// SPDX-License-Identifier: LGPL-2.1-or-later

/***************************************************************************
 *   Copyright (c) 2025 Kindred Systems                                    *
 *                                                                         *
 *   This file is part of Kindred Create.                                  *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  is distributed in the hope that it will be useful,      *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/

#ifndef GUI_EDITINGCONTEXT_H
#define GUI_EDITINGCONTEXT_H

#include <functional>
#include <QObject>
#include <QString>
#include <QStringList>

#include <FCGlobal.h>

namespace Gui
{

class Document;
class MDIView;
class ViewProviderDocumentObject;

/// Snapshot of the resolved editing context.
struct GuiExport EditingContext
{
    QString id;                    // e.g. "sketcher.edit", "partdesign.body"
    QString label;                 // e.g. "Sketcher: Sketch001"
    QString color;                 // Catppuccin Mocha hex, e.g. "#a6e3a1"
    QStringList toolbars;          // toolbar names to ForceAvailable
    QStringList breadcrumb;        // e.g. ["Body", "Sketch001", "[editing]"]
    QStringList breadcrumbColors;  // per-segment color hex values
};

/// Definition used when registering a context.
struct GuiExport ContextDefinition
{
    QString id;
    QString labelTemplate;  // supports {name} placeholder
    QString color;
    QStringList toolbars;
    int priority = 0;  // higher = checked first during resolve

    /// Return true if this context matches the current application state.
    std::function<bool()> match;
};

/// Definition for an overlay context (additive, not exclusive).
struct GuiExport OverlayDefinition
{
    QString id;
    QStringList toolbars;

    /// Return true if the overlay should be active.
    std::function<bool()> match;
};

/**
 * Singleton that resolves the current editing context from application state
 * and drives toolbar visibility and the breadcrumb display.
 *
 * Built-in contexts (PartDesign, Sketcher, Assembly, Spreadsheet) are registered
 * at construction.  Third-party modules register via registerContext() /
 * registerOverlay() from Python or C++.
 */
class GuiExport EditingContextResolver: public QObject
{
    Q_OBJECT

public:
    static EditingContextResolver* instance();
    static void destruct();

    void registerContext(const ContextDefinition& def);
    void unregisterContext(const QString& id);

    void registerOverlay(const OverlayDefinition& def);
    void unregisterOverlay(const QString& id);

    /// Inject additional commands into a context's toolbar.
    void injectCommands(const QString& contextId, const QString& toolbarName, const QStringList& commands);

    /// Force a re-resolve (e.g. after workbench switch).
    void refresh();

    EditingContext currentContext() const;

Q_SIGNALS:
    void contextChanged(const EditingContext& ctx);

private:
    EditingContextResolver();
    ~EditingContextResolver() override;

    EditingContext resolve() const;
    void applyContext(const EditingContext& ctx);
    QStringList buildBreadcrumb(const EditingContext& ctx) const;
    QStringList buildBreadcrumbColors(const EditingContext& ctx) const;

    // Signal handlers
    void onInEdit(const ViewProviderDocumentObject& vp);
    void onResetEdit(const ViewProviderDocumentObject& vp);
    void onActiveDocument(const Document& doc);
    void onActivateView(const MDIView* view);

    void registerBuiltinContexts();

    struct Private;
    Private* d;

    static EditingContextResolver* _instance;
};

}  // namespace Gui

#endif  // GUI_EDITINGCONTEXT_H