using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using LehrerApp.Core.Interfaces;
using LehrerApp.Core.Models;
using LehrerApp.Core.Services;
using LehrerApp.Data;
using LehrerApp.Desktop.Services;
using LehrerApp.Desktop.ViewModels.Planning;
using LehrerApp.Sync;
using LehrerApp.Sync.Crypto;
using System.Collections.ObjectModel;
using System.Globalization;
using System.Security.Cryptography;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace LehrerApp.Desktop.ViewModels.Settings;

public partial class SettingsViewModel
{
    // ── Aufsichten: wiederkehrende Pausenaufsicht (4.3 Nachtrag) ─────────────

    [ObservableProperty] private string _newDutyWeekdayName = WeekdayDisplay.Options[0];
    [ObservableProperty] private int _newDutyAfterPeriod;
    [ObservableProperty] private string _newDutyLocation = "";
    [ObservableProperty] private string _newDutyError = "";

    public string[] WeekdayOptions { get; } = WeekdayDisplay.Options;
    public ObservableCollection<SupervisionDutyItem> SupervisionDuties { get; } = [];

    // ── Aufsichten: Laden / Hinzufügen / Löschen ─────────────────────────────

    private void LoadSupervisionDuties()
    {
        SupervisionDuties.Clear();
        foreach (var d in _supervisionDuties.GetAll())
            SupervisionDuties.Add(new SupervisionDutyItem(d));
    }

    [RelayCommand]
    private void AddSupervisionDuty()
    {
        NewDutyError = "";
        if (string.IsNullOrWhiteSpace(NewDutyLocation)) { NewDutyError = "Ort/Bezeichnung erforderlich."; return; }
        if (NewDutyAfterPeriod is < 0 or > 10) { NewDutyError = "Muss zwischen 0 und 10 liegen."; return; }

        try
        {
            _supervisionDuties.Save(new SupervisionDuty
            {
                Weekday = WeekdayDisplay.FromLabel(NewDutyWeekdayName),
                AfterPeriod = NewDutyAfterPeriod,
                Location = NewDutyLocation.Trim(),
            });
        }
        catch (InvalidOperationException ex) { NewDutyError = ex.Message; return; }

        NewDutyLocation = ""; NewDutyAfterPeriod = 0;
        LoadSupervisionDuties();
    }

    [RelayCommand]
    private void RemoveSupervisionDuty(SupervisionDutyItem? item)
    {
        if (item is null) return;
        _supervisionDuties.Delete(item.Id);
        SupervisionDuties.Remove(item);
    }
}

public class SupervisionDutyItem(SupervisionDuty d)
{
    public Guid   Id           { get; } = d.Id;
    public string WeekdayLabel { get; } = WeekdayDisplay.Label(d.Weekday);
    public int    AfterPeriod  { get; } = d.AfterPeriod;
    public string PeriodLabel  { get; } = d.AfterPeriod == 0 ? "Vor der 1. Stunde" : $"Nach der {d.AfterPeriod}. Stunde";
    public string Location     { get; } = d.Location;
}

// ── Wochentag: deutsche Anzeige (Mo–Fr, für Aufsichten) ────────────────────────

public static class WeekdayDisplay
{
    private static readonly (DayOfWeek Day, string Name)[] Entries =
    [
        (DayOfWeek.Monday, "Montag"), (DayOfWeek.Tuesday, "Dienstag"), (DayOfWeek.Wednesday, "Mittwoch"),
        (DayOfWeek.Thursday, "Donnerstag"), (DayOfWeek.Friday, "Freitag"),
    ];

    public static string[] Options { get; } = Entries.Select(e => e.Name).ToArray();
    public static string Label(DayOfWeek d) => Entries.First(e => e.Day == d).Name;
    public static DayOfWeek FromLabel(string label) => Entries.FirstOrDefault(e => e.Name == label).Day;
}