OrcaSlicer/src/libslic3r/LifecycleEvents.hpp

#pragma once

// LifecycleEvents.hpp
// --------------------
// Application lifecycle events (project, slicing, plate editing, preset, printer connection, and
// job activity) that other subsystems -- chiefly the plugin layer above libslic3r -- may want to
// observe. Lives in libslic3r rather than the plugin layer because some events fire from inside
// the slicing engine itself; see fire_lifecycle_event() below.

#include <functional>
#include <condition_variable>
#include <cstddef>
#include <mutex>
#include <string>
#include <utility>

namespace Slic3r
{
    enum class LifecycleEvent {
        // Project (3mf)
        NewProject,
        ProjectOpened,
        ProjectBeforeSave,
        ProjectAfterSave,
        ProjectClosed,
        ProjectDirtyChanged,

        // Slicing pipeline
        SliceStarted,
        SliceGeometryFinished,
        GCodeExportStarted,
        GCodeExportFinished,
        SlicingJobComplete,

        // Plate/model editing
        ObjectAdded,
        ObjectDeleted,
        ObjectTransformed,
        ObjectChanged,
        ObjectRenamed,
        PlateCreated,
        PlateDeleted,
        PlateSelected,
        PlateRenamed,

        // Preset
        PresetSelected,
        PresetSaved,

        // Printer/device
        PrintStateChanged,
        DeviceOnline,
        DeviceOffline,
        DeviceDiscovered,
        DeviceSelected,
        UploadStarted,
        UploadFinished,

        // Print/send jobs
        PrintJobStarted,
        PrintJobFinished,
        SendJobStarted,
        SendJobFinished,
    };

    // Scoped so callers must qualify (LifecycleEvtCode::Error, not ERROR) -- ERROR/OK collide with
    // Windows macros (wingdi.h) as unqualified names.
    enum class LifecycleEvtCode { Ok, Error, Warn };

    struct LifecycleEventContext
    {
        // The primary subject identifier for the event. This is event-specific (for example, a
        // project/output path, preset name, device id, or object name), must not contain status or
        // prose, and may be empty when the event has no single subject.
        std::string name;

        // Outcome of the operation represented by the event. For state-change and start events,
        // Ok means that the event occurred; it does not imply that a future operation succeeded.
        LifecycleEvtCode code = LifecycleEvtCode::Ok;

        // Optional human-readable detail or diagnostic text. It is not a stable parsing contract;
        // machine-readable data should be represented by a dedicated field or event instead.
        std::string msg;

        // Stable subject/object identifier, when the source model provides one.
        std::string id;

        // Previous value for rename and other before/after events.
        std::string previous_name;

        // Device identifier for printer and job events.
        std::string device_id;

        // Job identifier when the originating queue/task provides one.
        std::string job_id;

        // Source subsystem or operation detail, suitable for filtering but not guaranteed to be
        // exhaustive across versions.
        std::string source;

        // Plate, object, or volume index when the source uses an index rather than a stable id.
        int index = -1;

        // Aggregate project dirty state for ProjectDirtyChanged.
        bool dirty = false;

        // Optional host-side cancellation probe. Background slicing and G-code export events set
        // this to the originating Print's cancellation state so dispatch can stop before calling
        // the next capability. It is intentionally not exposed through the Python payload API.
        std::function<bool()> cancellation_check;
    };

    inline std::string lifecycle_event_to_string(LifecycleEvent event)
    {
        switch (event) {
        case LifecycleEvent::NewProject: return "NewProject";
        case LifecycleEvent::ProjectOpened: return "ProjectOpened";
        case LifecycleEvent::ProjectBeforeSave: return "ProjectBeforeSave";
        case LifecycleEvent::ProjectAfterSave: return "ProjectAfterSave";
        case LifecycleEvent::ProjectClosed: return "ProjectClosed";
        case LifecycleEvent::ProjectDirtyChanged: return "ProjectDirtyChanged";

        case LifecycleEvent::SliceStarted: return "SliceStarted";
        case LifecycleEvent::SliceGeometryFinished: return "SliceGeometryFinished";
        case LifecycleEvent::GCodeExportStarted: return "GCodeExportStarted";
        case LifecycleEvent::GCodeExportFinished: return "GCodeExportFinished";
        case LifecycleEvent::SlicingJobComplete: return "SlicingJobComplete";

        case LifecycleEvent::ObjectAdded: return "ObjectAdded";
        case LifecycleEvent::ObjectDeleted: return "ObjectDeleted";
        case LifecycleEvent::ObjectTransformed: return "ObjectTransformed";
        case LifecycleEvent::ObjectChanged: return "ObjectChanged";
        case LifecycleEvent::ObjectRenamed: return "ObjectRenamed";
        case LifecycleEvent::PlateCreated: return "PlateCreated";
        case LifecycleEvent::PlateDeleted: return "PlateDeleted";
        case LifecycleEvent::PlateSelected: return "PlateSelected";
        case LifecycleEvent::PlateRenamed: return "PlateRenamed";

        case LifecycleEvent::PresetSelected: return "PresetSelected";
        case LifecycleEvent::PresetSaved: return "PresetSaved";
        case LifecycleEvent::PrintStateChanged: return "PrintStateChanged";

        case LifecycleEvent::DeviceOnline: return "DeviceOnline";
        case LifecycleEvent::DeviceOffline: return "DeviceOffline";
        case LifecycleEvent::DeviceDiscovered: return "DeviceDiscovered";
        case LifecycleEvent::DeviceSelected: return "DeviceSelected";

        case LifecycleEvent::UploadStarted: return "UploadStarted";
        case LifecycleEvent::UploadFinished: return "UploadFinished";
        case LifecycleEvent::PrintJobStarted: return "PrintJobStarted";
        case LifecycleEvent::PrintJobFinished: return "PrintJobFinished";
        case LifecycleEvent::SendJobStarted: return "SendJobStarted";
        case LifecycleEvent::SendJobFinished: return "SendJobFinished";
        default: return "Unknown";
        }
    }

    inline std::string lifecycle_evt_code_to_string(LifecycleEvtCode code)
    {
        switch (code) {
        case LifecycleEvtCode::Ok: return "Ok";
        case LifecycleEvtCode::Error: return "Error";
        case LifecycleEvtCode::Warn: return "Warn";
        default: return "Unknown";
        }
    }

    // Global cross-layer seam (mirrors ConfigBase::set_resolve_capability_fn): any libslic3r code can
    // fire a lifecycle event without depending on the plugin layer above it, which installs the
    // dispatcher here at startup. Not tied to Print/GCode specifically, since nothing here should
    // require callers to hold a Print& just to report an event.
    using LifecycleHookFn = std::function<void(LifecycleEvent, const LifecycleEventContext&)>;

    namespace detail {

    struct LifecycleHookState
    {
        std::mutex              mutex;
        std::condition_variable cv;
        LifecycleHookFn         fn;
        std::size_t             active_dispatches = 0;
        bool                    accepting        = false;
    };

    inline LifecycleHookState& lifecycle_hook_state()
    {
        static LifecycleHookState state;
        return state;
    }

    class LifecycleDispatchGuard
    {
    public:
        explicit LifecycleDispatchGuard(LifecycleHookState& state) : m_state(state) {}

        ~LifecycleDispatchGuard()
        {
            std::lock_guard<std::mutex> lock(m_state.mutex);
            --m_state.active_dispatches;
            if (m_state.active_dispatches == 0)
                m_state.cv.notify_all();
        }

        LifecycleDispatchGuard(const LifecycleDispatchGuard&)            = delete;
        LifecycleDispatchGuard& operator=(const LifecycleDispatchGuard&) = delete;

    private:
        LifecycleHookState& m_state;
    };

    } // namespace detail

    // Installing a hook starts accepting dispatches. Passing an empty function stops accepting
    // new dispatches, detaches the hook, and waits for callbacks already in progress to finish.
    // This is used during plugin shutdown so plugin code cannot be unloaded while a lifecycle
    // callback is still executing. The empty-function path must not be called from inside the
    // lifecycle callback itself.
    inline void set_lifecycle_hook_fn(LifecycleHookFn fn)
    {
        detail::LifecycleHookState& state = detail::lifecycle_hook_state();
        if (fn) {
            std::lock_guard<std::mutex> lock(state.mutex);
            state.fn        = std::move(fn);
            state.accepting = true;
            return;
        }

        std::unique_lock<std::mutex> lock(state.mutex);
        state.accepting = false;
        state.fn        = nullptr;
        state.cv.wait(lock, [&state] { return state.active_dispatches == 0; });
    }

    inline void fire_lifecycle_event(LifecycleEvent event, const LifecycleEventContext& ctx)
    {
        detail::LifecycleHookState& state = detail::lifecycle_hook_state();
        LifecycleHookFn             fn;
        {
            std::lock_guard<std::mutex> lock(state.mutex);
            if (!state.accepting || !state.fn)
                return;
            fn = state.fn;
            ++state.active_dispatches;
        }

        detail::LifecycleDispatchGuard guard(state);
        fn(event, ctx);
    }
}