using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Reflection.Metadata.Ecma335;
using System.Text;
using System.Threading.Tasks;
using PdfSharp.Pdf.IO;
using PuppeteerSharp;
using PuppeteerSharp.Media;
using RazorLight;
using WGneu.Windows;

namespace WGneu.Documents {
    public static class Pdf {

        private static readonly string CHROMIUM = @"C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe";
        private static IBrowser? Browser = null;
        public static bool IsReady => Browser != null;

        public static async Task Init(Action evtHandler) {
            Browser = await Puppeteer.LaunchAsync(new LaunchOptions {
                Headless = true,
                ExecutablePath = CHROMIUM,
            });
            evtHandler();
        }

        public static async Task Convert(string path_html, string path_pdf) {
            if (Browser == null) throw new InvalidOperationException("The puppeteer engine has not been initialized yet");
            using var page = await Browser.NewPageAsync();
            await page.GoToAsync("file://" + path_html);
            await page.WaitForFunctionAsync("() => window.finished");
            await page.PdfAsync(path_pdf, new() {
                PreferCSSPageSize = true,
                //Format = PaperFormat.A4,
                DisplayHeaderFooter = false,
                MarginOptions = new() {
                    Top = "0mm",
                    Right = "0mm",
                    Bottom = "0mm",
                    Left = "0mm",
                },
            });
        }

        public static void UpdateMetadata(string path, string title, string author) {
            using var doc = PdfReader.Open(path);
            doc.Info.Title = title;
            doc.Info.Author = author;
            doc.Save(path);
        }

        public static void Show(string path, string title) {
            var w = new DocumentViewerWindow(title, path);
            w.Show();
        }

        public static void Print(string path) {
            // TODO print pdf
        }
    }
}