orca.base package.
            // get_name() is required on capabilities and is cached for preset lookup.
            std::string name = capability_iface->get_name();

            // Capability names feed ';'-delimited config/preset serialization and drive
            // dispatch, so unlike display names they cannot be silently rewritten — a ';'
            // here is a hard error that rejects the whole plugin capture.
            if (name.find(';') != std::string::npos) {
                error = "Capability name must not contain ';': " + name;
                BOOST_LOG_TRIVIAL(error) << "Python plugin capture rejected capability for key " << plugin_key
                                         << " error=" << error;
                return {};
            }

            auto handle        = std::make_shared<PluginInstanceHandle>();
            handle->keep_alive = instance;
            handle->plugin     = std::move(capability_iface);

            CapturedCapability captured;
            // Return a shared_ptr<PluginCapabilityInterface> while keeping PluginInstanceHandle
            // as the owner, so the Python instance stays alive as long as the C++ interface does.
            captured.instance = std::shared_ptr<PluginCapabilityInterface>(handle, handle->plugin.get());
            captured.name     = std::move(name);
            capabilities.emplace_back(std::move(captured));
        } catch (py::error_already_set& err) {
            // Direct Python call (cls() / get_name() above), not a trampoline override —
            // log the traceback here. GIL is held for the duration of finalize_plugin_capture.
            log_python_exception_keep(err);
            error = err.what();
            BOOST_LOG_TRIVIAL(error) << "Python plugin capture raised Python exception for key " << plugin_key
                                     << " error=" << error;
            return {};
        } catch (const std::exception& ex) {
            error = ex.what();
            BOOST_LOG_TRIVIAL(error) << "Python plugin capture raised exception for key " << plugin_key
                                     << " error=" << error;
            return {};
        }
    }

    BOOST_LOG_TRIVIAL(info) << "Instantiated " << capabilities.size() << " Python capability instance(s) for key " << plugin_key;
    return capabilities;
}

void PythonPluginBridge::cancel_plugin_capture(const std::string& plugin_key)
{
    PythonGILState gil;
    BOOST_LOG_TRIVIAL(warning) << "Cancelling Python plugin capture for key " << plugin_key;

    if (!gil) {
        discard_pending_capture_without_python(plugin_key);
        if (g_active_plugin_key == plugin_key)
            g_active_plugin_key.clear();
        return;
    }

    {
        std::lock_guard<std::mutex> lock(g_registry_mutex);
        // Import or dependency setup failed before finalization. Drop anything the module
        // may already have registered under this key.
        g_pending_capabilities.erase(plugin_key);
        g_pending_package.erase(plugin_key);
    }

    if (g_active_plugin_key == plugin_key)
        g_active_plugin_key.clear();
}

void PythonPluginBridge::clear_pending_captures()
{
    PythonGILState gil;
    if (!gil) {
        std::lock_guard<std::mutex> lock(g_registry_mutex);
        BOOST_LOG_TRIVIAL(info) << "Clearing " << g_pending_capabilities.size()
                                << " pending Python plugin capture(s) without Python interpreter";
        // py::object destruction would decref Python objects. If the interpreter is already
        // gone, release the wrappers instead and intentionally skip decref.
        for (auto& [plugin_key, plugins] : g_pending_capabilities) {
            (void) plugin_key;
            for (py::object& plugin : plugins)
                (void) plugin.release();
        }
        g_pending_capabilities.clear();
        for (auto& [plugin_key, pkg] : g_pending_package) {
            (void) plugin_key;
            (void) pkg.release();
        }
        g_pending_package.clear();
        g_active_plugin_key.clear();
        return;
    }

    std::lock_guard<std::mutex> lock(g_registry_mutex);
    BOOST_LOG_TRIVIAL(info) << "Clearing " << g_pending_capabilities.size() << " pending Python plugin capture(s)";
    g_pending_capabilities.clear();
    g_pending_package.clear();
    g_active_plugin_key.clear();
}

void bind_python_api(pybind11::module_& m)
{
    m.doc() = "OrcaSlicer plugin API";

    auto pluginTypes = py::enum_<PluginCapabilityType>(m, "PluginType", "Available plugin capability groups")
                           .value("PrinterConnection", PluginCapabilityType::PrinterConnection)
                           .value("Automation", PluginCapabilityType::Automation)
                           .value("Analysis", PluginCapabilityType::Analysis)
                           .value("Importer", PluginCapabilityType::Importer)
                           .value("Exporter", PluginCapabilityType::Exporter)
                           .value("Visualization", PluginCapabilityType::Visualization)
                           .value("Script", PluginCapabilityType::Script)
                           .value("SlicingPipeline", PluginCapabilityType::SlicingPipeline)
                           .value("Unknown", PluginCapabilityType::Unknown)
                           .export_values();

    py::enum_<PluginResult>(m, "PluginResult", "Execution summary code")
        .value("Success", PluginResult::Success)
        .value("Skipped", PluginResult::Skipped)
        .value("RecoverableError", PluginResult::RecoverableError)
        .value("FatalError", PluginResult::FatalError)
        .export_values();

    py::class_<PluginContext>(m, "PluginContext", "Context shared with plugin entry points")
        .def(py::init<>())
        .def_readwrite("orca_version", &PluginContext::orca_version);

    py::class_<ExecutionResult>(m, "ExecutionResult", "Structured execution outcome")
        .def(py::init<>())
        .def(py::init<PluginResult, std::string, std::string>())
        .def_readwrite("status", &ExecutionResult::status)
        .def_readwrite("message", &ExecutionResult::message)
        .def_readwrite("data", &ExecutionResult::data)
        .def_static("success", &ExecutionResult::success, py::arg("message") = std::string(), py::arg("data") = std::string())
        .def_static("skipped", &ExecutionResult::skipped, py::arg("message") = std::string())
        .def_static("failure", &ExecutionResult::failure, py::arg("status"), py::arg("message"), py::arg("data") = std::string());

    // Config lives at the capability level, not as a global orca.* function: the host reads the
    // owning (plugin_key, capability) straight off the instance the call arrived on, so a
    // capability can only ever address its own config and never has to name itself.
    // Registered on the base, so every capability type (script/gcode/printer-agent) inherits it.
    py::class_<PluginCapabilityInterface, PyPluginInterfaceTrampoline, std::shared_ptr<PluginCapabilityInterface>>(m, "PythonPluginBase")
        .def(py::init<>())
        .def("get_name", &PluginCapabilityInterface::get_name)
        .def("get_type", &PluginCapabilityInterface::get_type)
        .def("on_load", &PluginCapabilityInterface::on_load)
        .def("on_unload", &PluginCapabilityInterface::on_unload)
        .def("has_config_ui", &PluginCapabilityInterface::has_config_ui,
             "Override to return True to replace the host's default JSON editor with your own HTML\n"
             "UI, returned by get_config_ui(). Every capability is configurable and appears in the\n"
             "Plugins dialog's Config tab regardless; this only chooses how its config is edited.")
        .def("get_config_ui", &PluginCapabilityInterface::get_config_ui,
             "Override to return the custom configuration UI as an HTML string. Only called when\n"
             "has_config_ui() is True; an empty result falls back to the default JSON editor.\n"
             "Inside the page, use window.orca.getConfig()/saveConfig() to reach this same config.")
        .def(
            "get_default_config",
            [](const PluginCapabilityInterface& self) {
                nlohmann::json config = self.get_default_config();
                return config.dump();
            },
            "Override to return the config that the Config tab's \"Restore defaults\" action writes\n"
            "back, as a dict. Optional: without it the action stores an empty config, which already\n"
            "restores the defaults of a capability that keeps its stored config sparse and applies\n"
            "its own defaults on read. Override it to write an explicit starting config instead.\n"
            "Calling it returns that config as a JSON string.")
        .def(
            "get_config",
            [](const PluginCapabilityInterface& self) {
                nlohmann::json config = capability_get_config(self);
                return config.dump();
            },
            "Return this capability's stored config as a JSON string — json.loads() it to use.\n"
            "\"{}\" if it has never been saved, so the parsed result is always indexable.")
        .def(
            "get_config_version", [](const PluginCapabilityInterface& self) { return capability_get_config_version(self); },
            "Return the plugin version that last wrote this capability's config, so a newer\n"
            "release can spot a stale config and migrate it. Empty string if never saved.")
        .def(
            "save_config",
            [](const PluginCapabilityInterface& self, const std::string& config_str) {
                nlohmann::json config = nlohmann::json::parse(config_str, nullptr, /* allow_exceptions */ false);
                if (config.is_discarded()) {
                    // Refused rather than stored: the caller gets False, and the previously stored
                    // config is left alone. Logged because False alone does not say why.
                    BOOST_LOG_TRIVIAL(error) << "save_config: capability '" << self.get_name() << "' passed a config that is not valid JSON";
                    return false;
                }
                return capability_save_config(self, config);
            },
            py::arg("config"),
            "Persist this capability's config, given as a JSON string (e.g. json.dumps(cfg)).\n"
            "The plugin key, capability name and version are supplied by the host. Returns False if\n"
            "the string is not valid JSON, or if the config file could not be written.");

    // Expose the package marker base as orca.base. @orca.plugin later verifies that the
    // decorated class derives from this exact pybind-registered C++ type.
    py::class_<PyPluginPackage, PyPluginPackageTrampoline>(m, "base")
        .def(py::init<>())
        .def("register_capabilities", &PyPluginPackage::register_capabilities);

    BOOST_LOG_TRIVIAL(debug) << "Registering embedded Python plugin type bindings";

    // Make sure you register your bindings here
    PrinterAgentPluginCapability::RegisterBindings(m, pluginTypes);
    ScriptPluginCapability::RegisterBindings(m, pluginTypes);
    SlicingPipelinePluginCapability::RegisterBindings(m, pluginTypes);
    PluginHost::RegisterBindings(m);
    BOOST_LOG_TRIVIAL(debug) << "Registered ScriptPluginCapability Python bindings";

    m.def(
        "register_capability",
        [](py::object plugin_cls) {
            if (g_active_plugin_key.empty()) {
                throw py::value_error("register_capability() called outside plugin discovery context");
            }

            // Store capability classes only, not instances. Finalization instantiates them
            // after the package has registered the full set for this plugin.
            py::handle base = py::type::of<PluginCapabilityInterface>();
            const int is_subclass = PyObject_IsSubclass(plugin_cls.ptr(), base.ptr());
            if (is_subclass != 1) {
                if (is_subclass < 0)
                    PyErr_Clear();
                throw py::value_error("Registered class must inherit from a PluginCapability base");
            }

            std::lock_guard<std::mutex> lock(g_registry_mutex);
            g_pending_capabilities[g_active_plugin_key].push_back(std::move(plugin_cls));
            BOOST_LOG_TRIVIAL(debug) << "Registered Python plugin capability class for key " << g_active_plugin_key;
        },
        R"pbdoc(Register a PluginCapability subclass while OrcaSlicer loads your module.)pbdoc");

    m.def("plugin", [](py::object cls) {
        if (g_active_plugin_key.empty())
            throw py::value_error("@orca.plugin used outside plugin discovery context");
        if (!PyType_Check(cls.ptr()))
            throw py::value_error("@orca.plugin must decorate a class");
        // The decorator is only a marker/capture hook. It records the package class now;
        // finalize_plugin_capture() instantiates it later and calls register_capabilities().
        py::handle base = py::type::of<PyPluginPackage>();
        const int is_subclass = PyObject_IsSubclass(cls.ptr(), base.ptr());
        if (is_subclass != 1) {
            if (is_subclass < 0)
                PyErr_Clear();
            throw py::value_error("@orca.plugin must decorate a subclass of orca.base");
        }
        {
            std::lock_guard<std::mutex> lock(g_registry_mutex);
            auto& slot = g_pending_package[g_active_plugin_key];
            if (slot)
                throw py::value_error("multiple @orca.plugin classes registered; exactly one is allowed per plugin");
            slot = cls;
        }
        return cls; // decorator returns the class unchanged
    }, R"pbdoc(Mark the single plugin package class (the orca.base subclass) for this file.)pbdoc");

}

} // namespace Slic3r

#ifdef ORCA_PYTHON_STUBGEN_MODULE
PYBIND11_MODULE(orca, m) { Slic3r::bind_python_api(m); }
#else
PYBIND11_EMBEDDED_MODULE(orca, m) { Slic3r::bind_python_api(m); }
#endif