// *****************************************************************************
// Copyright (C) 2017 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 { inject, injectable } from '@theia/core/shared/inversify';
import URI from '@theia/core/lib/common/uri';
import { DiffUris } from '@theia/core/lib/browser/diff-uris';
import { open, OpenerService, OpenerOptions } from '@theia/core/lib/browser';
import { MessageService } from '@theia/core/lib/common/message-service';
import { FileService } from '@theia/filesystem/lib/browser/file-service';
import { nls } from '@theia/core';

@injectable()
export class DiffService {

    @inject(FileService) protected readonly fileService: FileService;
    @inject(OpenerService) protected readonly openerService: OpenerService;
    @inject(MessageService) protected readonly messageService: MessageService;

    public async openDiffEditor(left: URI, right: URI, label?: string, options?: OpenerOptions): Promise<void> {
        if (left.scheme === 'file' && right.scheme === 'file') {
            const [resolvedLeft, resolvedRight] = await this.fileService.resolveAll([{ resource: left }, { resource: right }]);
            if (resolvedLeft.success && resolvedRight.success) {
                const leftStat = resolvedLeft.stat;
                const rightStat = resolvedRight.stat;
                if (leftStat && rightStat) {
                    if (!leftStat.isDirectory && !rightStat.isDirectory) {
                        const uri = DiffUris.encode(left, right, label);
                        await open(this.openerService, uri, options);
                    } else {
                        const details =
                            leftStat.isDirectory && rightStat.isDirectory ?
                                nls.localize('theia/workspace/bothAreDirectories', 'Both resources are directories.') :
                                nls.localize('theia/workspace/isDirectory', "'{0}' is a directory.", leftStat.isDirectory ? left.path.base : right.path.base);
                        this.messageService.warn(nls.localize('theia/workspace/directoriesCannotBeCompared', 'Directories cannot be compared. {0}', details));
                    }
                }
            }
        } else {
            const uri = DiffUris.encode(left, right, label);
            await open(this.openerService, uri, options);
        }
    }
}