// Copyright © 2010-2015 The CefSharp Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.

using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using CefSharp.OffScreen;
using System.Threading.Tasks;

namespace CefSharp.MinimalExample.OffScreen
{
    public class Program
    {
        private static ChromiumWebBrowser browser;

        public static void Main(string[] args)
        {
            const string testUrl = "https://www.google.com/";

            Console.WriteLine("This example application will load {0}, take a screenshot, and save it to your desktop.", testUrl);
            Console.WriteLine("You may see Chromium debugging output, please wait...");
            Console.WriteLine();

            //Monitor parent process exit and close subprocesses if parent process exits first
            //This will at some point in the future becomes the default
            CefSharpSettings.SubprocessExitIfParentProcessClosed = true;

            var settings = new CefSettings()
            {
                //By default CefSharp will use an in-memory cache, you need to specify a Cache Folder to persist data
                CachePath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "CefSharp\\Cache")
            };

            //Perform dependency check to make sure all relevant resources are in our output directory.
            Cef.Initialize(settings, performDependencyCheck: true, browserProcessHandler: null);

            // Create the offscreen Chromium browser.
            browser = new ChromiumWebBrowser(testUrl);

            // An event that is fired when the first page is finished loading.
            // This returns to us from another thread.
            browser.LoadingStateChanged += BrowserLoadingStateChanged;

            // We have to wait for something, otherwise the process will exit too soon.
            Console.ReadKey();

            // Clean up Chromium objects.  You need to call this in your application otherwise
            // you will get a crash when closing.
            Cef.Shutdown();
        }

        private static async void BrowserLoadingStateChanged(object sender, LoadingStateChangedEventArgs e)
        {
            // Check to see if loading is complete - this event is called twice, one when loading starts
            // second time when it's finished
            // (rather than an iframe within the main frame).
            if (!e.IsLoading)
            {
                // Remove the load event handler, because we only want one snapshot of the initial page.
                browser.LoadingStateChanged -= BrowserLoadingStateChanged;

                const string script = "(function(){ var elm = document.getElementById('lst-ib'); elm.value = 'CefSharp Was Here!'; return document.getElementsByName('btnK')[0].getBoundingClientRect(); })();";

                var jsResponse = await browser.EvaluateScriptAsync(script);

                if(jsResponse.Success)
                {
                    dynamic domRect = jsResponse.Result;

                    var x = (int)(domRect.x + (domRect.width / 2));
                    var y = (int)(domRect.y + (domRect.height / 2));

                    var host = browser.GetBrowserHost();

                    host.SendMouseClickEvent(x, y, MouseButtonType.Left, false, 1, CefEventFlags.None);
                    Thread.Sleep(15);
                    host.SendMouseClickEvent(x, y, MouseButtonType.Left, true, 1, CefEventFlags.None);

                    //Give the browser a little time to render
                    Thread.Sleep(2500);
                    // Wait for the screenshot to be taken.
                    var bitmap = await browser.ScreenshotAsync();

                    // Make a file to save it to (e.g. C:\Users\jan\Desktop\CefSharp screenshot.png)
                    var screenshotPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "CefSharp screenshot.png");

                    Console.WriteLine();
                    Console.WriteLine("Screenshot ready. Saving to {0}", screenshotPath);

                    // Save the Bitmap to the path.
                    // The image type is auto-detected via the ".png" extension.
                    bitmap.Save(screenshotPath);

                    // We no longer need the Bitmap.
                    // Dispose it to avoid keeping the memory alive.  Especially important in 32-bit applications.
                    bitmap.Dispose();

                    Console.WriteLine("Screenshot saved.  Launching your default image viewer...");

                    // Tell Windows to launch the saved image.
                    Process.Start(screenshotPath);

                    Console.WriteLine("Image viewer launched.  Press any key to exit.");
                }
            }
        }
    }
}