@page "/channels/{Id:int?}"
@page "/channels/add"
@using static LanguageExt.Prelude
@using ErsatzTV.Application.FFmpegProfiles
@using ErsatzTV.Application.FFmpegProfiles.Queries
@using ErsatzTV.Application.Images.Commands
@using ErsatzTV.Application.MediaItems.Queries
@using System.Globalization
@using ErsatzTV.Application.Channels
@using ErsatzTV.Application.Channels.Queries
@inject NavigationManager _navigationManager
@inject ILogger<ChannelEditor> _logger
@inject ISnackbar _snackbar
@inject IMediator _mediator

<MudContainer MaxWidth="MaxWidth.ExtraLarge" Class="pt-8">
    <div style="max-width: 400px;">
        <MudText Typo="Typo.h4" Class="mb-4">@(IsEdit ? "Edit Channel" : "Add Channel")</MudText>

        <EditForm EditContext="_editContext" OnSubmit="@HandleSubmitAsync">
            <FluentValidator/>
            <MudCard>
                <MudCardContent>
                    <MudTextField Label="Number" @bind-Value="_model.Number" For="@(() => _model.Number)" Immediate="true"/>
                    <MudTextField Class="mt-3" Label="Name" @bind-Value="_model.Name" For="@(() => _model.Name)"/>
                    <MudSelect Class="mt-3" Label="Streaming Mode" @bind-Value="_model.StreamingMode" For="@(() => _model.StreamingMode)">
                        <MudSelectItem Value="@(StreamingMode.TransportStream)">MPEG-TS</MudSelectItem>
                        <MudSelectItem Value="@(StreamingMode.HttpLiveStreamingDirect)">HLS Direct</MudSelectItem>
                    </MudSelect>
                    <MudSelect Class="mt-3" Label="FFmpeg Profile" @bind-Value="_model.FFmpegProfileId" For="@(() => _model.FFmpegProfileId)"
                               Disabled="@(_model.StreamingMode != StreamingMode.TransportStream)">
                        @foreach (FFmpegProfileViewModel profile in _ffmpegProfiles)
                        {
                            <MudSelectItem Value="@profile.Id">@profile.Name</MudSelectItem>
                        }
                    </MudSelect>
                    <MudSelect Class="mt-3" Label="Preferred Language" @bind-Value="_model.PreferredLanguageCode" For="@(() => _model.PreferredLanguageCode)">
                        <MudSelectItem Value="@((string) null)">(none)</MudSelectItem>
                        @foreach (CultureInfo culture in _availableCultures)
                        {
                            <MudSelectItem Value="@culture.ThreeLetterISOLanguageName">@culture.EnglishName</MudSelectItem>
                        }
                    </MudSelect>
                    <MudGrid Class="mt-3" Style="align-items: center" Justify="Justify.Center">
                        <MudItem xs="6">
                            <InputFile id="fileInput" OnChange="UploadLogo" hidden/>
                            @if (!string.IsNullOrWhiteSpace(_model.Logo))
                            {
                                <MudElement HtmlTag="img" src="@($"iptv/logos/{_model.Logo}")" Style="max-height: 50px"/>
                            }
                        </MudItem>
                        <MudItem xs="6">
                            <MudButton Class="ml-auto" HtmlTag="label"
                                       Variant="Variant.Filled"
                                       Color="Color.Primary"
                                       StartIcon="@Icons.Material.Filled.CloudUpload"
                                       for="fileInput">
                                Upload Logo
                            </MudButton>
                        </MudItem>
                    </MudGrid>
                </MudCardContent>
                <MudCardActions>
                    <MudButton ButtonType="ButtonType.Submit" Variant="Variant.Filled" Color="Color.Primary">
                        @(IsEdit ? "Save Changes" : "Add Channel")
                    </MudButton>
                </MudCardActions>
            </MudCard>
        </EditForm>
    </div>
</MudContainer>

@code {

    [Parameter]
    public int? Id { get; set; }

    private readonly ChannelEditViewModel _model = new();
    private EditContext _editContext;
    private ValidationMessageStore _messageStore;

    private List<FFmpegProfileViewModel> _ffmpegProfiles;
    private List<CultureInfo> _availableCultures;

    protected override async Task OnParametersSetAsync()
    {
        await LoadFFmpegProfilesAsync();
        _availableCultures = await _mediator.Send(new GetAllLanguageCodes());

        if (Id.HasValue)
        {
            Option<ChannelViewModel> maybeChannel = await _mediator.Send(new GetChannelById(Id.Value));
            maybeChannel.Match(
                channelViewModel =>
                {
                    _model.Id = channelViewModel.Id;
                    _model.Name = channelViewModel.Name;
                    _model.Number = channelViewModel.Number;
                    _model.FFmpegProfileId = channelViewModel.FFmpegProfileId;
                    _model.Logo = channelViewModel.Logo;
                    _model.StreamingMode = channelViewModel.StreamingMode;
                    _model.PreferredLanguageCode = channelViewModel.PreferredLanguageCode;
                },
                () => _navigationManager.NavigateTo("404"));
        }
        else
        {
            FFmpegSettingsViewModel ffmpegSettings = await _mediator.Send(new GetFFmpegSettings());

    // TODO: command for new channel
            IEnumerable<int> channelNumbers = await _mediator.Send(new GetAllChannels())
                .Map(list => list.Map(c => int.TryParse(c.Number.Split(".").Head(), out int result) ? result : 0));
            int maxNumber = Optional(channelNumbers).Flatten().DefaultIfEmpty(0).Max();
            _model.Number = (maxNumber + 1).ToString();
            _model.Name = "New Channel";
            _model.FFmpegProfileId = ffmpegSettings.DefaultFFmpegProfileId;
            _model.StreamingMode = StreamingMode.TransportStream;
        }
    }

    protected override void OnInitialized()
    {
        _editContext = new EditContext(_model);
        _messageStore = new ValidationMessageStore(_editContext);
    }

    private bool IsEdit => Id.HasValue;

    private async Task LoadFFmpegProfilesAsync() =>
        _ffmpegProfiles = await _mediator.Send(new GetAllFFmpegProfiles());

    private async Task HandleSubmitAsync()
    {
        _messageStore.Clear();
        if (_editContext.Validate())
        {
            Seq<BaseError> errorMessage = IsEdit ?
                (await _mediator.Send(_model.ToUpdate())).LeftToSeq() :
                (await _mediator.Send(_model.ToCreate())).LeftToSeq();

            errorMessage.HeadOrNone().Match(
                error =>
                {
                    _snackbar.Add(error.Value, Severity.Error);
                    _logger.LogError("Unexpected error saving channel: {Error}", error.Value);
                },
                () => _navigationManager.NavigateTo("/channels"));
        }
    }

    private async Task UploadLogo(InputFileChangeEventArgs e)
    {
        var buffer = new byte[e.File.Size];
        await e.File.OpenReadStream().ReadAsync(buffer);
        Either<BaseError, string> maybeCacheFileName = await _mediator.Send(new SaveArtworkToDisk(buffer, ArtworkKind.Logo));
        maybeCacheFileName.Match(
            relativeFileName =>
            {
                _model.Logo = relativeFileName;
                StateHasChanged();
            },
            error =>
            {
                _snackbar.Add($"Unexpected error saving channel logo: {error.Value}", Severity.Error);
                _logger.LogError("Unexpected error saving channel logo: {Error}", error.Value);
            });
    }

}