/********************************************************************************
 * Copyright (c) 2019-2025 EclipseSource and others.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the Eclipse
 * Public License v. 2.0 are satisfied: GNU General Public License, version 2
 * with the GNU Classpath Exception which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 ********************************************************************************/
// based on: https://github.com/eclipse-sprotty/sprotty-theia/blob/v0.12.0/src/sprotty/theia-sprotty-context-menu-service.ts
import { Anchor, ClientMenuItem, FocusStateChangedAction, IActionDispatcher, IContextMenuService } from '@eclipse-glsp/client';
import { Command, CommandHandler, CommandRegistry, Disposable, MenuAction, MenuModelRegistry, MenuPath } from '@theia/core';
import { ApplicationShell, ContextMenuRenderer } from '@theia/core/lib/browser';
import { inject, injectable } from 'inversify';
import { getDiagramWidget, GLSPDiagramWidget } from './diagram/glsp-diagram-widget';

export namespace TheiaGLSPContextMenu {
    export const CONTEXT_MENU: MenuPath = ['theia-glsp-context-menu'];
}

@injectable()
export class TheiaContextMenuService implements IContextMenuService {
    protected timeout?: number;
    protected disposables: DisposableItem[] = [];

    @inject(ContextMenuRenderer)
    protected readonly contextMenuRenderer: ContextMenuRenderer;

    @inject(MenuModelRegistry)
    protected readonly menuProvider: MenuModelRegistry;

    @inject(CommandRegistry)
    protected readonly commandRegistry: CommandRegistry;

    @inject(ApplicationShell)
    protected readonly shell: ApplicationShell;

    protected actionDispatcher?: IActionDispatcher;

    connect(actionDispatcher: IActionDispatcher): void {
        this.actionDispatcher = actionDispatcher;
    }

    get diagramWidget(): GLSPDiagramWidget | undefined {
        return getDiagramWidget(this.shell);
    }

    show(items: ClientMenuItem[], anchor: Anchor, onHide?: () => void): void {
        const context = this.diagramWidget?.node;
        if (!context) {
            console.warn('No context available for context menu');
            return;
        }
        this.cleanUpNow();

        this.disposables = this.register(TheiaGLSPContextMenu.CONTEXT_MENU, items);
        const renderOptions = {
            menuPath: TheiaGLSPContextMenu.CONTEXT_MENU,
            anchor: anchor,
            context,
            onHide: () => {
                if (onHide) {
                    onHide();
                }
                this.scheduleCleanup();
                this.restoreFocus();
            }
        };
        this.contextMenuRenderer.render(renderOptions);
    }

    protected register(menuPath: string[], items: ClientMenuItem[]): DisposableItem[] {
        const disposables: DisposableItem[] = [];
        for (const item of items) {
            if (item.children && item.children.length > 0) {
                const menuPathOfItem = item.group ? [...menuPath, item.group] : menuPath;
                disposables.push(this.registerSubmenu(menuPathOfItem, item));
                disposables.push(...this.register([...menuPathOfItem, item.id], item.children));
            } else {
                disposables.push(this.registerCommand(menuPath, item));
                disposables.push(this.registerMenuAction(menuPath, item));
            }
        }
        return disposables;
    }

    protected registerSubmenu(menuPath: string[], item: ClientMenuItem): DisposableItem {
        return this.menuProvider.registerSubmenu([...menuPath, item.id], item.label, { icon: item.icon });
    }

    protected registerCommand(menuPath: string[], item: ClientMenuItem): DisposableItem {
        const command: Command = { id: commandId(menuPath, item), label: item.label, iconClass: item.icon };
        const disposable = this.commandRegistry.registerCommand(command, new GLSPCommandHandler(item, this.actionDispatcher));
        return new DisposableCommand(command, disposable);
    }

    protected registerMenuAction(menuPath: string[], item: ClientMenuItem): DisposableItem {
        const { label, sortString: order, isEnabled, isToggled, isVisible } = item;
        const menuAction = { label, order, isEnabled, isToggled, isVisible, commandId: commandId(menuPath, item) };
        const menuPathOfItem = item.group ? [...menuPath, item.group] : menuPath;
        const disposable = this.menuProvider.registerMenuAction(menuPathOfItem, menuAction);
        return new DisposableMenuAction(menuAction, disposable);
    }

    protected cleanUpNow(): void {
        window.clearTimeout(this.timeout);
        this.cleanUp();
    }

    protected scheduleCleanup(): void {
        this.timeout = window.setTimeout(() => {
            this.cleanUp();
        }, 200);
    }

    protected cleanUp(): void {
        this.disposables.forEach(disposable => disposable.dispose(this.menuProvider, this.commandRegistry));
        this.disposables = [];
    }

    protected restoreFocus(): void {
        const widget = this.diagramWidget;
        if (!widget || widget.hasFocus) {
            return;
        }
        widget.actionDispatcher.dispatch(FocusStateChangedAction.create(true));
    }
}

class GLSPCommandHandler implements CommandHandler {
    constructor(
        readonly menuItem: ClientMenuItem,
        readonly actionDispatcher?: IActionDispatcher
    ) {}

    execute(...args: any[]): void {
        if (this.actionDispatcher && this.menuItem.actions) {
            this.actionDispatcher.dispatchAll(this.menuItem.actions);
        }
    }

    isEnabled(...args: any[]): boolean {
        return getBooleanValue(this.menuItem.isEnabled, true);
    }

    isVisible(...args: any[]): boolean {
        return getBooleanValue(this.menuItem.isVisible, true);
    }

    isToggled(...args: any[]): boolean {
        return getBooleanValue(this.menuItem.isToggled, false);
    }
}

interface DisposableItem {
    dispose(menuProvider: MenuModelRegistry, commandRegistry: CommandRegistry): void;
}

class DisposableMenuAction implements DisposableItem {
    constructor(
        protected readonly menuAction: MenuAction,
        protected readonly disposable: Disposable
    ) {}
    dispose(menuProvider: MenuModelRegistry, commandRegistry: CommandRegistry): void {
        menuProvider.unregisterMenuAction(this.menuAction);
        this.disposable.dispose();
    }
}

class DisposableCommand implements DisposableItem {
    constructor(
        protected readonly command: Command,
        protected readonly disposable: Disposable
    ) {}
    dispose(menuProvider: MenuModelRegistry, commandRegistry: CommandRegistry): void {
        commandRegistry.unregisterCommand(this.command);
        this.disposable.dispose();
    }
}

function commandId(menuPath: string[], item: any): string {
    return menuPath.join('.') + '.' + item.id;
}

function getBooleanValue(value: any, defaultValue: boolean): boolean {
    let returnVal = defaultValue;
    if (isFunction(value)) {
        returnVal = value();
    } else if (isBoolean(value)) {
        returnVal = value;
    }
    return returnVal;
}

function isFunction(value: () => boolean | boolean): value is () => boolean {
    return !!(value && value.constructor && value.apply);
}

function isBoolean(value: () => boolean | boolean): boolean {
    return typeof value === 'boolean';
}