@page "/intelligence"
@attribute [Authorize]
@using NexusReader.Application.DTOs.AI
@using NexusReader.Application.Abstractions.Services
@using NexusReader.Application.DTOs.User
@using NexusReader.UI.Shared.Components.Atoms
@using System.Net.Http.Json
@inject HttpClient Http
@inject IKnowledgeService KnowledgeService
@inject AuthenticationStateProvider AuthStateProvider

<div class="intelligence-page">
    <header class="intelligence-header">
        <div class="header-title-section">
            <h1 class="neon-glow-text">Global Intelligence</h1>
            <p class="subtitle">Interrogate, explore, and synthesize grounded knowledge from your library using Polyglot KM-RAG</p>
        </div>
    </header>

    <div class="intelligence-layout glass-panel">
        <div class="chat-thread-container">
            @if (_chatMessages.Count == 0)
            {
                <div class="welcome-state">
                    <div class="welcome-icon">
                        <svg width="64" height="64" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round">
                            <path d="M21 15a2 2 0 0 1-2 2H7l-4 4V5a2 2 0 0 1 2-2h14a2 2 0 0 1 2 2z"></path>
                        </svg>
                    </div>
                    <h3>Start Interrogating Your Library</h3>
                    <p>Ask complex questions across your entire ebook collection. The KM-RAG engine dynamically builds semantic maps, resolves dependencies, and formulates high-fidelity, grounded answers with interactive popover citations.</p>
                </div>
            }
            else
            {
                <div class="chat-bubbles-scroll">
                    @foreach (var message in _chatMessages)
                    {
                        <div class="message-row @(message.Sender == "User" ? "user-row" : "ai-row")" key="@message.Id">
                            <div class="message-avatar">
                                @if (message.Sender == "User")
                                {
                                    <i class="bi bi-person-fill"></i>
                                }
                                else
                                {
                                    <i class="bi bi-robot"></i>
                                }
                            </div>
                            <div class="message-bubble @(message.Sender == "User" ? "user-bubble" : "ai-bubble")">
                                <div class="message-header">
                                    <span class="sender-name">@message.Sender</span>
                                    <span class="message-time">@message.Timestamp.ToString("HH:mm")</span>
                                </div>
                                <div class="message-content">
                                    @foreach (var segment in message.Segments)
                                    {
                                        @if (segment.IsCitation)
                                        {
                                            <NexusCitationMarker SourceId="@segment.CitationId" Citations="@message.Citations" />
                                        }
                                        else
                                        {
                                            @RenderMarkdown(segment.Text)
                                        }
                                    }
                                </div>
                            </div>
                        </div>
                    }

                    @if (_isLoading)
                    {
                        <div class="message-row ai-row">
                            <div class="message-avatar">
                                <i class="bi bi-robot"></i>
                            </div>
                            <div class="message-bubble ai-bubble pending-bubble">
                                <div class="message-header">
                                    <span class="sender-name">AI</span>
                                    <span class="message-time">Thinking...</span>
                                </div>
                                <div class="message-content">
                                    <div class="typing-indicator">
                                        <span></span>
                                        <span></span>
                                        <span></span>
                                    </div>
                                    <span class="loading-label">Analyzing conceptual graphs and synthesizing response...</span>
                                </div>
                            </div>
                        </div>
                    }
                </div>
            }
        </div>

        <div class="chat-input-controls">
            <div class="input-panel-wrapper">
                <div class="scope-bar">
                    <div class="scope-selector">
                        <label for="book-select"><i class="bi bi-compass"></i> Scope:</label>
                        <select id="book-select" class="nexus-select" @bind="_selectedBookId">
                            <option value="">All Books (Global Search)</option>
                            @if (_books != null)
                            {
                                @foreach (var book in _books)
                                {
                                    <option value="@book.Id">@book.Title</option>
                                }
                            }
                        </select>
                    </div>
                </div>

                <div class="input-field-group">
                    <input class="nexus-input" 
                           placeholder="Ask a question about your books..." 
                           @bind="_question" 
                           @bind:event="oninput"
                           @onkeyup="HandleKeyUp"
                           disabled="@_isLoading" />
                    <button class="btn-nexus btn-nexus-primary search-btn" 
                            disabled="@(string.IsNullOrWhiteSpace(_question) || _isLoading)" 
                            @onclick="AskQuestionAsync">
                        @if (_isLoading)
                        {
                            <div class="btn-spinner"></div>
                        }
                        else
                        {
                            <span><i class="bi bi-send-fill"></i></span>
                        }
                    </button>
                </div>
            </div>
        </div>
    </div>
</div>

@code {
    private string _question = string.Empty;
    private string _selectedBookId = string.Empty;
    private bool _isLoading;
    private List<LastReadBookDto>? _books;
    private List<ChatMessage> _chatMessages = new();

    public class ChatMessage
    {
        public string Id { get; set; } = Guid.NewGuid().ToString();
        public string Sender { get; set; } = string.Empty; // "User" or "AI"
        public string Text { get; set; } = string.Empty;
        public DateTime Timestamp { get; set; } = DateTime.UtcNow;
        public List<ResponseSegment> Segments { get; set; } = new();
        public List<CitationDto> Citations { get; set; } = new();
    }

    public class ResponseSegment
    {
        public string Text { get; set; } = string.Empty;
        public bool IsCitation { get; set; }
        public string CitationId { get; set; } = string.Empty;
    }

    protected override async Task OnInitializedAsync()
    {
        try
        {
            _books = await Http.GetFromJsonAsync<List<LastReadBookDto>>("api/library/books");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[Intelligence] Failed to load books for scope selector: {ex.Message}");
        }
    }

    private async Task HandleKeyUp(KeyboardEventArgs e)
    {
        if (e.Key == "Enter" && !string.IsNullOrWhiteSpace(_question) && !_isLoading)
        {
            await AskQuestionAsync();
        }
    }

    private async Task AskQuestionAsync()
    {
        if (string.IsNullOrWhiteSpace(_question) || _isLoading) return;

        var userQuestion = _question;
        _question = string.Empty; // Clear input field immediately
        _isLoading = true;

        // Add user query message
        _chatMessages.Add(new ChatMessage
        {
            Sender = "User",
            Text = userQuestion,
            Segments = new List<ResponseSegment> { new ResponseSegment { Text = userQuestion, IsCitation = false } }
        });
        
        StateHasChanged();

        try
        {
            Guid? ebookId = null;
            if (!string.IsNullOrEmpty(_selectedBookId) && Guid.TryParse(_selectedBookId, out var parsedId))
            {
                ebookId = parsedId;
            }

            var authState = await AuthStateProvider.GetAuthenticationStateAsync();
            var tenantId = authState.User.FindFirst("TenantId")?.Value ?? "global";

            var result = await KnowledgeService.AskQuestionAsync(userQuestion, tenantId, ebookId);
            if (result.IsSuccess)
            {
                var response = result.Value;
                _chatMessages.Add(new ChatMessage
                {
                    Sender = "AI",
                    Text = response.Answer,
                    Segments = ParseSegments(response.Answer),
                    Citations = response.Citations
                });
            }
            else
            {
                var errMsg = $"Error: {result.Errors.FirstOrDefault()?.Message ?? "An error occurred."}";
                _chatMessages.Add(new ChatMessage
                {
                    Sender = "AI",
                    Text = errMsg,
                    Segments = new List<ResponseSegment> { new ResponseSegment { Text = errMsg, IsCitation = false } }
                });
            }
        }
        catch (Exception ex)
        {
            var errMsg = $"Network/API Error: {ex.Message}";
            _chatMessages.Add(new ChatMessage
            {
                Sender = "AI",
                Text = errMsg,
                Segments = new List<ResponseSegment> { new ResponseSegment { Text = errMsg, IsCitation = false } }
            });
        }
        finally
        {
            _isLoading = false;
            StateHasChanged();
        }
    }

    private List<ResponseSegment> ParseSegments(string text)
    {
        var segments = new List<ResponseSegment>();
        if (string.IsNullOrEmpty(text)) return segments;

        // Matches [Source ID: some-id] OR raw GUIDs in brackets [e225e58f-7539-cd51-e0ab-82741ec7e65c]
        var regex = new System.Text.RegularExpressions.Regex(
            @"\[Source ID:\s*([^\]]+)\]|\[([a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12})\]", 
            System.Text.RegularExpressions.RegexOptions.IgnoreCase);
        var matches = regex.Matches(text);

        int lastIndex = 0;
        foreach (System.Text.RegularExpressions.Match match in matches)
        {
            if (match.Index > lastIndex)
            {
                segments.Add(new ResponseSegment
                {
                    Text = text.Substring(lastIndex, match.Index - lastIndex),
                    IsCitation = false
                });
            }

            var citationId = match.Groups[1].Success 
                ? match.Groups[1].Value.Trim() 
                : match.Groups[2].Value.Trim();

            segments.Add(new ResponseSegment
            {
                IsCitation = true,
                CitationId = citationId
            });

            lastIndex = match.Index + match.Length;
        }

        if (lastIndex < text.Length)
        {
            segments.Add(new ResponseSegment
            {
                Text = text.Substring(lastIndex),
                IsCitation = false
            });
        }

        return segments;
    }

    private MarkupString RenderMarkdown(string text)
    {
        if (string.IsNullOrEmpty(text)) return new MarkupString(string.Empty);

        // 1. HTML Encode to prevent XSS
        var html = System.Net.WebUtility.HtmlEncode(text);

        // 2. Bold: **text** -> <strong>text</strong>
        html = System.Text.RegularExpressions.Regex.Replace(html, @"\*\*(.*?)\*\*", "<strong>$1</strong>");

        // 3. Italic: *text* -> <em>text</em>
        html = System.Text.RegularExpressions.Regex.Replace(html, @"\*(.*?)\*", "<em>$1</em>");

        // 4. Code blocks: ```language ... ``` -> <pre class="nexus-code-block"><code>...</code></pre>
        html = System.Text.RegularExpressions.Regex.Replace(html, @"```(?:[a-zA-Z0-9+#]+)?\s*([\s\S]*?)\s*```", "<pre class=\"nexus-code-block\"><code>$1</code></pre>");

        // 5. Inline Code: `code` -> <code class="nexus-inline-code">code</code>
        html = System.Text.RegularExpressions.Regex.Replace(html, @"`(.*?)`", "<code class=\"nexus-inline-code\">$1</code>");

        // 6. Newlines: \n -> <br />
        html = html.Replace("\n", "<br />");

        return new MarkupString(html);
    }
}