VideoStudy/VideoStudy.UI/Pages/Home.razor

@page "/"
@inject HttpClient Http
@inject YouTubeService YouTubeService
@inject PersistenceService PersistenceService
@inject NavigationManager NavigationManager
@using VideoStudy.Shared
@using System.Net.Http.Json
@using System.Text.Json
@using System.Threading

<PageTitle>VideoStudy</PageTitle>

<div class="container-fluid py-4">
    <header class="text-center mb-5">
        <h1 class="display-4 fw-bold" style="background: linear-gradient(135deg, #667eea 0%, #764ba2 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent;">
            VideoStudy
        </h1>
        <p class="lead text-muted">Transforme vídeos em guias de estudo com IA</p>
    </header>

    <div class="row">
        <div class="col-lg-8 mx-auto">

            <div class="card shadow-sm border-0 rounded-4 overflow-hidden mb-4 p-4 bg-white">
                <YouTubeProcessor
                    OnVideoUrlChanged="HandleVideoUrlChanged"
                    OnStart="StartAnalysis"
                    IsProcessing="@isProcessing"
                    VideoInfo="@currentVideoInfo" />

                <!-- Contexto do usuário -->
                <div class="mt-3">
                    <label class="form-label fw-bold text-muted small">
                        Contexto <span class="fw-normal">(opcional)</span>
                    </label>
                    <textarea class="form-control" rows="2"
                              placeholder="Ex: tutorial técnico de Python para iniciantes / aula escolar sobre fotossíntese / passo a passo para montar um móvel"
                              @bind="userContext" disabled="@isProcessing"></textarea>
                </div>

                <div class="row g-3 mt-1">
                    <div class="col-md-12">
                        <label class="form-label fw-bold text-muted small">Idioma de saída</label>
                        <select class="form-select" @bind="selectedLanguage" disabled="@isProcessing">
                            <option value="pt">Português (BR)</option>
                            <option value="en">English</option>
                            <option value="es">Español</option>
                            <option value="fr">Français</option>
                        </select>
                    </div>
                </div>
            </div>

            @if (isProcessing || currentStep > 0)
            {
                <ProgressIndicator Status="@statusMessage" Percent="@progress" CurrentStepIndex="@currentStep" />
            }

            @if (logs.Count > 0)
            {
                <div class="card shadow-sm mb-4 border-0 rounded-4 overflow-hidden">
                    <div class="card-header bg-dark text-white d-flex justify-content-between align-items-center"
                         style="cursor: pointer;" @onclick="ToggleLogs">
                        <small class="fw-bold">Log de execução</small>
                        <small>@logs.Count eventos @(showLogs ? "▼" : "▶")</small>
                    </div>
                    @if (showLogs)
                    {
                        <div class="card-body bg-light" style="max-height: 200px; overflow-y: auto; font-family: monospace; font-size: 0.8rem;">
                            @foreach (var log in logs)
                            {
                                <div class="text-dark border-bottom py-1">
                                    <span class="text-muted">[@log.Timestamp.ToString("HH:mm:ss")]</span> @log.Message
                                </div>
                            }
                        </div>
                    }
                </div>
            }

            @if (!string.IsNullOrEmpty(generatedPdfPath))
            {
                <PdfPreview PdfPath="@generatedPdfPath" OnCancel="@(() => generatedPdfPath = null)" />
            }

        </div>
    </div>
</div>

@code {
    private bool isProcessing = false;
    private int progress = 0;
    private int currentStep = 0;
    private string statusMessage = "Pronto";
    private bool showLogs = false;
    private List<LogEntry> logs = new();

    private string videoUrl = string.Empty;
    private string selectedLanguage = "pt";
    private string? userContext;
    private VideoInfo? currentVideoInfo;
    private string? generatedPdfPath;

    private class LogEntry
    {
        public DateTime Timestamp { get; set; } = DateTime.Now;
        public string Message { get; set; } = string.Empty;
    }

    private void ToggleLogs() => showLogs = !showLogs;

    private void AddLog(string message, int? eventProgress = null)
    {
        logs.Insert(0, new LogEntry { Message = message });
        if (logs.Count > 100) logs.RemoveAt(logs.Count - 1);
        if (eventProgress.HasValue) progress = eventProgress.Value;
        StateHasChanged();
    }

    private async Task HandleVideoUrlChanged(string url)
    {
        videoUrl = url;
        try
        {
            AddLog($"Buscando informações: {url}");
            currentVideoInfo = await YouTubeService.GetVideoInfoAsync(url);
            if (currentVideoInfo != null) AddLog($"Encontrado: {currentVideoInfo.Title}");
        }
        catch (Exception ex)
        {
            AddLog($"Erro ao buscar vídeo: {ex.Message}");
        }
    }

    private async Task StartAnalysis()
    {
        isProcessing = true;
        progress = 0;
        currentStep = 0;
        generatedPdfPath = null;
        logs.Clear();
        showLogs = true;

        CancellationTokenSource? cts = null;

        try
        {
            cts = new CancellationTokenSource();
            var token = cts.Token;

            currentStep = 1;
            statusMessage = "Iniciando análise...";
            AddLog("Enviando para o servidor...", 5);

            var request = new AnalysisRequest
            {
                VideoUrl = videoUrl,
                Mode = "fast",
                Language = "en",
                OutputLanguage = selectedLanguage,
                DurationSeconds = currentVideoInfo?.Duration.TotalSeconds ?? 0,
                UserContext = string.IsNullOrWhiteSpace(userContext) ? null : userContext.Trim()
            };

            var httpRequest = new HttpRequestMessage(HttpMethod.Post, "api/analyze")
            {
                Content = JsonContent.Create(request)
            };

            using var response = await Http.SendAsync(httpRequest, HttpCompletionOption.ResponseHeadersRead, token);
            response.EnsureSuccessStatusCode();

            var stream = response.Content.ReadFromJsonAsAsyncEnumerable<AnalysisEvent>(
                new JsonSerializerOptions { PropertyNameCaseInsensitive = true }, token);

            await foreach (var ev in stream.WithCancellation(token))
            {
                if (ev == null) continue;
                if (ev.IsError) throw new Exception(ev.Message);

                AddLog(ev.Message, ev.ProgressPercentage);
                statusMessage = ev.Message;
                StateHasChanged();

                if (ev.Result != null)
                {
                    AddLog("Análise concluída!", 100);

                    if (ev.Result.PdfData != null && ev.Result.PdfData.Length > 0)
                    {
                        AddLog("Salvando PDF na biblioteca...", 100);
                        var session = await PersistenceService.SaveSessionAsync(
                            ev.Result.PdfData,
                            ev.Result.DocumentTitle,
                            videoUrl);

                        generatedPdfPath = session.FilePath;
                        AddLog($"PDF salvo em: {session.FilePath}", 100);

                        await Task.Delay(2000);
                        NavigationManager.NavigateTo("library");
                    }
                    break;
                }
            }
        }
        catch (Exception ex)
        {
            AddLog($"Erro: {ex.Message}");
            statusMessage = "Erro na análise";
        }
        finally
        {
            isProcessing = false;
            cts?.Dispose();
        }
    }
}