AuthorBuddy/Components/Pages/Chat.razor

@page "/chat"
@attribute [Authorize(Roles = "Administrator,Chat")]
@inject IChatService ChatService
@inject IOllamaService OllamaService
@inject OllamaSettings Settings
@inject ISettingsService SettingsService
@inject IAuthService AuthService
@inject NavigationManager Navigation
@inject IJSRuntime JS

@rendermode InteractiveServer

<PageTitle>Chat</PageTitle>

<div class="chat-page">
    <div class="chat-header">
        <h3>Chat</h3>
        <div class="chat-header-actions">
            <button class="btn btn-sm chat-settings-toggle" @onclick="ToggleSettings">
                @(_showSettings ? "Einstellungen ausblenden" : "Einstellungen")
            </button>
            <button class="btn btn-sm" @onclick="ClearHistory" disabled="@(_messages.Count == 0)">Verlauf löschen</button>
        </div>
    </div>

    @if (_showSettings)
    {
        <div class="chat-settings">
            <div class="form-group">
                <label>System-Prompt</label>
                <textarea class="chat-settings-textarea" @bind="_systemPrompt" rows="3"></textarea>
            </div>
            <div class="form-group">
                <label for="chatTemp">Temperatur: @_temperature.ToString("F2")</label>
                <input id="chatTemp" type="range" min="0" max="2" step="0.05" @bind="_temperature" @bind:event="oninput" />
                <div class="qm-range-labels">
                    <span>präzise (0)</span>
                    <span>kreativ (2)</span>
                </div>
            </div>
            <div class="form-group">
                <button class="btn btn-sm btn-primary" @onclick="SaveSettings">System-Prompt & Temperatur speichern</button>
                <button class="btn btn-sm" @onclick="ResetToDefault">Auf Standard zurücksetzen</button>
            </div>
        </div>
    }

    <div class="chat-messages" id="chat-messages">
        @if (_messages.Count == 0)
        {
            <div class="chat-empty">Noch keine Nachrichten. Stelle eine Frage.</div>
        }
        @foreach (var msg in _messages)
        {
            <div class="chat-message chat-user">
                <div class="chat-avatar">U</div>
                <div class="chat-bubble">@msg.UserMessage</div>
            </div>
            <div class="chat-message chat-assistant">
                <div class="chat-avatar">A</div>
                <div class="chat-bubble">@MarkdownToHtml(msg.AssistantResponse)</div>
            </div>
        }
        @if (_isBusy)
        {
            <div class="chat-message chat-assistant">
                <div class="chat-avatar">A</div>
                <div class="chat-bubble chat-thinking">…</div>
            </div>
        }
    </div>

    <div class="chat-input">
                <textarea class="chat-textarea" @bind="_input" @bind:event="oninput" rows="3"
                          placeholder="Nachricht eingeben…"
                          @onkeydown="HandleKeyDown"
                          disabled="@_isBusy"></textarea>
        <button class="btn btn-primary" @onclick="Send" disabled="@_sendDisabled">
            Senden
        </button>
    </div>

    @if (!string.IsNullOrEmpty(_error))
    {
        <div class="auth-error">@_error</div>
    }
</div>

@code {
    private List<ChatEntity> _messages = new();
    private string _input = string.Empty;
    private string _error = string.Empty;
    private bool _isBusy;
    private int _userId;
    private bool _showSettings;
    private bool _sendDisabled => _isBusy || string.IsNullOrWhiteSpace(_input);
    private string _systemPrompt = string.Empty;
    private double _temperature = 0.7;
    private bool _needsScroll;

    protected override async Task OnInitializedAsync()
    {
        var user = await AuthService.GetCurrentUserAsync();
        if (user == null || (!user.HasRole(UserRole.Administrator) && !user.HasRole(UserRole.Chat)))
        {
            Navigation.NavigateTo("/");
            return;
        }
        _userId = user.Id;
        _messages = await ChatService.GetHistoryAsync(_userId);
        _systemPrompt = await SettingsService.GetChatPromptAsync()
            ?? Settings.GetChatDefaultPrompt(Settings.Language);
        _temperature = await SettingsService.GetChatTempAsync();
        _needsScroll = true;
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (_needsScroll)
        {
            _needsScroll = false;
            await ScrollToBottom();
        }
    }

    private void ToggleSettings()
    {
        _showSettings = !_showSettings;
    }

    private async Task SaveSettings()
    {
        await SettingsService.SaveChatPromptAsync(_systemPrompt);
        await SettingsService.SaveChatTempAsync(_temperature);
    }

    private async Task ResetToDefault()
    {
        _systemPrompt = Settings.GetChatDefaultPrompt(Settings.Language);
        _temperature = Settings.ChatTemp;
        await SaveSettings();
    }

    private async Task HandleKeyDown(KeyboardEventArgs e)
    {
        if (e.Key == "Enter" && !e.ShiftKey)
        {
            await Send();
        }
    }

    private async Task Send()
    {
        if (string.IsNullOrWhiteSpace(_input) || _isBusy) return;

        var text = _input.Trim();
        _input = string.Empty;
        _error = string.Empty;
        _isBusy = true;
        _needsScroll = true;

        try
        {
            var response = await OllamaService.Chat(Settings.StyleModel, text, _systemPrompt, _temperature);

            var msg = new ChatEntity
            {
                UserId = _userId,
                UserMessage = text,
                AssistantResponse = response,
                Model = Settings.StyleModel,
                Timestamp = DateTime.UtcNow
            };
            await ChatService.AddMessageAsync(msg);
            _messages.Add(msg);
            _needsScroll = true;
        }
        catch (Exception ex)
        {
            _error = $"Fehler: {ex.Message}";
        }
        finally
        {
            _isBusy = false;
            _input = string.Empty;
            _needsScroll = true;
        }
    }

    private async Task ClearHistory()
    {
        await ChatService.ClearHistoryAsync(_userId);
        _messages.Clear();
    }

    private async Task ScrollToBottom()
    {
        await JS.InvokeVoidAsync("eval", "document.getElementById('chat-messages').scrollTop = document.getElementById('chat-messages').scrollHeight");
    }

    private MarkupString MarkdownToHtml(string text)
    {
        if (string.IsNullOrEmpty(text)) return new MarkupString(string.Empty);
        var html = System.Web.HttpUtility.HtmlEncode(text);
        html = System.Text.RegularExpressions.Regex.Replace(html, @"\*\*(.+?)\*\*", "<strong>$1</strong>");
        html = System.Text.RegularExpressions.Regex.Replace(html, @"\*(.+?)\*", "<em>$1</em>");
        html = html.Replace("\n", "<br />");
        return new MarkupString(html);
    }
}