@using NexusReader.Application.DTOs.AI
@using NexusReader.Application.Abstractions.Services
@using NexusReader.Application.DTOs.User
@using NexusReader.UI.Shared.Components.Atoms
@using NexusReader.UI.Shared.Services
@using NexusReader.UI.Shared.Models
@using System.Net.Http.Json
@namespace NexusReader.UI.Shared.Components.Organisms
@inject HttpClient Http
@inject IKnowledgeService KnowledgeService
@inject IReaderNavigationService NavigationService

<div class="global-intelligence-sheet @(IsOpen ? "is-open" : "")">
    <div class="sheet-backdrop" @onclick="HandleClose"></div>
    <div class="sheet-content">
        <div class="sheet-drag-handle"></div>
        
        <header class="sheet-header">
            <div class="header-main">
                <div class="ai-avatar-badge">
                    <NexusIcon Name="robot" Size="20" Class="neon-glow" />
                </div>
                <div class="header-info">
                    <h3>Asystent AI Nexus</h3>
                    <p class="subtitle">Zadawaj pytania do swojej biblioteki</p>
                </div>
            </div>
            <button class="close-btn" @onclick="HandleClose" aria-label="Zamknij">
                <NexusIcon Name="close" Size="20" />
            </button>
        </header>

        <div class="sheet-body">
            <div class="chat-thread" id="mobile-chat-thread">
                @if (_chatMessages.Count == 0)
                {
                    <div class="welcome-container">
                        <div class="welcome-glow-icon">
                            <NexusIcon Name="brain" Size="32" Class="neon-glow" />
                        </div>
                        <h4>Zadaj pytanie asystentowi</h4>
                        <p>KM-RAG przeszukuje całą treść książki, wyciąga semantyczne powiązania i generuje precyzyjne odpowiedzi wraz z przypisami źródłowymi.</p>
                    </div>
                }
                else
                {
                    @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")
                                {
                                    <NexusIcon Name="user" Size="16" />
                                }
                                else
                                {
                                    <NexusIcon Name="robot" Size="16" />
                                }
                            </div>
                            <div class="message-bubble @(message.Sender == "User" ? "user-bubble" : "ai-bubble")">
                                <div class="message-meta">
                                    <span class="sender-name">@(message.Sender == "User" ? "Ty" : "Asystent")</span>
                                    <span class="message-time">@message.Timestamp.ToString("HH:mm")</span>
                                </div>
                                <div class="message-text">
                                    @foreach (var segment in message.Segments)
                                    {
                                        @if (segment.IsCitation)
                                        {
                                            <span class="nexus-mobile-citation" @onclick="() => HandleCitationClick(segment.CitationId)">
                                                [@segment.CitationId]
                                            </span>
                                        }
                                        else
                                        {
                                            @RenderMarkdown(segment.Text)
                                        }
                                    }
                                </div>
                            </div>
                        </div>
                    }

                    @if (_isLoading)
                    {
                        <div class="message-row ai-row">
                            <div class="message-avatar">
                                <NexusIcon Name="robot" Size="16" />
                            </div>
                            <div class="message-bubble ai-bubble pending-bubble">
                                <div class="message-meta">
                                    <span class="sender-name">Asystent</span>
                                    <span class="message-time">Generowanie...</span>
                                </div>
                                <div class="message-text">
                                    <div class="typing-indicator">
                                        <span></span>
                                        <span></span>
                                        <span></span>
                                    </div>
                                    <span class="loading-label">Analiza grafu pojęć...</span>
                                </div>
                            </div>
                        </div>
                    }
                }
            </div>
        </div>

        <footer class="sheet-footer">
            <div class="scope-indicator">
                <NexusIcon Name="map" Size="12" />
                <span>Obszar: <strong>@(string.IsNullOrEmpty(_activeBookTitle) ? "Cała biblioteka" : _activeBookTitle)</strong></span>
            </div>
            
            <div class="input-container">
                <input type="text" 
                       class="nexus-mobile-input" 
                       placeholder="Zadaj pytanie..." 
                       @bind="_question" 
                       @bind:event="oninput"
                       @onkeyup="HandleKeyUp"
                       disabled="@_isLoading" />
                
                <button class="send-btn @(string.IsNullOrWhiteSpace(_question) || _isLoading ? "disabled" : "")" 
                        disabled="@(string.IsNullOrWhiteSpace(_question) || _isLoading)" 
                        @onclick="AskQuestionAsync">
                    @if (_isLoading)
                    {
                        <div class="btn-spinner"></div>
                    }
                    else
                    {
                        <NexusIcon Name="send" Size="18" />
                    }
                </button>
            </div>
        </footer>

        @if (_selectedCitation != null)
        {
            <div class="citation-modal-overlay" @onclick="CloseCitationModal">
                <div class="citation-modal glass-panel" @onclick:stopPropagation>
                    <div class="modal-header">
                        <span class="book-title"><NexusIcon Name="map" Size="14" /> @_selectedCitation.SourceBook</span>
                        <button class="close-btn" @onclick="CloseCitationModal" aria-label="Close">
                            <NexusIcon Name="close" Size="16" />
                        </button>
                    </div>
                    <div class="modal-body">
                        @if (!string.IsNullOrEmpty(_selectedCitation.Author))
                        {
                            <p class="citation-author"><strong>Autor:</strong> @_selectedCitation.Author</p>
                        }
                        @if (_selectedCitation.PageNumber.HasValue)
                        {
                            <p class="citation-page"><strong>Strona:</strong> @_selectedCitation.PageNumber.Value</p>
                        }
                        <p class="citation-snippet">"@_selectedCitation.Snippet"</p>
                    </div>
                    <div class="modal-footer">
                        <button class="btn-nexus" @onclick="CloseCitationModal">Zamknij</button>
                    </div>
                </div>
            </div>
        }
    </div>
</div>

@code {
    private static readonly System.Text.RegularExpressions.Regex CitationRegex = new(
        @"\[Source ID:\s*([^\]]+)\]|\[([a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12})\]", 
        System.Text.RegularExpressions.RegexOptions.IgnoreCase | System.Text.RegularExpressions.RegexOptions.Compiled);

    private static readonly System.Text.RegularExpressions.Regex BoldRegex = new(
        @"\*\*(.*?)\*\*", 
        System.Text.RegularExpressions.RegexOptions.Compiled);

    private static readonly System.Text.RegularExpressions.Regex ItalicRegex = new(
        @"\*(.*?)\*", 
        System.Text.RegularExpressions.RegexOptions.Compiled);

    private static readonly System.Text.RegularExpressions.Regex CodeBlockRegex = new(
        @"```(?:[a-zA-Z0-9+#]+)?\s*([\s\S]*?)\s*```", 
        System.Text.RegularExpressions.RegexOptions.Compiled);

    private static readonly System.Text.RegularExpressions.Regex InlineCodeRegex = new(
        @"`(.*?)`", 
        System.Text.RegularExpressions.RegexOptions.Compiled);

    [Parameter] public bool IsOpen { get; set; }
    [Parameter] public EventCallback OnClose { get; set; }
    [Parameter] public string? TenantId { get; set; }

    private string _question = string.Empty;
    private bool _isLoading;
    private string _activeBookTitle = string.Empty;
    private List<ChatMessage> _chatMessages = new();
    private CitationDto? _selectedCitation;

    protected override async Task OnParametersSetAsync()
    {
        if (IsOpen && string.IsNullOrEmpty(_activeBookTitle) && NavigationService.CurrentEbookId != Guid.Empty)
        {
            _activeBookTitle = NavigationService.ChapterTitle ?? "Aktywna książka";
        }
    }

    private async Task HandleClose()
    {
        if (OnClose.HasDelegate)
        {
            await OnClose.InvokeAsync();
        }
    }

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

    private void HandleCitationClick(string citationId)
    {
        _selectedCitation = _chatMessages
            .SelectMany(m => m.Citations)
            .FirstOrDefault(c => c.CitationId.Equals(citationId, StringComparison.OrdinalIgnoreCase))
            ?? new CitationDto
            {
                CitationId = citationId,
                SourceBook = "Grounded Document Chunk",
                Snippet = "Context snippet retrieved from vector search node."
            };
    }

    private void CloseCitationModal()
    {
        _selectedCitation = null;
    }

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

        var userQuestion = _question;
        _question = string.Empty;
        _isLoading = true;

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

        StateHasChanged();

        try
        {
            Guid? ebookId = null;
            if (NavigationService.CurrentEbookId != Guid.Empty)
            {
                ebookId = NavigationService.CurrentEbookId;
            }

            var tenantId = TenantId ?? "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 = $"Błąd: {result.Errors.FirstOrDefault()?.Message ?? "Wystąpił nieznany problem."}";
                _chatMessages.Add(new ChatMessage
                {
                    Sender = "AI",
                    Text = errMsg,
                    Segments = new List<ResponseSegment> { new ResponseSegment { Text = errMsg, IsCitation = false } }
                });
            }
        }
        catch (Exception ex)
        {
            var errMsg = $"Błąd sieci/API: {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;

        var matches = CitationRegex.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);

        var html = System.Net.WebUtility.HtmlEncode(text);
        html = BoldRegex.Replace(html, "<strong>$1</strong>");
        html = ItalicRegex.Replace(html, "<em>$1</em>");
        html = CodeBlockRegex.Replace(html, "<pre class=\"nexus-mobile-code-block\"><code>$1</code></pre>");
        html = InlineCodeRegex.Replace(html, "<code class=\"nexus-mobile-inline-code\">$1</code>");
        html = html.Replace("\n", "<br />");

        return new MarkupString(html);
    }
}