using Microsoft.EntityFrameworkCore;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using Elwig.Helpers;
using Elwig.Models;
using System.Runtime.CompilerServices;
using System;

namespace Elwig.Windows {
    public partial class AreaCommAdminWindow : Window {
        private readonly AppDbContext Context = new();
        private readonly Member member;
        private bool IsEditing = false;
        private bool IsCreating = false;
        private IEnumerable<TextBox> TextBoxInputs = Array.Empty<TextBox>();
        private IEnumerable<ComboBox> ComboBoxInputs = Array.Empty<ComboBox>();
        private readonly Dictionary<Control, bool> Valid = new();
        private readonly Dictionary<Control, object?> OriginalValues = new();

        public AreaCommAdminWindow(Member member) {
            InitializeComponent();
            this.member = member;
            this.Title = $"Flächenbindungen von {member.FamilyName} {member.GivenName} - Elwig";
            RefreshAreaCommitmentList();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e) {
            KgInput.ItemsSource = Context.WbKgs.Select(k => k.Kg).OrderBy(k => k.Name).ToList();
            RdInput.ItemsSource = Context.WbRde.OrderBy(r => r.Name).ToList();
        }

        private void RefreshAreaCommitmentList() {
            Context.AreaCommitments.Load();
            List<AreaCommitment> commitments = Context.AreaCommitments.Where(a => a.Contract.MgNr == member.MgNr).ToList();

            AreaCommitmentList.ItemsSource = commitments;
            if (commitments.Count == 1)
                AreaCommitmentList.SelectedIndex = 0;
        }

        private void RefreshInputs(bool validate = false) {
            ClearInputStates();
            AreaCommitment a = (AreaCommitment)AreaCommitmentList.SelectedItem;
            if (a != null) {
                //EditMemberButton.IsEnabled = true;
                //DeleteMemberButton.IsEnabled = true;
                //AreaCommitmentButton.IsEnabled = true;
                FillInputs(a);
            } else {
                //EditMemberButton.IsEnabled = false;
                //DeleteMemberButton.IsEnabled = false;
                //AreaCommitmentButton.IsEnabled = false;
                ClearInputs();
            }
            //if (!validate) ClearInputStates();
            GC.Collect();
        }

        private void FillInputs(AreaCommitment a) {
            OriginalValues.Clear();

            KgInput.SelectedItem = a.Kg.Kg;
            RdInput.SelectedItem = a.Rd;
            GstNr.Text = a.GstNr;

            FillOriginalValues();
        }

        private void FillOriginalValues() {
            foreach (var tb in TextBoxInputs)
                OriginalValues[tb] = tb.Text;
            foreach (var cb in ComboBoxInputs)
                OriginalValues[cb] = cb.SelectedItem;
        }

        private void ClearInputStates() {
            foreach (var tb in TextBoxInputs)
                Utils.ClearInputState(tb);
            foreach (var cb in ComboBoxInputs)
                Utils.ClearInputState(cb);
        }

        private void ClearInputs() {
            OriginalValues.Clear();
            foreach (var tb in TextBoxInputs) {
                tb.Text = " ";
                tb.Text = "";
            }
            foreach (var cb in ComboBoxInputs) {
                cb.SelectedItem = null;
                if (cb.ItemsSource != null)
                    Utils.SetInputInvalid(cb);
            }
        }

        private void NewAreaCommitmentButton_Click(object sender, RoutedEventArgs evt) {
            IsCreating = true;
            AreaCommitmentList.IsEnabled = false;
            AreaCommitmentList.SelectedItem = null;
            HideNewEditDeleteButtons();
            ShowSaveResetCancelButtons();
            UnlockInputs();
            InitInputs();
        }

        private void EditAreaCommitmentButton_Click(object sender, RoutedEventArgs evt) {
            if (AreaCommitmentList.SelectedItem == null)
                return;

            IsEditing = true;
            AreaCommitmentList.IsEnabled = false;

            HideNewEditDeleteButtons();
            ShowSaveResetCancelButtons();
            UnlockInputs();
        }

        private void DeleteAreaCommitmentButton_Click(object sender, RoutedEventArgs evt) {
            AreaCommitment a = (AreaCommitment)AreaCommitmentList.SelectedItem;
            if (a == null) return;

            var r = MessageBox.Show(
                $"Soll die Flächenbindung \"{a.Kg.Kg.Name}, {a.Rd.Name}\", (MgNr. {a.GstNr}) wirklich unwiderruflich gelöscht werden?",
                "Mitglied löschen", MessageBoxButton.YesNo, MessageBoxImage.Warning, MessageBoxResult.No);
            if (r == MessageBoxResult.Yes) {
                Context.Remove(a);
                Context.SaveChanges();
                RefreshAreaCommitmentList();
            }
        }

        private void SaveButton_Click(object sender, RoutedEventArgs evt) {
            AreaCommitment? a = new();
            if (IsEditing)
                a = (AreaCommitment)AreaCommitmentList.SelectedItem;
            else if (IsCreating)
                a = new();

            a.KgNr = ((AT_Kg)KgInput.SelectedItem).KgNr;
            a.RdNr = ((WbRd)RdInput.SelectedItem).RdNr;
            a.GstNr = GstNr.Text;

            try {
                if (IsEditing)
                    Context.Update(a);
                else if (IsCreating)
                    Context.Add(a);
                Context.SaveChanges();
            } catch (Exception exc) {
                var str = "Der Eintrag konnte nicht in der Datenbank aktualisiert werden!\n\n" + exc.Message;
                if (exc.InnerException != null) str += "\n\n" + exc.InnerException.Message;
                MessageBox.Show(str, "Flächenbindung aktualisieren", MessageBoxButton.OK, MessageBoxImage.Error);
            }

            IsEditing = false;
            IsCreating = false;
            AreaCommitmentList.IsEnabled = true;
            HideSaveResetCancelButtons();
            ShowNewEditDeleteButtons();
            LockInputs();
            RefreshAreaCommitmentList();
        }

        private void ResetButton_Click(object sender, RoutedEventArgs evt) {
            if (IsEditing) {
                RefreshInputs();
            } else if (IsCreating) {
                InitInputs();
            }
            UpdateButtons();
        }

        private void CancelButton_Click(object sender, RoutedEventArgs evt) {
            IsEditing = false;
            IsCreating = false;
            AreaCommitmentList.IsEnabled = true;
            HideSaveResetCancelButtons();
            ShowNewEditDeleteButtons();
            RefreshInputs();
            ClearInputStates();
            LockInputs();
        }

        private void LockInputs() {
            foreach (var tb in TextBoxInputs)
                tb.IsReadOnly = true;
            foreach (var cb in ComboBoxInputs)
                cb.IsEnabled = false;
        }

        private void UnlockInputs() {
            foreach (var tb in TextBoxInputs)
                tb.IsReadOnly = false;
            foreach (var cb in ComboBoxInputs)
                cb.IsEnabled = true;
        }

        private void UpdateButtons() {
            if (!IsEditing && !IsCreating) return;
            bool ch = HasChanged(), v = IsValid();
            ResetButton.IsEnabled = (ch);
            SaveButton.IsEnabled = (v && ch);
        }

        private void InitInputs() {
            FillOriginalValues();
        }

        private bool HasChanged() {
            return !IsValid() ||
                TextBoxInputs.Any(InputHasChanged) ||
                ComboBoxInputs.Any(InputHasChanged);
        }

        private bool InputHasChanged(Control input) {
            if (!OriginalValues.ContainsKey(input)) {
                return false;
            } else if (input is TextBox tb) {
                return OriginalValues[tb]?.ToString() != tb.Text;
            } else if (input is ComboBox sb) {
                return OriginalValues[sb] != sb.SelectedItem;
            } else {
                return false;
            }
        }

        private bool IsValid() {
            return Valid.All(kv => kv.Value) && ComboBoxInputs.All(cb => cb.ItemsSource == null || cb.SelectedItem != null);
        }

        private void ShowSaveResetCancelButtons() {
            SaveButton.IsEnabled = false;
            ResetButton.IsEnabled = false;
            CancelButton.IsEnabled = true;
            SaveButton.Visibility = Visibility.Visible;
            ResetButton.Visibility = Visibility.Visible;
            CancelButton.Visibility = Visibility.Visible;
        }

        private void HideSaveResetCancelButtons() {
            SaveButton.IsEnabled = false;
            ResetButton.IsEnabled = false;
            CancelButton.IsEnabled = false;
            SaveButton.Visibility = Visibility.Hidden;
            ResetButton.Visibility = Visibility.Hidden;
            CancelButton.Visibility = Visibility.Hidden;
        }

        private void ShowNewEditDeleteButtons() {
            NewAreaCommitmentButton.IsEnabled = true;
            EditAreaCommitmentButton.IsEnabled = AreaCommitmentList.SelectedItem != null;
            DeleteAreaCommitmentButton.IsEnabled = AreaCommitmentList.SelectedItem != null;
            NewAreaCommitmentButton.Visibility = Visibility.Visible;
            EditAreaCommitmentButton.Visibility = Visibility.Visible;
            DeleteAreaCommitmentButton.Visibility = Visibility.Visible;
        }

        private void HideNewEditDeleteButtons() {
            NewAreaCommitmentButton.IsEnabled = false;
            EditAreaCommitmentButton.IsEnabled = false;
            DeleteAreaCommitmentButton.IsEnabled = false;
            NewAreaCommitmentButton.Visibility = Visibility.Hidden;
            EditAreaCommitmentButton.Visibility = Visibility.Hidden;
            DeleteAreaCommitmentButton.Visibility = Visibility.Hidden;
        }

        private void AreaCommitmentList_SelectionChanged(object sender, SelectionChangedEventArgs evt) {
            RefreshInputs();
        }
    }
}