// (C) Copyright 2015 Moodle Pty Ltd.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import { Injectable } from '@angular/core';
import { Clipboard } from '@ionic-native/clipboard/ngx';

/**
 * Emulates the Cordova Clipboard plugin in browser.
 */
@Injectable()
export class ClipboardMock extends Clipboard {

    protected copyTextarea: HTMLTextAreaElement;

    constructor() {
        super();

        // In browser the text must be selected in order to copy it. Create a hidden textarea to put the text in it.
        this.copyTextarea = document.createElement('textarea');
        this.copyTextarea.className = 'core-browser-copy-area';
        this.copyTextarea.setAttribute('aria-hidden', 'true');
        document.body.appendChild(this.copyTextarea);
    }

    /**
     * Copy some text to the clipboard.
     *
     * @param text The text to copy.
     * @returns Promise resolved when copied.
     */
    copy(text: string): Promise<void> {
        return new Promise((resolve, reject): void => {
            // Put the text in the hidden textarea and select it.
            this.copyTextarea.innerHTML = text;
            this.copyTextarea.select();

            try {
                if (document.execCommand('copy')) {
                    resolve();
                } else {
                    reject();
                }
            } catch (err) {
                reject();
            }

            this.copyTextarea.innerHTML = '';
        });
    }

    /*
     * Get the text stored in the clipboard.
     *
     * @returns Promise resolved with the text.
     */
    paste(): Promise<string> {
        return new Promise((resolve, reject): void => {
            // Paste the text in the hidden textarea and get it.
            this.copyTextarea.innerHTML = '';
            this.copyTextarea.select();

            try {
                if (document.execCommand('paste')) {
                    resolve(this.copyTextarea.innerHTML);
                } else {
                    reject();
                }
            } catch (err) {
                reject();
            }

            this.copyTextarea.innerHTML = '';
        });
    }

}
