@using Lagerbestand.Models
@using Lagerbestand.Services
@inject IStorageLocationService StorageLocationService

@if (IsOpen)
{
    <div class="picker-overlay" @onclick="Cancel">
        <div class="picker-dialog" @onclick:stopPropagation="true" role="dialog" aria-modal="true" aria-labelledby="picker-title">
            <header class="picker-header">
                <div>
                    <h2 id="picker-title">Lagerplatz wählen</h2>
                    @if (!string.IsNullOrEmpty(Subtitle))
                    {
                        <p class="picker-subtitle">@Subtitle</p>
                    }
                </div>
                <button type="button" class="picker-close" @onclick="Cancel" aria-label="Schließen">✕</button>
            </header>

            <div class="picker-body">
                @if (isLoading)
                {
                    <div class="picker-loading" role="status">Lade Lagerplätze...</div>
                }
                else
                {
                    <div class="rack-view">
                        @foreach (var area in new[] { AreaType.Werkstatt, AreaType.Lager })
                        {
                            <div class="building-section" @key="area">
                                <h3 class="building-title">@area.GetBuildingLabel()</h3>
                                @for (int row = StorageLocation.MinRow; row <= area.GetMaxRow(); row++)
                                {
                                    var currentRow = row;
                                    <div class="rack-row" @key="@($"{area}-{currentRow}")">
                                        <h4 class="row-title">Reihe @currentRow</h4>
                                        <div class="rack-sides">
                                            @foreach (var side in new[] { "Links", "Rechts" })
                                            {
                                                <div class="rack-side" @key="side">
                                                    <span class="side-label">@side</span>
                                                    @foreach (var pos in ShelfPositionExtensions.All.Where(p => p.IsLeft() == (side == "Links")).OrderByDescending(p => p.IsTop()))
                                                    {
                                                        <div class="rack-level" @key="pos">
                                                            <span class="level-label">@(pos.IsTop() ? "Oben" : "Unten")</span>
                                                            <div class="rack-cells">
                                                                @for (int slot = StorageLocation.MinSlot; slot <= StorageLocation.MaxSlot; slot++)
                                                                {
                                                                    var loc = GetLocation(area, currentRow, pos, slot);
                                                                    var isHighlighted = loc != null && HighlightLocationId == loc.Id;
                                                                    var isSelectable = loc != null && (isHighlighted || (loc.IsAvailable && !loc.IsOccupied));
                                                                    var cellClass = loc == null ? "missing" : isHighlighted ? "freeing" : !loc.IsAvailable ? "blocked" : loc.IsOccupied ? "occupied" : "free";
                                                                    <button type="button"
                                                                            class="rack-cell @cellClass @(pendingLocation?.Id == loc?.Id ? "selected" : "")"
                                                                            @key="slot"
                                                                            disabled="@(!isSelectable)"
                                                                            title="@GetTooltip(loc, area, currentRow, pos, slot, isHighlighted)"
                                                                            @onclick="() => Select(loc)">
                                                                        @slot
                                                                    </button>
                                                                }
                                                            </div>
                                                        </div>
                                                    }
                                                </div>
                                            }
                                        </div>
                                    </div>
                                }
                            </div>
                        }
                    </div>

                    <div class="rack-legend" aria-hidden="true">
                        <span class="legend-item"><span class="legend-swatch free"></span> Frei</span>
                        @if (HighlightLocationId.HasValue)
                        {
                            <span class="legend-item"><span class="legend-swatch freeing"></span> Wird frei</span>
                        }
                        <span class="legend-item"><span class="legend-swatch occupied"></span> Belegt</span>
                        <span class="legend-item"><span class="legend-swatch blocked"></span> Gesperrt</span>
                    </div>
                }
            </div>

            <footer class="picker-footer">
                <div class="picker-selection">
                    @if (pendingLocation != null)
                    {
                        <span class="picker-selection-label">Ausgewählt:</span>
                        <LocationDisplay Code="@pendingLocation.Code" DisplayMode="LocationDisplayMode.Full" Size="LocationDisplaySize.Small" />
                    }
                    else
                    {
                        <span class="picker-selection-hint">Bitte einen freien Platz anklicken</span>
                    }
                </div>
                <div class="picker-actions">
                    <button type="button" class="btn btn-outline" @onclick="Cancel">Abbrechen</button>
                    <button type="button" class="btn btn-primary" @onclick="Confirm" disabled="@(pendingLocation == null)">Übernehmen</button>
                </div>
            </footer>
        </div>
    </div>
}

@code {
    [Parameter] public bool IsOpen { get; set; }
    [Parameter] public EventCallback<bool> IsOpenChanged { get; set; }

    /// <summary>Currently selected location (pre-selected when opening).</summary>
    [Parameter] public Guid? SelectedLocationId { get; set; }

    /// <summary>Location that is about to be freed (e.g. during a swap) – shown as selectable.</summary>
    [Parameter] public Guid? HighlightLocationId { get; set; }

    [Parameter] public string? Subtitle { get; set; }

    [Parameter] public EventCallback<StorageLocation> OnSelected { get; set; }

    private bool isLoading;
    private bool wasOpen;
    private List<StorageLocation> allLocations = new();
    private Dictionary<(AreaType, int, ShelfPosition, int), StorageLocation> lookup = new();
    private StorageLocation? pendingLocation;

    protected override async Task OnParametersSetAsync()
    {
        if (IsOpen && !wasOpen)
        {
            wasOpen = true;
            await LoadAsync();
        }
        else if (!IsOpen)
        {
            wasOpen = false;
        }
    }

    private async Task LoadAsync()
    {
        isLoading = true;
        try
        {
            allLocations = await StorageLocationService.GetAllAsync();
            lookup = allLocations.ToDictionary(l => (l.Area, l.Row, l.Position, l.SlotNumber));
            pendingLocation = SelectedLocationId.HasValue
                ? allLocations.FirstOrDefault(l => l.Id == SelectedLocationId.Value)
                : null;
        }
        finally
        {
            isLoading = false;
        }
    }

    private StorageLocation? GetLocation(AreaType area, int row, ShelfPosition pos, int slot)
        => lookup.TryGetValue((area, row, pos, slot), out var loc) ? loc : null;

    private void Select(StorageLocation? loc)
    {
        if (loc == null) return;
        pendingLocation = loc;
    }

    private async Task Confirm()
    {
        if (pendingLocation == null) return;
        await OnSelected.InvokeAsync(pendingLocation);
        await Close();
    }

    private Task Cancel() => Close();

    private async Task Close()
    {
        IsOpen = false;
        await IsOpenChanged.InvokeAsync(false);
    }

    private string GetTooltip(StorageLocation? loc, AreaType area, int row, ShelfPosition pos, int slot, bool isHighlighted)
    {
        var baseText = $"{area.GetDisplayName()}, Reihe {row}, {pos.GetDisplayName()}, Platz {slot}";
        if (loc == null) return $"{baseText} – nicht angelegt";
        if (isHighlighted) return $"{baseText} – wird frei";
        if (!loc.IsAvailable) return $"{baseText} – gesperrt";
        if (loc.IsOccupied) return $"{baseText} – belegt";
        return $"{baseText} – frei";
    }
}