// *****************************************************************************
// Copyright (C) 2018 TypeFox 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-only WITH Classpath-exception-2.0
// *****************************************************************************

import * as React from 'react';
import { injectable, postConstruct, interfaces, Container } from 'inversify';
import { DisposableCollection } from '../../common/disposable';
import { TreeWidget, TreeNode, createTreeContainer, TreeProps, TreeModel, TREE_NODE_SEGMENT_GROW_CLASS } from '../tree';
import { TreeSource, TreeElement } from './tree-source';
import { SourceTree, TreeElementNode, TreeSourceNode } from './source-tree';

@injectable()
export class SourceTreeWidget extends TreeWidget {

    static createContainer(parent: interfaces.Container, props?: Partial<TreeProps>): Container {
        const child = createTreeContainer(parent, {
            props,
            tree: SourceTree,
            widget: SourceTreeWidget,
        });

        return child;
    }

    @postConstruct()
    protected override init(): void {
        super.init();
        this.addClass('theia-source-tree');
        this.toDispose.push(this.model.onOpenNode(node => {
            if (TreeElementNode.is(node) && node.element.open) {
                node.element.open();
            }
        }));
    }

    protected readonly toDisposeOnSource = new DisposableCollection();
    get source(): TreeSource | undefined {
        const root = this.model.root;
        return TreeSourceNode.is(root) ? root.source : undefined;
    }
    set source(source: TreeSource | undefined) {
        if (this.source === source) {
            return;
        }
        this.toDisposeOnSource.dispose();
        this.toDispose.push(this.toDisposeOnSource);
        this.model.root = TreeSourceNode.to(source);
        if (source) {
            this.toDisposeOnSource.push(source.onDidChange(() => this.model.refresh()));
        }
    }

    get selectedElement(): TreeElement | undefined {
        const node = this.model.selectedNodes[0];
        return TreeElementNode.is(node) && node.element || undefined;
    }

    protected override renderTree(model: TreeModel): React.ReactNode {
        if (TreeSourceNode.is(model.root) && model.root.children.length === 0) {
            const { placeholder } = model.root.source;
            if (placeholder) {
                return <div className='theia-tree-source-node-placeholder noselect'>{placeholder}</div>;
            }
        }
        return super.renderTree(model);

    }

    protected override renderCaption(node: TreeNode): React.ReactNode {
        if (TreeElementNode.is(node)) {
            const classNames = this.createTreeElementNodeClassNames(node);
            return <div className={classNames.join(' ')}>{node.element.render(this)}</div>;
        }
        return undefined;
    }
    protected createTreeElementNodeClassNames(node: TreeElementNode): string[] {
        return [TREE_NODE_SEGMENT_GROW_CLASS];
    }

    override storeState(): object {
        // no-op
        return {};
    }
    protected superStoreState(): object {
        return super.storeState();
    }
    override restoreState(state: object): void {
        // no-op
    }
    protected superRestoreState(state: object): void {
        super.restoreState(state);
        return;
    }

}