@page "/Calendar"
@using Template.Shared.Core.Dto
@using Template.Shared.Core.Interface
@using Template.Shared.Components.Layout
@using Template.Shared.Components.SingleElements
@using Template.Shared.Components.Layout.Spinner
@inject IManageDataService manageData
@inject IDialogService Dialog
@inject IJSRuntime JS

<HeaderLayout Title="@CurrentMonth.ToString("MMMM yyyy", new System.Globalization.CultureInfo("it-IT")).FirstCharToUpper()"
              ShowFilter="true"
              ShowCalendarToggle="true"
              OnCalendarToggle="ToggleExpanded"/>

<div @ref="weekSliderRef" class="container week-slider @(Expanded ? "expanded" : "") @(SliderAnimation)">
    @if (Expanded)
    {
        <!-- Vista mensile -->
        @foreach (var nomeGiorno in GiorniSettimana)
        {
            <div class="week-day">
                <div>@nomeGiorno</div>
            </div>
        }

        @foreach (var unused in Enumerable.Range(0, StartOffset))
        {
            <div class="day" style="visibility: hidden"></div>
        }

        @for (var d = 1; d <= DaysInMonth; d++)
        {
            var day = new DateTime(CurrentMonth.Year, CurrentMonth.Month, d);
            var isSelected = IsSameDay(day, SelectedDate);
            var isToday = IsSameDay(day, DateTime.Today);
            var events = GetEventsForDay(day);

            <div class="day @(isSelected ? "selected" : (isToday ? "today" : ""))"
                 @onclick="() => SelezionaDataDalMese(day)">
                <div>@d</div>
                @if (events.Any())
                {
                    <div class="event-dot-container" style="margin-top: 2px;">
                        @foreach (var cat in events.Select(x => x.Category).Distinct())
                        {
                            <div class="event-dot @cat.ConvertToHumanReadable()" title="@cat.ConvertToHumanReadable()"></div>
                        }
                    </div>
                }
            </div>
        }

        @foreach (var unused in Enumerable.Range(0, EndOffset))
        {
            <div class="day" style="visibility: hidden"></div>
        }
    }
    else
    {
        <!-- Vista settimanale -->
        @foreach (var day in DaysOfWeek)
        {
            var isSelected = IsSameDay(day, SelectedDate);
            var isToday = IsSameDay(day, DateTime.Today);

            <div class="week-day">
                <div>@day.ToString("ddd", new System.Globalization.CultureInfo("it-IT"))</div>
                <div class="day @(isSelected ? "selected" : (isToday ? "today" : ""))"
                     @onclick="() => SelezionaData(day)">
                    <div>@day.Day</div>
                    @if (GetEventsForDay(day).Any())
                    {
                        <div class="event-dot-container" style="margin-top: 2px;">
                            @foreach (var cat in GetEventsForDay(day).Select(x => x.Category).Distinct())
                            {
                                <div class="event-dot @cat.ConvertToHumanReadable()" title="@cat.ConvertToHumanReadable()"></div>
                            }
                        </div>
                    }
                </div>
            </div>
        }
    }
</div>

<div class="container appointments">
    @if (IsLoading)
    {
        <SpinnerLayout FullScreen="false"/>
    }
    else if (FilteredActivities is { Count: > 0 })
    {
        <Virtualize Items="FilteredActivities" Context="activity">
            <ActivityCard Activity="activity" />
        </Virtualize>
    }
    else
    {
        <NoDataAvailable Text="Nessuna attività trovata" ImageSource="_content/Template.Shared/images/undraw_file-search_cbur.svg"/>
    }
</div>

@code {

    // Stato UI
    private bool Expanded { get; set; } = false;
    private string SliderAnimation { get; set; } = string.Empty;
    private ElementReference weekSliderRef;
    private DotNetObjectReference<Calendar>? dotNetHelper;

    // Stato calendario
    private DateTime SelectedDate { get; set; } = DateTime.Today;
    private DateTime _internalMonth = DateTime.Today;
    private DateTime CurrentMonth => new(_internalMonth.Year, _internalMonth.Month, 1);

    // Stato attività
    private List<ActivityDTO> MonthActivities { get; set; } = [];
    private List<ActivityDTO> FilteredActivities { get; set; } = [];
    private bool IsLoading { get; set; } = true;

    // Supporto rendering mese
    private static readonly string[] GiorniSettimana = ["Lu", "Ma", "Me", "Gi", "Ve", "Sa", "Do"];
    private int DaysInMonth => DateTime.DaysInMonth(CurrentMonth.Year, CurrentMonth.Month);
    private int StartOffset => (int)CurrentMonth.DayOfWeek == 0 ? 6 : (int)CurrentMonth.DayOfWeek - 1;

    private int EndOffset
    {
        get
        {
            var totalCells = (int)Math.Ceiling((DaysInMonth + StartOffset) / 7.0) * 7;
            return totalCells - (DaysInMonth + StartOffset);
        }
    }

    // Supporto rendering settimana
    private IEnumerable<DateTime> DaysOfWeek
    {
        get
        {
            var start = GetStartOfWeek(SelectedDate);
            return Enumerable.Range(0, 7).Select(i => start.AddDays(i));
        }
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            dotNetHelper = DotNetObjectReference.Create(this);
            await JS.InvokeVoidAsync("calendarSwipe.register", weekSliderRef, dotNetHelper);
            _internalMonth = new DateTime(SelectedDate.Year, SelectedDate.Month, 1);
            await LoadMonthData();
        }
    }

    [JSInvokable]
    public async Task OnSwipeLeft()
    {
        await CambiaPeriodo(1);
        StateHasChanged();
        if (Expanded)
        {
            await LoadMonthData();
        }
    }

    [JSInvokable]
    public async Task OnSwipeRight()
    {
        await CambiaPeriodo(-1);
        StateHasChanged();
        if (Expanded)
        {
            await LoadMonthData();
        }
    }

    [JSInvokable]
    public async Task OnSwipeDown()
    {
        if (!Expanded)
            ToggleExpanded();
    }

    [JSInvokable]
    public async Task OnSwipeUp()
    {
        if (Expanded)
            ToggleExpanded();
    }

    // Cambio periodo mese/settimana
    private async Task CambiaPeriodo(int direzione)
    {
        if (Expanded)
        {
            // Cambio solo il mese visualizzato, NON cambiare SelectedDate
            var y = CurrentMonth.Year;
            var m = CurrentMonth.Month + direzione;
            if (m < 1)
            {
                y--;
                m = 12;
            }

            if (m > 12)
            {
                y++;
                m = 1;
            }

            _internalMonth = new DateTime(y, m, 1);
        }
        else
        {
            // Cambio settimana: aggiorno anche il giorno selezionato
            await SelezionaData(SelectedDate.AddDays(7 * direzione));
            _internalMonth = new DateTime(SelectedDate.Year, SelectedDate.Month, 1);
        }
    }

    // Cambio modalità
    private void ToggleExpanded()
    {
        if (Expanded)
        {
            SliderAnimation = "collapse-animation";
            StateHasChanged();
            Expanded = false;
        }
        else
        {
            Expanded = true;
            SliderAnimation = "expand-animation";
            StateHasChanged();
        }

        SliderAnimation = "";
        StateHasChanged();
    }

    // Caricamento attività al cambio mese
    private async Task LoadMonthData()
    {
        IsLoading = true;
        StateHasChanged();

        // Carica tutte le attività del mese corrente visualizzato
        var start = CurrentMonth;
        var end = start.AddDays(DaysInMonth - 1);
        var activities = await manageData.GetActivity(x =>
            (x.EffectiveDate == null && x.EstimatedDate >= start && x.EstimatedDate <= end) ||
            (x.EffectiveDate >= start && x.EffectiveDate <= end));
        MonthActivities = activities.OrderBy(x => x.EffectiveDate ?? x.EstimatedDate).ToList();

        IsLoading = false;
        StateHasChanged();
    }

    // Selezione giorno in settimana
    private async Task SelezionaData(DateTime day)
    {
        SelectedDate = day;
        StateHasChanged();

        var cacheInternalMonth = _internalMonth;
        _internalMonth = new DateTime(day.Year, day.Month, 1);

        if (cacheInternalMonth != _internalMonth)
        {
            await LoadMonthData();
        }

        FilteredActivities = GetEventsForDay(day);
        StateHasChanged();
    }

    // Selezione giorno dal mese (chiude la vista mese!)
    private async Task SelezionaDataDalMese(DateTime day)
    {
        SelectedDate = day;
        FilteredActivities = GetEventsForDay(day);
        // Chiudi la vista mese e passa alla settimana, con animazione
        SliderAnimation = "collapse-animation";
        StateHasChanged();
        Expanded = false;
        _internalMonth = new DateTime(day.Year, day.Month, 1); // Sync il mese visualizzato
        SliderAnimation = "";
        StateHasChanged();
    }

    // Utility
    private static bool IsSameDay(DateTime d1, DateTime d2) => d1.Date == d2.Date;

    private static DateTime GetStartOfWeek(DateTime date)
    {
        var day = date.DayOfWeek == DayOfWeek.Sunday ? 7 : (int)date.DayOfWeek;
        return date.AddDays(-day + 1).Date;
    }

    private List<ActivityDTO> GetEventsForDay(DateTime day)
        => MonthActivities?.Where(x => (x.EffectiveDate ?? x.EstimatedDate) == day.Date).ToList() ?? [];

    public void Dispose()
    {
        dotNetHelper?.Dispose();
    }
}