import 'dart:convert';
import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:lucide_icons/lucide_icons.dart';
import 'package:image_picker/image_picker.dart';
import 'package:file_picker/file_picker.dart';
import 'package:path_provider/path_provider.dart';
import 'package:dio/dio.dart';
import 'package:share_plus/share_plus.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import '../../domain/project_task.dart';
import '../../providers/project_provider.dart';
import '../../../transactions/presentation/widgets/attachment_gallery_screen.dart';

class TaskDetailsSheet extends ConsumerStatefulWidget {
  final ProjectTask task;
  const TaskDetailsSheet({Key? key, required this.task}) : super(key: key);

  @override
  ConsumerState<TaskDetailsSheet> createState() => _TaskDetailsSheetState();
}

class _TaskDetailsSheetState extends ConsumerState<TaskDetailsSheet> {
  final TextEditingController _commentController = TextEditingController();
  final ImagePicker _picker = ImagePicker();
  final List<Map<String, String>> _attachments = [];
  bool _isSubmitting = false;
  String? _jwtToken;
  final Set<int> _downloadingIds = {};

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

  Future<void> _loadToken() async {
    const storage = FlutterSecureStorage();
    _jwtToken = await storage.read(key: 'jwt_token');
    if (mounted) setState(() {});
  }

  Future<void> _pickImage() async {
    final XFile? image = await _picker.pickImage(source: ImageSource.gallery);
    if (image != null) {
      final bytes = await image.readAsBytes();
      setState(() {
        _attachments.add({
          'fileName': image.name,
          'contentType': 'image/jpeg',
          'base64Content': base64Encode(bytes),
        });
      });
    }
  }

  Future<void> _pickFile() async {
    FilePickerResult? result = await FilePicker.platform.pickFiles();
    if (result != null && result.files.single.path != null) {
      final file = File(result.files.single.path!);
      final bytes = await file.readAsBytes();
      final extension = result.files.single.extension?.toLowerCase() ?? '';
      String contentType = 'application/octet-stream';
      if (['pdf'].contains(extension)) contentType = 'application/pdf';
      else if (['doc', 'docx'].contains(extension)) contentType = 'application/msword';
      else if (['png', 'jpg', 'jpeg'].contains(extension)) contentType = 'image/jpeg';
      
      setState(() {
        _attachments.add({
          'fileName': result.files.single.name,
          'contentType': contentType,
          'base64Content': base64Encode(bytes),
        });
      });
    }
  }

  Future<void> _submitComment() async {
    if (_commentController.text.trim().isEmpty && _attachments.isEmpty) return;

    setState(() => _isSubmitting = true);
    try {
      final repo = ref.read(projectRepositoryProvider);
      await repo.addComment(
        taskId: widget.task.id,
        content: _commentController.text.trim(),
        attachments: _attachments,
      );
      _commentController.clear();
      setState(() {
        _attachments.clear();
      });
      ref.invalidate(projectTaskCommentsProvider(widget.task.id));
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Error adding comment: $e')));
      }
    } finally {
      if (mounted) setState(() => _isSubmitting = false);
    }
  }

  Future<void> _downloadAttachment(Map<String, dynamic> attMap, int commentId, int attIndex) async {
    final filePath = attMap['filePath'];
    final fileName = attMap['fileName'] ?? 'attachment';
    final contentType = attMap['contentType'] ?? 'application/octet-stream';
    if (filePath == null) return;
    
    final uniqueId = commentId * 1000 + attIndex;
    setState(() => _downloadingIds.add(uniqueId));
    
    try {
      final dir = await getTemporaryDirectory();
      final savePath = '${dir.path}/$fileName';
      final dio = Dio();
      if (_jwtToken != null) {
        dio.options.headers['Authorization'] = 'Bearer $_jwtToken';
      }
      final url = 'https://app.technobeesolutions.in/api/kifi/projects/tasks/attachments/download?filePath=$filePath&contentType=$contentType';
      await dio.download(url, savePath);
      
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Downloaded $fileName')));
        await Share.shareXFiles([XFile(savePath)]);
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Error downloading: $e')));
      }
    } finally {
      if (mounted) {
        setState(() => _downloadingIds.remove(uniqueId));
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final commentsAsync = ref.watch(projectTaskCommentsProvider(widget.task.id));

    return Container(
      height: MediaQuery.of(context).size.height * 0.9,
      decoration: const BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.vertical(top: Radius.circular(24)),
      ),
      child: Column(
        children: [
          _buildHeader(context),
          Expanded(
            child: commentsAsync.when(
              data: (comments) {
                if (comments.isEmpty) return const Center(child: Text('No comments yet.'));
                return ListView.builder(
                  padding: const EdgeInsets.all(16),
                  itemCount: comments.length,
                  itemBuilder: (context, index) {
                    final c = comments[index];
                    return Card(
                      margin: const EdgeInsets.only(bottom: 12),
                      color: Colors.grey[100],
                      elevation: 0,
                      child: Padding(
                        padding: const EdgeInsets.all(12),
                        child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          children: [
                            Text(c.content, style: const TextStyle(fontSize: 14)),
                            if (c.images.isNotEmpty) ...[
                              const SizedBox(height: 8),
                              Wrap(
                                spacing: 8,
                                children: c.images.asMap().entries.map((entry) {
                                  final imgIndex = entry.key;
                                  final imgData = entry.value;
                                  
                                  bool isOldBase64 = !imgData.startsWith('{');
                                  Map<String, dynamic>? parsedData;
                                  if (!isOldBase64) {
                                    try {
                                      parsedData = jsonDecode(imgData);
                                    } catch (_) {
                                      isOldBase64 = true;
                                    }
                                  }

                                  final isImage = isOldBase64 || (parsedData?['contentType']?.startsWith('image/') ?? false);
                                  
                                  if (isImage) {
                                    ImageProvider provider;
                                    if (isOldBase64 || parsedData?['base64Content'] != null) {
                                       final b64 = isOldBase64 ? imgData : parsedData!['base64Content'];
                                       provider = MemoryImage(base64Decode(b64));
                                    } else {
                                       final url = 'https://app.technobeesolutions.in/api/kifi/projects/tasks/attachments/download?filePath=${parsedData!['filePath']}&contentType=${parsedData['contentType']}';
                                       provider = _jwtToken != null 
                                          ? NetworkImage(url, headers: {'Authorization': 'Bearer $_jwtToken'})
                                          : const AssetImage('assets/images/placeholder.png') as ImageProvider;
                                    }

                                    return GestureDetector(
                                      onTap: () {
                                        // Collect all images for the gallery
                                        final allImages = c.images.where((i) {
                                            if (!i.startsWith('{')) return true;
                                            try {
                                                final map = jsonDecode(i);
                                                return map['contentType']?.startsWith('image/') ?? false;
                                            } catch (_) {
                                                return true;
                                            }
                                        }).map((i) {
                                            if (!i.startsWith('{')) return MemoryImage(base64Decode(i)) as ImageProvider;
                                            final map = jsonDecode(i);
                                            if (map['base64Content'] != null) return MemoryImage(base64Decode(map['base64Content'])) as ImageProvider;
                                            final url = 'https://app.technobeesolutions.in/api/kifi/projects/tasks/attachments/download?filePath=${map['filePath']}&contentType=${map['contentType']}';
                                            return NetworkImage(url, headers: {'Authorization': 'Bearer $_jwtToken'}) as ImageProvider;
                                        }).toList();
                                        
                                        // Find index of clicked image among images
                                        int realIndex = 0;
                                        for (int i=0; i<=imgIndex; i++) {
                                            final ii = c.images[i];
                                            bool img = !ii.startsWith('{');
                                            if (!img) {
                                                try {
                                                    final m = jsonDecode(ii);
                                                    img = m['contentType']?.startsWith('image/') ?? false;
                                                } catch(_) { img = true; }
                                            }
                                            if (img && i < imgIndex) realIndex++;
                                        }

                                        Navigator.push(
                                          context,
                                          MaterialPageRoute(
                                            builder: (context) => AttachmentGalleryScreen(
                                              images: allImages,
                                              initialIndex: realIndex,
                                            ),
                                          ),
                                        );
                                      },
                                      child: ClipRRect(
                                        borderRadius: BorderRadius.circular(8),
                                        child: Image(
                                          image: provider,
                                          width: 80,
                                          height: 80,
                                          fit: BoxFit.cover,
                                        ),
                                      ),
                                    );
                                  } else {
                                    // Non-image file
                                    final fileName = parsedData?['fileName'] ?? 'Document';
                                    final uniqueId = c.id * 1000 + imgIndex;
                                    final isDownloading = _downloadingIds.contains(uniqueId);
                                    
                                    return GestureDetector(
                                      onTap: () {
                                        if (!isDownloading && parsedData != null) {
                                           _downloadAttachment(parsedData, c.id, imgIndex);
                                        }
                                      },
                                      child: Container(
                                        width: 80,
                                        height: 80,
                                        decoration: BoxDecoration(
                                          color: Colors.white,
                                          borderRadius: BorderRadius.circular(8),
                                          border: Border.all(color: Colors.grey.shade300),
                                        ),
                                        child: Column(
                                          mainAxisAlignment: MainAxisAlignment.center,
                                          children: [
                                            isDownloading
                                                ? const SizedBox(width: 24, height: 24, child: CircularProgressIndicator(strokeWidth: 2))
                                                : const Icon(LucideIcons.fileText, color: Colors.blue),
                                            const SizedBox(height: 4),
                                            Padding(
                                              padding: const EdgeInsets.symmetric(horizontal: 4),
                                              child: Text(
                                                fileName,
                                                style: const TextStyle(fontSize: 10),
                                                maxLines: 1,
                                                overflow: TextOverflow.ellipsis,
                                              ),
                                            ),
                                          ],
                                        ),
                                      ),
                                    );
                                  }
                                }).toList(),
                              )
                            ]
                          ],
                        ),
                      ),
                    );
                  },
                );
              },
              loading: () => const Center(child: CircularProgressIndicator()),
              error: (err, stack) => Center(child: Text('Error: $err')),
            ),
          ),
          _buildCommentInput(),
        ],
      ),
    );
  }

  Widget _buildHeader(BuildContext context) {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(border: Border(bottom: BorderSide(color: Colors.grey.shade300))),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(widget.task.title, style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
                if (widget.task.description != null && widget.task.description!.isNotEmpty)
                  Text(widget.task.description!, style: const TextStyle(color: Colors.grey)),
              ],
            ),
          ),
          IconButton(icon: const Icon(LucideIcons.x), onPressed: () => Navigator.pop(context)),
        ],
      ),
    );
  }

  Widget _buildCommentInput() {
    return Container(
      padding: EdgeInsets.only(
        bottom: MediaQuery.of(context).viewInsets.bottom + 16,
        left: 16,
        right: 16,
        top: 16,
      ),
      decoration: BoxDecoration(
        color: Colors.white,
        border: Border(top: BorderSide(color: Colors.grey.shade300)),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          if (_attachments.isNotEmpty)
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Wrap(
                spacing: 8,
                children: _attachments.asMap().entries.map((entry) {
                  final att = entry.value;
                  final isImg = att['contentType']?.startsWith('image/') ?? false;
                  
                  return Stack(
                    children: [
                      Container(
                        width: 60,
                        height: 60,
                        decoration: BoxDecoration(
                          color: Colors.grey.shade200,
                          borderRadius: BorderRadius.circular(8),
                        ),
                        child: isImg 
                          ? ClipRRect(
                              borderRadius: BorderRadius.circular(8),
                              child: Image.memory(
                                base64Decode(att['base64Content']!),
                                fit: BoxFit.cover,
                              ),
                            )
                          : Column(
                              mainAxisAlignment: MainAxisAlignment.center,
                              children: [
                                const Icon(LucideIcons.fileText, size: 24, color: Colors.blue),
                                Text(att['fileName'] ?? '', style: const TextStyle(fontSize: 8), maxLines: 1, overflow: TextOverflow.ellipsis),
                              ],
                            ),
                      ),
                      Positioned(
                        right: 0,
                        top: 0,
                        child: GestureDetector(
                          onTap: () {
                            setState(() {
                              _attachments.removeAt(entry.key);
                            });
                          },
                          child: Container(
                            color: Colors.black54,
                            child: const Icon(LucideIcons.x, size: 16, color: Colors.white),
                          ),
                        ),
                      ),
                    ],
                  );
                }).toList(),
              ),
            ),
          Row(
            children: [
              IconButton(
                icon: const Icon(LucideIcons.image),
                onPressed: _pickImage,
              ),
              IconButton(
                icon: const Icon(LucideIcons.paperclip),
                onPressed: _pickFile,
              ),
              Expanded(
                child: TextField(
                  controller: _commentController,
                  decoration: const InputDecoration(
                    hintText: 'Add a comment...',
                    border: InputBorder.none,
                  ),
                ),
              ),
              _isSubmitting
                  ? const Padding(padding: EdgeInsets.all(12.0), child: SizedBox(width: 20, height: 20, child: CircularProgressIndicator(strokeWidth: 2)))
                  : IconButton(
                      icon: const Icon(LucideIcons.send, color: Colors.blue),
                      onPressed: _submitComment,
                    ),
            ],
          ),
        ],
      ),
    );
  }
}