using System;
using System.Data;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.IO;
using Elwig.Helpers;
using Elwig.Helpers.Weighing;
using System.Collections.Generic;
using System.Windows.Threading;

namespace Elwig {
    public partial class App : Application {

        public static readonly string DataPath = @"C:\ProgramData\Elwig\";
        public static readonly string ExePath = @"C:\Program Files\Elwig\";
        public static readonly Config Config = new(DataPath + "config.ini");
        public static IEnumerable<IScale> Scales { get; private set; }

        public static bool IsPrintingReady => Documents.Html.IsReady && Documents.Pdf.IsReady;
        public static Dispatcher MainDispatcher { get; private set; }

        public App() : base() {
            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
            Directory.CreateDirectory(Path.Combine(Path.GetTempPath(), "Elwig"));
            Directory.CreateDirectory(DataPath);
            MainDispatcher = Dispatcher;
            Scales = Array.Empty<IScale>();
        }

        protected override void OnStartup(StartupEventArgs evt) {
            using (var ctx = new AppDbContext()) {
                if (!ctx.Database.CanConnect()) {
                    MessageBox.Show($"Invalid Database:\n\n{Config.DatabaseFile}", "Invalid Database", MessageBoxButton.OK, MessageBoxImage.Error);
                    Shutdown();
                }
            }
            Utils.RunBackground("HTML Initialization", () => Documents.Html.Init(PrintingReadyChanged));
            Utils.RunBackground("PDF Initialization", () => Documents.Pdf.Init(PrintingReadyChanged));

            var list = new LinkedList<IScale>();
            foreach (var s in Config.Scales) {
                try {
                    var scaleNr = int.Parse(s[0]);
                    var type = s[1].ToLower();
                    var model = s[2];
                    var cnx = s[3];
                    var empty = s[4];
                    var filling = s[5];
                    int? limit = s[6] == null ? null : int.Parse(s[6]);
                    if (type == "systec") {
                        list.AddLast(new SystecScale(scaleNr, model, cnx, empty, filling, limit));
                    }
                } catch (Exception e) {
                    MessageBox.Show($"Unable to create scale {s[0]}:\n\n{e.Message}", "Scale Error", MessageBoxButton.OK, MessageBoxImage.Error);
                }
            }
            Scales = list;

            base.OnStartup(evt);
        }

        protected override void OnExit(ExitEventArgs evt) {
            Utils.RunBackground("PDF Close", () => Documents.Pdf.Close());
            base.OnExit(evt);
        }

        private void PrintingReadyChanged() {
            Dispatcher.BeginInvoke(OnPrintingReadyChanged, new EventArgs());
        }

        protected void OnPrintingReadyChanged(EventArgs evt) {
            foreach (Window w in Windows) {
                foreach (var b in Utils.FindAllChildren<Button>(w).Where(b => "Print".Equals(b.Tag))) {
                    b.IsEnabled = IsPrintingReady;
                }
            }
        }
    }
}