// *****************************************************************************
// Copyright (C) 2019 RedHat 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 { injectable, inject } from 'inversify';
import { isFirefox } from './browser';
import { ClipboardService } from './clipboard-service';
import { Emitter, Event } from '../common/event';
import { ILogger } from '../common/logger';
import { MessageService } from '../common/message-service';
import { nls } from '../common/nls';

export interface NavigatorClipboard {
    readText(): Promise<string>;
    writeText(value: string): Promise<void>;
}
export interface PermissionStatus {
    state: 'granted' | 'prompt' | 'denied'
}
export interface NavigatorPermissions {
    query(options: { name: string }): Promise<PermissionStatus>
}

@injectable()
export class BrowserClipboardService implements ClipboardService {

    @inject(MessageService)
    protected readonly messageService: MessageService;

    @inject(ILogger)
    protected readonly logger: ILogger;

    protected readonly onDidWriteTextEmitter = new Emitter<string>();
    readonly onDidWriteText: Event<string> = this.onDidWriteTextEmitter.event;

    async readText(): Promise<string> {
        let permission;
        try {
            permission = await this.queryPermission('clipboard-read');
        } catch (e1) {
            this.logger.error('Failed checking a clipboard-read permission.', e1);
            // in FireFox, Clipboard API isn't gated with the permissions
            try {
                return await this.getClipboardAPI().readText();
            } catch (e2) {
                this.logger.error('Failed reading clipboard content.', e2);
                if (isFirefox) {
                    this.messageService.warn(nls.localize(
                        'theia/navigator/clipboardWarnFirefox',
                        // eslint-disable-next-line max-len
                        "Clipboard API is not available. It can be enabled by '{0}' preference on '{1}' page. Then reload Theia. Note, it will allow FireFox getting full access to the system clipboard.", 'dom.events.testing.asyncClipboard', 'about:config'
                    ));
                }
                return '';
            }
        }
        if (permission.state === 'denied') {
            // most likely, the user intentionally denied the access
            this.messageService.warn(nls.localize(
                'theia/navigator/clipboardWarn',
                "Access to the clipboard is denied. Check your browser's permission."
            ));
            return '';
        }
        return this.getClipboardAPI().readText();
    }

    async writeText(value: string): Promise<void> {
        let permission;
        try {
            permission = await this.queryPermission('clipboard-write');
        } catch (e1) {
            this.logger.error('Failed checking a clipboard-write permission.', e1);
            // in FireFox, Clipboard API isn't gated with the permissions
            try {
                await this.getClipboardAPI().writeText(value);
                this.onDidWriteTextEmitter.fire(value);
                return;
            } catch (e2) {
                this.logger.error('Failed writing to the clipboard.', e2);
                if (isFirefox) {
                    this.messageService.warn(nls.localize(
                        'theia/core/navigator/clipboardWarnFirefox',
                        // eslint-disable-next-line max-len
                        "Clipboard API is not available. It can be enabled by '{0}' preference on '{1}' page. Then reload Theia. Note, it will allow FireFox getting full access to the system clipboard.", 'dom.events.testing.asyncClipboard', 'about:config'
                    ));
                }
                return;
            }
        }
        if (permission.state === 'denied') {
            // most likely, the user intentionally denied the access
            this.messageService.warn(nls.localize(
                'theia/core/navigator/clipboardWarn',
                "Access to the clipboard is denied. Check your browser's permission."
            ));
            return;
        }
        await this.getClipboardAPI().writeText(value);
        this.onDidWriteTextEmitter.fire(value);
    }

    protected async queryPermission(name: string): Promise<PermissionStatus> {
        if ('permissions' in navigator) {
            return (<NavigatorPermissions>navigator['permissions']).query({ name: name });
        }
        throw new Error('Permissions API unavailable');
    }

    protected getClipboardAPI(): NavigatorClipboard {
        if ('clipboard' in navigator) {
            return (<NavigatorClipboard>navigator['clipboard']);
        }
        throw new Error('Async Clipboard API unavailable');
    }
}
