@page "/channels/numbers"
@using ErsatzTV.Application.Channels
@implements IDisposable
@inject IMediator Mediator
@inject NavigationManager NavigationManager
@inject ISnackbar Snackbar
@inject ILogger<ChannelNumbers> Logger

<MudForm Style="max-height: 100%">
    <MudPaper Square="true" Style="display: flex; height: 64px; min-height: 64px; width: 100%; z-index: 100; align-items: center">
        <div style="display: flex; flex-direction: row; margin-bottom: auto; margin-top: auto; width: 100%; align-items: center" class="ml-6 mr-6">
            <div class="d-none d-md-flex">
                <MudButton Variant="Variant.Filled" Color="Color.Primary" StartIcon="@Icons.Material.Filled.Save" OnClick="@SaveChannels">
                    Save Channels
                </MudButton>
                <MudButton Variant="Variant.Filled" Color="Color.Error" Class="ml-3" StartIcon="@Icons.Material.Filled.Undo" OnClick="@ReloadAllChannels">
                    Reset Channels
                </MudButton>
            </div>
            <div style="align-items: center; display: flex; margin-left: auto;" class="d-md-none">
                <div class="flex-grow-1"></div>
                <MudMenu Icon="@Icons.Material.Filled.MoreVert">
                    <MudMenuItem Icon="@Icons.Material.Filled.Save" Label="Save Channels" OnClick="@SaveChannels"/>
                    <MudMenuItem Icon="@Icons.Material.Filled.Undo" Label="Reset Channels" OnClick="@ReloadAllChannels"/>
                </MudMenu>
            </div>
        </div>
    </MudPaper>
    <div class="d-flex flex-column" style="height: 100vh; overflow-x: auto">
        <MudContainer MaxWidth="MaxWidth.ExtraLarge" Class="pt-8">
            <MudText Typo="Typo.h5" Class="mb-2">Edit Channel Numbers</MudText>
            <MudDivider Class="mb-6"/>
            <Sortable TItem="ChannelSortViewModel" Items="_channels" OnUpdate="OnUpdate">
                <MudPaper Class="@($"pa-2 ma-2 ")"
                          Style="@($"max-width: 500px; {(context.HasChanged ? "background-color: var(--mud-palette-dark-lighten)" : "")}")">
                    <div class="d-flex align-center">
                        <MudText Style="min-width: 6ch">@context.Number</MudText>

                        <MudText Class="flex-grow-1">
                            @context.Name
                        </MudText>

                        <MudText Style="@(context.HasChanged ? "" : "visibility: hidden;")">
                            (@context.OriginalNumber)
                        </MudText>
                    </div>
                </MudPaper>
            </Sortable>
        </MudContainer>
    </div>
</MudForm>

@code {
    private CancellationTokenSource _cts;
    private List<ChannelSortViewModel> _channels = [];
    private List<string> _channelNumbers = [];

    public void Dispose()
    {
        _cts?.Cancel();
        _cts?.Dispose();
    }

    protected override async Task OnParametersSetAsync()
    {
        await ReloadAllChannels();
    }

    private async Task ReloadAllChannels()
    {
        _cts?.Cancel();
        _cts?.Dispose();
        _cts = new CancellationTokenSource();
        var token = _cts.Token;

        try
        {
            _channels = await Mediator.Send(new GetAllChannelsForSort(), token);
            _channelNumbers = _channels.Map(c => c.Number).ToList();
        }
        catch (OperationCanceledException)
        {
            // do nothing
        }
    }

    private async Task SaveChannels()
    {
        var changedChannels = _channels.Where(c => c.HasChanged).ToList();
        Option<BaseError> maybeError = await Mediator.Send(new UpdateChannelNumbers(changedChannels), _cts.Token);
        maybeError.Match(
            error =>
            {
                Snackbar.Add(error.Value, Severity.Error);
                Logger.LogError("Unexpected error saving channel numbers: {Error}", error.Value);
            },
            () => NavigationManager.NavigateTo("channels"));
    }

    private void OnUpdate(SortableEventArgs<ChannelSortViewModel> obj)
    {
        for (var i = 0; i < _channels.Count; i++)
        {
            _channels[i].Number = _channelNumbers[i];
        }

        StateHasChanged();
    }
}