import 'dart:convert';
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 '../../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({super.key, required this.task});

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

class _TaskDetailsSheetState extends ConsumerState<TaskDetailsSheet> {
  final TextEditingController _commentController = TextEditingController();
  final List<String> _imagesBase64 = [];
  bool _isSubmitting = false;

  Future<void> _pickImage() async {
    if (_imagesBase64.length >= 3) {
      ScaffoldMessenger.of(context).showSnackBar(const SnackBar(content: Text('Maximum 3 images allowed')));
      return;
    }
    final ImagePicker picker = ImagePicker();
    final XFile? image = await picker.pickImage(source: ImageSource.gallery, imageQuality: 50);
    if (image != null) {
      final bytes = await image.readAsBytes();
      setState(() {
        _imagesBase64.add(base64Encode(bytes));
      });
    }
  }

  Future<void> _submitComment() async {
    if (_commentController.text.trim().isEmpty && _imagesBase64.isEmpty) return;

    setState(() => _isSubmitting = true);
    try {
      final repo = ref.read(projectRepositoryProvider);
      await repo.addComment(
        taskId: widget.task.id,
        content: _commentController.text.trim(),
        imagesBase64: _imagesBase64,
      );
      _commentController.clear();
      setState(() {
        _imagesBase64.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);
    }
  }

  @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 img = entry.value;
                                  return GestureDetector(
                                    onTap: () {
                                      final allImages = c.images.map((i) => MemoryImage(base64Decode(i)) as ImageProvider).toList();
                                      Navigator.push(
                                        context,
                                        MaterialPageRoute(
                                          builder: (context) => AttachmentGalleryScreen(
                                            images: allImages,
                                            initialIndex: imgIndex,
                                          ),
                                        ),
                                      );
                                    },
                                    child: ClipRRect(
                                      borderRadius: BorderRadius.circular(8),
                                      child: Image.memory(
                                        base64Decode(img),
                                        width: 80,
                                        height: 80,
                                        fit: BoxFit.cover,
                                      ),
                                    ),
                                  );
                                }).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 (_imagesBase64.isNotEmpty)
            Padding(
              padding: const EdgeInsets.only(bottom: 8.0),
              child: Wrap(
                spacing: 8,
                children: _imagesBase64.asMap().entries.map((entry) {
                  return Stack(
                    children: [
                      ClipRRect(
                        borderRadius: BorderRadius.circular(8),
                        child: Image.memory(
                          base64Decode(entry.value),
                          width: 60,
                          height: 60,
                          fit: BoxFit.cover,
                        ),
                      ),
                      Positioned(
                        right: 0,
                        top: 0,
                        child: GestureDetector(
                          onTap: () {
                            setState(() {
                              _imagesBase64.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,
              ),
              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,
                    ),
            ],
          ),
        ],
      ),
    );
  }
}