import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:file_picker/file_picker.dart';
import 'package:flux/features/attachments/data/attachments_repository.dart';
import 'package:flux/features/attachments/ui/attachment_viewer_screen.dart';
import 'package:flux/features/attachments/ui/quick_rename_dialog.dart';
import 'package:flux/features/operations/blocs/operation_files_bloc.dart';
import 'package:get_it/get_it.dart';
import 'package:shared_preferences/shared_preferences.dart';
import 'package:flux/features/operations/models/operation_model.dart';
import 'package:flux/features/attachments/models/attachment_model.dart';
import 'package:pdf/widgets.dart' as pw;
import 'package:pdf/pdf.dart' as p; // Se ti serve formattazione core
import 'package:pdfx/pdfx.dart' as px; // Isoliamo pdfx

class _ExportItem {
  final Uint8List bytes;
  final String sourceName;
  final bool isMultiPage;
  final int pageIndex;

  _ExportItem({
    required this.bytes,
    required this.sourceName,
    required this.isMultiPage,
    required this.pageIndex,
  });
}

class OperationFilesSection extends StatefulWidget {
  final OperationModel currentOp;

  const OperationFilesSection({super.key, required this.currentOp});

  @override
  State<OperationFilesSection> createState() => _OperationFilesSectionState();
}

class _OperationFilesSectionState extends State<OperationFilesSection> {
  String? _exportDirectory;

  @override
  void initState() {
    super.initState();
    _loadExportDirectory();
  }

  // --- GESTIONE CARTELLA CITRIX (SOLO DESKTOP) ---
  Future<void> _loadExportDirectory() async {
    if (kIsWeb) return;
    final prefs = await SharedPreferences.getInstance();
    setState(() {
      _exportDirectory = prefs.getString('citrix_export_path');
    });
  }

  Future<void> _selectExportDirectory() async {
    final String? selectedDirectory = await FilePicker.getDirectoryPath(
      dialogTitle: 'Seleziona la cartella di esportazione per TIM/Citrix',
    );

    if (selectedDirectory != null) {
      final prefs = await SharedPreferences.getInstance();
      await prefs.setString('citrix_export_path', selectedDirectory);
      setState(() {
        _exportDirectory = selectedDirectory;
      });
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Cartella Export impostata: $selectedDirectory'),
          ),
        );
      }
    }
  }

  // --- SELEZIONE FILE DAL PC/TELEFONO ---
  Future<void> _pickFiles() async {
    final result = await FilePicker.pickFiles(
      allowMultiple: true,
      type: FileType.custom,
      allowedExtensions: ['jpg', 'jpeg', 'png', 'pdf'],
      withData: true,
    );

    if (result != null && mounted) {
      // MAGIA: Passiamo direttamente la lista di PlatformFile al tuo BLoC!
      context.read<OperationFilesBloc>().add(
        AddOperationFilesEvent(result.files),
      );
    }
  }

  // --- APERTURA VIEWER ---
  void _openFile(AttachmentModel file) {
    // 1. Catturiamo il BLoC dalla pagina corrente prima di navigare
    final operationFilesBloc = context.read<OperationFilesBloc>();
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (viewerContext) => BlocProvider.value(
          value: operationFilesBloc,
          child: AttachmentViewerScreen(
            attachment: file,
            onRename: (newName) {
              // Spara l'evento al BLoC e lui farà il resto!
              operationFilesBloc.add(RenameOperationFileEvent(file, newName));
            },
            onDelete: () {
              operationFilesBloc.add(DeleteSpecificOperationFileEvent(file));
            },
          ),
        ),
      ),
    );
  }

  Future<void> _exportMergedPdf(List<AttachmentModel> selectedFiles) async {
    if (!kIsWeb && (_exportDirectory == null || _exportDirectory!.isEmpty)) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Imposta prima la cartella Citrix!')),
      );
      return;
    }

    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => const Center(child: CircularProgressIndicator()),
    );

    try {
      // 1. "FLATTEN" DI TUTTO (Stessa magia di prima)
      List<Uint8List> allPagesAsImages = [];
      final repository = GetIt.I.get<AttachmentsRepository>();

      for (var file in selectedFiles) {
        Uint8List? fileBytes;

        if (file.localBytes != null) {
          fileBytes = file.localBytes;
        } else if (file.storagePath != null && file.storagePath!.isNotEmpty) {
          fileBytes = await repository.downloadAttachmentBytes(
            file.storagePath!,
          );
        }

        if (fileBytes == null) continue;

        if (file.extension == 'pdf') {
          final document = await px.PdfDocument.openData(fileBytes);
          for (int i = 1; i <= document.pagesCount; i++) {
            final page = await document.getPage(i);
            final pageImage = await page.render(
              width: page.width * 2,
              height: page.height * 2,
              format: px.PdfPageImageFormat.jpeg,
            );
            if (pageImage != null) {
              allPagesAsImages.add(pageImage.bytes);
            }
            await page.close();
          }
          await document.close();
        } else {
          // È un'immagine
          allPagesAsImages.add(fileBytes);
        }
      }

      if (mounted) Navigator.pop(context); // Togliamo il loading

      // Se per qualche motivo la lista è vuota, usciamo
      if (allPagesAsImages.isEmpty) return;

      // 2. LOGICA DEL NOME SUGGERITO
      String suggestedName;
      if (selectedFiles.length == 1) {
        // Se c'è un solo file (es. ho selezionato 3 foto ma poi ho deselezionato le altre)
        suggestedName = selectedFiles.first.name;
      } else {
        // Se sono più file uniti
        suggestedName = '${widget.currentOp.customerDisplayName}_Unito';
      }

      if (!mounted) return;

      // 3. DIALOG DI CONFERMA (Mostriamo la PRIMA pagina come anteprima per fargli capire cos'è)
      final finalName = await showDialog<String>(
        context: context,
        builder: (_) => QuickRenameDialog(
          suggestedName: suggestedName,
          previewWidget: Image.memory(
            allPagesAsImages.first,
            fit: BoxFit.contain,
          ),
        ),
      );

      if (finalName == null || finalName.isEmpty) return; // Ha annullato

      // 4. CREAZIONE DEL PDF UNICO (IL MERGE VERO E PROPRIO)
      final pdf = pw.Document();

      // Cicliamo su tutte le immagini estratte e creiamo una pagina per ognuna
      for (var imageBytes in allPagesAsImages) {
        final pdfImage = pw.MemoryImage(imageBytes);

        pdf.addPage(
          pw.Page(
            margin: pw.EdgeInsets.zero,
            build: (pw.Context context) {
              return pw.Center(child: pw.Image(pdfImage));
            },
          ),
        );
      }

      final mergedPdfBytes = await pdf.save();

      // 5. SALVATAGGIO SUL DISCO
      if (kIsWeb) {
        // Trigger download web
      } else {
        final fileToSave = File('$_exportDirectory/$finalName.pdf');
        await fileToSave.writeAsBytes(mergedPdfBytes);
      }

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('PDF Multi-pagina creato e salvato con successo!'),
          ),
        );
      }
    } catch (e) {
      if (mounted) {
        // Se il loading è ancora aperto, lo chiudiamo
        if (Navigator.canPop(context)) Navigator.pop(context);
        ScaffoldMessenger.of(
          context,
        ).showSnackBar(SnackBar(content: Text('Errore durante l\'unione: $e')));
      }
    }
  }

  Future<void> _exportSplitPdfs(List<AttachmentModel> selectedFiles) async {
    if (!kIsWeb && (_exportDirectory == null || _exportDirectory!.isEmpty)) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Imposta prima la cartella Citrix!')),
      );
      return;
    }

    showDialog(
      context: context,
      barrierDismissible: false,
      builder: (_) => const Center(child: CircularProgressIndicator()),
    );

    try {
      // 1. "FLATTEN" INTELLIGENTE (Ora usiamo la nostra classe _ExportItem)
      List<_ExportItem> itemsToExport = [];
      final repository = GetIt.I.get<AttachmentsRepository>();

      for (var file in selectedFiles) {
        Uint8List? fileBytes;

        if (file.localBytes != null) {
          fileBytes = file.localBytes;
        } else if (file.storagePath != null && file.storagePath!.isNotEmpty) {
          fileBytes = await repository.downloadAttachmentBytes(
            file.storagePath!,
          );
        }

        if (fileBytes == null) continue;

        // Recuperiamo il nome che l'utente ha (magari) già impostato
        final baseName = file.name ?? 'Documento';

        if (file.extension == 'pdf') {
          final document = await px.PdfDocument.openData(fileBytes);
          final isMulti =
              document.pagesCount > 1; // Controlliamo se è multipagina!

          for (int i = 1; i <= document.pagesCount; i++) {
            final page = await document.getPage(i);

            final pageImage = await page.render(
              width: page.width * 2,
              height: page.height * 2,
              format: px.PdfPageImageFormat.jpeg,
            );

            if (pageImage != null) {
              // Salviamo l'immagine CON il suo contesto storico
              itemsToExport.add(
                _ExportItem(
                  bytes: pageImage.bytes,
                  sourceName: baseName,
                  isMultiPage: isMulti,
                  pageIndex: i,
                ),
              );
            }
            await page.close();
          }
          await document.close();
        } else {
          // SE È UN'IMMAGINE, la salviamo come singola pagina
          itemsToExport.add(
            _ExportItem(
              bytes: fileBytes,
              sourceName: baseName,
              isMultiPage: false,
              pageIndex: 1,
            ),
          );
        }
      }

      if (mounted) Navigator.pop(context);

      // 2. IL CICLO UX
      for (var item in itemsToExport) {
        if (!mounted) return;

        // LA TUA MAGIA UX SUI NOMI:
        // Se è singolo (foto o PDF da 1 pag) -> Usa il nome originale nudo e crudo!
        // Se è multipagina -> Usa il nome originale + il numero di pagina
        String suggestedName = item.sourceName;
        if (item.isMultiPage) {
          suggestedName = '${item.sourceName}_Pag_${item.pageIndex}';
        }

        final finalName = await showDialog<String>(
          context: context,
          builder: (_) => QuickRenameDialog(
            suggestedName: suggestedName,
            previewWidget: Image.memory(item.bytes, fit: BoxFit.contain),
          ),
        );

        if (finalName == null || finalName.isEmpty) continue;

        // CREAZIONE DEL PDF SINGOLO
        final pdf = pw.Document();
        final pdfImage = pw.MemoryImage(item.bytes); // Usiamo item.bytes!

        pdf.addPage(
          pw.Page(
            margin: pw.EdgeInsets.zero,
            build: (pw.Context context) {
              return pw.Center(child: pw.Image(pdfImage));
            },
          ),
        );

        final singlePdfBytes = await pdf.save();

        if (kIsWeb) {
          // Trigger download web
        } else {
          final fileToSave = File('$_exportDirectory/$finalName.pdf');
          await fileToSave.writeAsBytes(singlePdfBytes);
        }
      }

      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Esportazione completata con successo!'),
          ),
        );
      }
    } catch (e) {
      if (mounted) {
        Navigator.pop(context);
        ScaffoldMessenger.of(
          context,
        ).showSnackBar(SnackBar(content: Text('Errore: $e')));
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    // USIAMO IL TUO BLOC!
    return BlocBuilder<OperationFilesBloc, OperationFilesState>(
      builder: (context, state) {
        final allFiles = state.allFiles;
        final selectedFiles = state.selectedFiles;
        final hasSelection = selectedFiles.isNotEmpty;

        return Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 1. SETTINGS CARTELLA (Solo visibile su Desktop)
            if (!kIsWeb)
              Card(
                color: theme.colorScheme.surfaceContainerHighest.withValues(
                  alpha: 0.5,
                ),
                elevation: 0,
                margin: const EdgeInsets.only(bottom: 16),
                child: ListTile(
                  leading: Icon(
                    Icons.folder_special,
                    color: theme.colorScheme.primary,
                  ),
                  title: const Text(
                    'Cartella Export (Es. Citrix TIM)',
                    style: TextStyle(fontWeight: FontWeight.bold),
                  ),
                  subtitle: Text(
                    _exportDirectory ??
                        'Nessuna cartella selezionata. Clicca per impostare.',
                    style: TextStyle(
                      color: _exportDirectory == null
                          ? theme.colorScheme.error
                          : null,
                    ),
                  ),
                  trailing: const Icon(Icons.settings),
                  onTap: _selectExportDirectory,
                ),
              ),

            // 2. ACTION BAR DINAMICA
            Wrap(
              crossAxisAlignment: WrapCrossAlignment.center,
              spacing: 8,
              runSpacing: 8,
              children: [
                // Bottone di Aggiunta
                ElevatedButton.icon(
                  icon: const Icon(Icons.add_photo_alternate),
                  label: const Text('Aggiungi File'),
                  onPressed: state.status == OperationFilesStatus.uploading
                      ? null
                      : _pickFiles,
                ),
                const SizedBox(width: 12),

                // NUOVO: SELEZIONA / DESELEZIONA TUTTO
                if (allFiles.isNotEmpty) ...[
                  TextButton.icon(
                    icon: Icon(
                      selectedFiles.length == allFiles.length
                          ? Icons.deselect
                          : Icons.select_all,
                    ),
                    label: Text(
                      selectedFiles.length == allFiles.length
                          ? 'Deseleziona Tutto'
                          : 'Seleziona Tutto',
                    ),
                    onPressed: () {
                      if (selectedFiles.length == allFiles.length) {
                        context.read<OperationFilesBloc>().add(
                          ClearOperationFileSelectionEvent(),
                        );
                      } else {
                        context.read<OperationFilesBloc>().add(
                          SelectAllOperationFilesEvent(),
                        );
                      }
                    },
                  ),
                ],
                const SizedBox(width: 12),

                // Loader di upload
                if (state.status == OperationFilesStatus.uploading)
                  const SizedBox(
                    width: 24,
                    height: 24,
                    child: CircularProgressIndicator(strokeWidth: 2),
                  ),

                const Spacer(),

                // Azioni visibili SOLO se c'è una selezione!
                if (hasSelection) ...[
                  // Bottone Elimina
                  IconButton(
                    icon: const Icon(Icons.delete, color: Colors.red),
                    tooltip: 'Elimina selezionati',
                    onPressed: () {
                      context.read<OperationFilesBloc>().add(
                        DeleteOperationFilesEvent(),
                      );
                    },
                  ),
                  // Bottone Associa a Cliente
                  if (widget.currentOp.customerId != null &&
                      widget.currentOp.customerId!.isNotEmpty)
                    IconButton(
                      icon: const Icon(Icons.person_add, color: Colors.blue),
                      tooltip: 'Copia nei documenti del Cliente',
                      onPressed: () {
                        context.read<OperationFilesBloc>().add(
                          LinkFilesToCustomerEvent(
                            customerId: widget.currentOp.customerId!,
                          ),
                        );
                        ScaffoldMessenger.of(context).showSnackBar(
                          const SnackBar(
                            content: Text('File copiati nella scheda cliente!'),
                          ),
                        );
                      },
                    ),
                  // IL NUOVO BOTTONE ESPORTA CON MENU A TENDINA
                  PopupMenuButton<String>(
                    tooltip: 'Opzioni di esportazione',
                    position: PopupMenuPosition
                        .under, // Opzionale: fa aprire il menu sotto al bottone
                    onSelected: (value) {
                      if (value == 'merge') {
                        _exportMergedPdf(selectedFiles);
                      } else if (value == 'split') {
                        _exportSplitPdfs(selectedFiles);
                      }
                    },
                    itemBuilder: (BuildContext context) =>
                        <PopupMenuEntry<String>>[
                          const PopupMenuItem<String>(
                            value: 'merge',
                            child: ListTile(
                              leading: Icon(
                                Icons.merge_type,
                                color: Colors.blue,
                              ),
                              title: Text('Unisci in un singolo PDF'),
                            ),
                          ),
                          const PopupMenuItem<String>(
                            value: 'split',
                            child: ListTile(
                              leading: Icon(
                                Icons.splitscreen,
                                color: Colors.orange,
                              ),
                              title: Text(
                                'Dividi: un PDF per ogni pagina/foto',
                              ),
                            ),
                          ),
                        ],
                    // IL FIX È QUI SOTTO: AbsorbPointer + onPressed vuoto
                    child: AbsorbPointer(
                      child: FilledButton.icon(
                        style: FilledButton.styleFrom(
                          backgroundColor: Colors.red,
                        ),
                        icon: const Icon(Icons.picture_as_pdf),
                        label: Text('Esporta (${selectedFiles.length})'),
                        onPressed: () {}, // Manteniamo vivo il colore!
                      ),
                    ),
                  ),
                ],
              ],
            ),
            const SizedBox(height: 16),

            // 3. GRIGLIA DEI FILE
            if (allFiles.isEmpty)
              Container(
                width: double.infinity,
                padding: const EdgeInsets.all(32),
                decoration: BoxDecoration(
                  border: Border.all(
                    color: theme.dividerColor,
                    style: BorderStyle.solid,
                  ),
                  borderRadius: BorderRadius.circular(8),
                ),
                child: const Column(
                  children: [
                    Icon(Icons.upload_file, size: 48, color: Colors.grey),
                    SizedBox(height: 8),
                    Text(
                      'Nessun file allegato. Usa il pulsante per aggiungere documenti o foto.',
                      textAlign: TextAlign.center,
                      style: TextStyle(color: Colors.grey),
                    ),
                  ],
                ),
              )
            else
              GridView.builder(
                shrinkWrap: true,
                physics: const NeverScrollableScrollPhysics(),
                gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
                  maxCrossAxisExtent: 150,
                  crossAxisSpacing: 12,
                  mainAxisSpacing: 12,
                  childAspectRatio: 0.8,
                ),
                itemCount: allFiles.length,
                itemBuilder: (context, index) {
                  final file = allFiles[index];
                  final isPdf = file.extension == 'pdf';
                  final isSelected = selectedFiles.contains(file);
                  final isLocal =
                      file.localBytes !=
                      null; // Per capire se è un file in bozza

                  return Stack(
                    children: [
                      // CARD DEL FILE
                      InkWell(
                        onTap: () => _openFile(file),
                        onLongPress: () {
                          // Selezione rapida con long press!
                          context.read<OperationFilesBloc>().add(
                            ToggleOperationFileSelectionEvent(file),
                          );
                        },
                        borderRadius: BorderRadius.circular(8),
                        child: Container(
                          decoration: BoxDecoration(
                            border: Border.all(
                              color: isSelected
                                  ? theme.colorScheme.primary
                                  : theme.dividerColor,
                              width: isSelected ? 3 : 1,
                            ),
                            borderRadius: BorderRadius.circular(8),
                          ),
                          child: Column(
                            crossAxisAlignment: CrossAxisAlignment.stretch,
                            children: [
                              // Anteprima
                              Expanded(
                                child: Container(
                                  decoration: BoxDecoration(
                                    color: theme
                                        .colorScheme
                                        .surfaceContainerHighest,
                                    borderRadius: const BorderRadius.vertical(
                                      top: Radius.circular(8),
                                    ),
                                  ),
                                  child: isPdf
                                      ? const Icon(
                                          Icons.picture_as_pdf,
                                          size: 48,
                                          color: Colors.red,
                                        )
                                      : isLocal
                                      ? ClipRRect(
                                          borderRadius:
                                              const BorderRadius.vertical(
                                                top: Radius.circular(8),
                                              ),
                                          child: Image.memory(
                                            file.localBytes!,
                                            fit: BoxFit.cover,
                                          ),
                                        )
                                      : const Icon(
                                          Icons.image,
                                          size: 48,
                                          color: Colors.blue,
                                        ), // Da remoto metterai il tuo NetworkImage se vuoi
                                ),
                              ),
                              // Nome File
                              Padding(
                                padding: const EdgeInsets.all(8.0),
                                child: Text(
                                  file.name,
                                  maxLines: 2,
                                  overflow: TextOverflow.ellipsis,
                                  style: const TextStyle(fontSize: 12),
                                  textAlign: TextAlign.center,
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),

                      // CHECKBOX DI SELEZIONE
                      Positioned(
                        top: 4,
                        right: 4,
                        child: InkWell(
                          onTap: () {
                            context.read<OperationFilesBloc>().add(
                              ToggleOperationFileSelectionEvent(file),
                            );
                          },
                          child: Container(
                            decoration: BoxDecoration(
                              color: isSelected
                                  ? theme.colorScheme.primary
                                  : Colors.white.withValues(alpha: 0.8),
                              shape: BoxShape.circle,
                              border: Border.all(
                                color: theme.colorScheme.primary,
                              ),
                            ),
                            child: Padding(
                              padding: const EdgeInsets.all(4.0),
                              child: Icon(
                                isSelected ? Icons.check : Icons.circle,
                                size: 16,
                                color: isSelected
                                    ? Colors.white
                                    : Colors.transparent,
                              ),
                            ),
                          ),
                        ),
                      ),

                      // BADGE "IN ATTESA" (Se è locale ma la pratica è salvata)
                      if (isLocal)
                        Positioned(
                          top: 4,
                          left: 4,
                          child: Container(
                            padding: const EdgeInsets.symmetric(
                              horizontal: 6,
                              vertical: 2,
                            ),
                            decoration: BoxDecoration(
                              color: Colors.orange,
                              borderRadius: BorderRadius.circular(4),
                            ),
                            child: const Text(
                              'Bozza',
                              style: TextStyle(
                                color: Colors.white,
                                fontSize: 10,
                                fontWeight: FontWeight.bold,
                              ),
                            ),
                          ),
                        ),
                    ],
                  );
                },
              ),
          ],
        );
      },
    );
  }
}