ersatztv/ErsatzTV/Pages/Logs.razor

@page "/system/logs"
@using System.Globalization
@using ErsatzTV.Application.Configuration
@using ErsatzTV.Application.Logs
@implements IDisposable
@inject IMediator Mediator

<MudForm Style="max-height: 100%">
    <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">Logs</MudText>
            <MudDivider Class="mb-6"/>
            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
                <div class="d-flex">
                    <MudText>Search</MudText>
                </div>
                <MudTextField T="string" ValueChanged="@(s => OnSearch(s))" Adornment="Adornment.Start"
                              AdornmentIcon="@Icons.Material.Filled.Search" IconSize="Size.Medium"/>
            </MudStack>
            <MudTable FixedHeader="true"
                      @bind-RowsPerPage="@_rowsPerPage"
                      ServerData="@(new Func<TableState, CancellationToken, Task<TableData<LogEntryViewModel>>>(ServerReload))"
                      Dense="true"
                      Class="mt-10"
                      @ref="_table">
                <HeaderContent>
                    <MudTh>
                        <MudTableSortLabel T="LogEntryViewModel" SortLabel="Timestamp">
                            Timestamp
                        </MudTableSortLabel>
                    </MudTh>
                    <MudTh>
                        <MudTableSortLabel T="LogEntryViewModel" SortLabel="Level">
                            Level
                        </MudTableSortLabel>
                    </MudTh>
                    <MudTh>Message</MudTh>
                </HeaderContent>
                <RowTemplate>
                    <MudTd>@context.Timestamp.ToString("G", _dtf)</MudTd>
                    <MudTd>@context.Level</MudTd>
                    <MudTd>@context.Message</MudTd>
                </RowTemplate>
                <NoRecordsContent>
                    <MudText>No matching records found</MudText>
                </NoRecordsContent>
                <LoadingContent>
                    <MudText>Loading...</MudText>
                </LoadingContent>
                <PagerContent>
                    <MudTablePager/>
                </PagerContent>
            </MudTable>
        </MudContainer>
    </div>
</MudForm>

@code {
    private CancellationTokenSource _cts;

    private readonly DateTimeFormatInfo _dtf = CultureInfo.CurrentUICulture.DateTimeFormat;

    private MudTable<LogEntryViewModel> _table;
    private int _rowsPerPage = 10;
    private string _searchString;

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

    protected override async Task OnParametersSetAsync()
    {
        _cts?.Cancel();
        _cts?.Dispose();
        _cts = new CancellationTokenSource();
        var token = _cts.Token;

        try
        {
            _rowsPerPage = await Mediator.Send(new GetConfigElementByKey(ConfigElementKey.LogsPageSize), token)
                .Map(maybeRows => maybeRows.Match(ce => int.TryParse(ce.Value, out int rows) ? rows : 10, () => 10));
        }
        catch (OperationCanceledException)
        {
            // do nothing
        }
    }

    private async Task<TableData<LogEntryViewModel>> ServerReload(TableState state, CancellationToken cancellationToken)
    {
        await Mediator.Send(new SaveConfigElementByKey(ConfigElementKey.LogsPageSize, state.PageSize.ToString()), cancellationToken);

        PagedLogEntriesViewModel data;

        switch (state.SortLabel?.ToLowerInvariant())
        {
            case "timestamp":
                data = await Mediator.Send(
                    new GetRecentLogEntries(state.Page, state.PageSize, _searchString)
                    {
                        SortExpression = le => le.Timestamp,
                        SortDescending = state.SortDirection == SortDirection.None
                            ? Option<bool>.None
                            : state.SortDirection == SortDirection.Descending
                    },
                    cancellationToken);
                break;
            case "level":
                data = await Mediator.Send(
                    new GetRecentLogEntries(state.Page, state.PageSize, _searchString)
                    {
                        SortExpression = le => le.Level,
                        SortDescending = state.SortDirection == SortDirection.None
                            ? Option<bool>.None
                            : state.SortDirection == SortDirection.Descending
                    },
                    cancellationToken);
                break;
            default:
                data = await Mediator.Send(
                    new GetRecentLogEntries(state.Page, state.PageSize, _searchString)
                    {
                        SortDescending = Option<bool>.None
                    },
                    cancellationToken);
                break;
        }

        return new TableData<LogEntryViewModel> { TotalItems = data.TotalCount, Items = data.Page };
    }

    private void OnSearch(string text)
    {
        _searchString = text;
        _table.ReloadServerData();
    }

}