using System.Drawing;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.AspNetCore.Mvc.Rendering;

namespace SelectPdf.Samples.Pages
{
    public class WebElementsLocationModel : PageModel
    {
        public void OnGet()
        {
            DdlRenderingEngine = "WebKit";
        }

        [BindProperty]
        public string TxtUrl { get; set; }

        [BindProperty]
        public string DdlRenderingEngine { get; set; }

        public List<SelectListItem> RenderingEngines { get; } = new List<SelectListItem>
        {
            new SelectListItem { Value = "WebKit", Text = "WebKit" },
            new SelectListItem { Value = "WebKitRestricted", Text = "WebKit Restricted" },
            new SelectListItem { Value = "Blink", Text = "Blink" },
            new SelectListItem { Value = "Chromium", Text = "Chromium" },
        };

        [BindProperty]
        public string TxtElements { get; set; }

        public IActionResult OnPost()
        {
            RenderingEngine renderingEngine =
                (RenderingEngine)Enum.Parse(typeof(RenderingEngine), DdlRenderingEngine, true);

            // instantiate a html to pdf converter object
            HtmlToPdf converter = new HtmlToPdf();

            // set the css selectors for the web elements
            // whose positions will be retrieved
            converter.Options.RenderingEngine = renderingEngine;
            converter.Options.WebElementsMappingOptions.CssSelectors =
                TxtElements.Split(new char[] { ',' });

            // create a new pdf document converting an url
            PdfDocument doc = converter.ConvertUrl(TxtUrl);

            // get all web elements and mark/highlight them with a blue rectangle
            foreach (WebElement element in
                converter.Options.WebElementsMappingOptions.Result)
            {
                // each web element has several rendering rectangles 
                // (if it is displayed in more than 1 page)
                foreach (WebElementPdfRectangle webElementRectangle
                    in element.PdfRectangles)
                {
                    // get the PDF page
                    PdfPage page = doc.Pages[webElementRectangle.PageIndex];
                    RectangleF rectangle = webElementRectangle.Rectangle;

                    // highlight the HTML element
                    PdfRectangleElement blueRectangle = new PdfRectangleElement(
                        rectangle.X, rectangle.Y,
                        rectangle.Width, rectangle.Height);
                    blueRectangle.ForeColor = Color.Blue;

                    page.Add(blueRectangle);
                }
            }

            // save pdf document
            byte[] pdf = doc.Save();

            // close pdf document
            doc.Close();

            // return resulted pdf document
            FileResult fileResult = new FileContentResult(pdf, "application/pdf");
            fileResult.FileDownloadName = "Document.pdf";
            return fileResult;

        }
    }
}