import 'dart:io';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:supabase_flutter/supabase_flutter.dart';
import '../constants/item_categories.dart';
import '../theme/app_theme.dart';

class AddItemScreen extends StatefulWidget {
  const AddItemScreen({super.key});

  @override
  State<AddItemScreen> createState() => _AddItemScreenState();
}

class _AddItemScreenState extends State<AddItemScreen> {
  final _nameController = TextEditingController();
  final _descController = TextEditingController();
  final _imagePicker = ImagePicker();

  XFile? _pickedImage;
  ItemCategory? _selectedCategory;
  Subcategory? _selectedSubcategory;
  final Set<String> _selectedTags = {};
  bool _isLoading = false;

  @override
  void dispose() {
    _nameController.dispose();
    _descController.dispose();
    super.dispose();
  }

  Future<void> _pickImage() async {
    try {
      final image = await _imagePicker.pickImage(
        source: ImageSource.gallery,
        maxWidth: 1080,
        maxHeight: 1080,
        imageQuality: 80,
      );
      if (image != null) {
        setState(() => _pickedImage = image);
      }
    } catch (e) {
      if (mounted) AppSnack.error(context, 'Erro ao selecionar foto: $e');
    }
  }

  Future<void> _takePhoto() async {
    try {
      final image = await _imagePicker.pickImage(
        source: ImageSource.camera,
        maxWidth: 1080,
        maxHeight: 1080,
        imageQuality: 80,
      );
      if (image != null) {
        setState(() => _pickedImage = image);
      }
    } catch (e) {
      if (mounted) AppSnack.error(context, 'Erro ao abrir câmara: $e');
    }
  }

  void _toggleSubcategoryTags(
    Subcategory? oldSub,
    Subcategory? newSub,
  ) {
    if (oldSub != null && _selectedCategory != null) {
      for (final t in getAutoContextTags(_selectedCategory!.id, oldSub.id)) {
        _selectedTags.remove(t);
      }
    }
    if (newSub != null && _selectedCategory != null) {
      _selectedTags.addAll(
        getAutoContextTags(_selectedCategory!.id, newSub.id),
      );
    }
  }

  Future<void> _saveItem() async {
    if (_nameController.text.trim().isEmpty) {
      AppSnack.error(context, 'Indique um nome');
      return;
    }
    if (_selectedCategory == null) {
      AppSnack.error(context, 'Selecione uma categoria');
      return;
    }

    setState(() => _isLoading = true);
    try {
      final user = Supabase.instance.client.auth.currentUser;
      if (user == null) {
        AppSnack.error(context, 'Utilizador não autenticado');
        return;
      }

      await Supabase.instance.client.from('users').upsert({
        'id': user.id,
        'nome': user.userMetadata?['username'] ??
            user.email?.split('@').first ??
            'Utilizador',
      }, onConflict: 'id');

      final inserted = await Supabase.instance.client
          .from('items')
          .insert({
            'user_id': user.id,
            'nome': _nameController.text.trim(),
            'categoria': _selectedCategory!.id,
            'tags': [
              if (_selectedSubcategory != null) _selectedSubcategory!.id,
              ..._selectedTags,
            ],
          })
          .select()
          .single();
      final itemId = inserted['id'];

      if (_pickedImage != null) {
        final file = File(_pickedImage!.path);
        final fileName =
            'item_${itemId}_${DateTime.now().millisecondsSinceEpoch}.jpg';
        await Supabase.instance.client.storage
            .from('avatars')
            .upload(fileName, file);
        final imageUrl = Supabase.instance.client.storage
            .from('avatars')
            .getPublicUrl(fileName);
        await Supabase.instance.client.from('item_images').insert({
          'item_id': itemId,
          'image_url': imageUrl,
        });
      }

      if (mounted) {
        AppSnack.success(context, 'Item adicionado!');
        Navigator.pop(context);
      }
    } catch (e) {
      if (mounted) AppSnack.error(context, 'Erro ao guardar: $e');
    } finally {
      if (mounted) setState(() => _isLoading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppColors.background,
      appBar: AppBar(
        backgroundColor: AppColors.background,
        elevation: 0,
        iconTheme: const IconThemeData(color: AppColors.textPrimary),
        title: const Text('Adicionar Item', style: AppText.h3),
      ),
      body: SingleChildScrollView(
        padding: const EdgeInsets.fromLTRB(20, 8, 20, 32),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            _buildImagePicker(),
            const SizedBox(height: 24),
            const Text('Nome', style: AppText.label),
            const SizedBox(height: 8),
            _textField(
              controller: _nameController,
              hint: 'ex: Camisa azul',
              icon: Icons.label_outline_rounded,
            ),
            const SizedBox(height: 20),
            const Text('Descrição (opcional)', style: AppText.label),
            const SizedBox(height: 8),
            _textField(
              controller: _descController,
              hint: 'detalhes do item',
              icon: Icons.notes_rounded,
              maxLines: 3,
            ),
            const SizedBox(height: 24),
            const Text('Categoria', style: AppText.label),
            const SizedBox(height: 12),
            _buildCategoryGrid(),
            if (_selectedCategory != null &&
                _selectedCategory!.subcategories.isNotEmpty) ...[
              const SizedBox(height: 24),
              const Text('Subcategoria', style: AppText.label),
              const SizedBox(height: 8),
              Wrap(
                spacing: 8,
                runSpacing: 8,
                children: _selectedCategory!.subcategories.map((sub) {
                  final selected = _selectedSubcategory?.id == sub.id;
                  return AppChip(
                    label: sub.name,
                    selected: selected,
                    color: _selectedCategory!.color,
                    onTap: () {
                      setState(() {
                        final oldSub = _selectedSubcategory;
                        _selectedSubcategory = selected ? null : sub;
                        _toggleSubcategoryTags(
                          oldSub,
                          _selectedSubcategory,
                        );
                      });
                    },
                  );
                }).toList(),
              ),
              if (_selectedSubcategory != null) ...[
                const SizedBox(height: 6),
                Text(
                  _selectedSubcategory!.description,
                  style: AppText.caption.copyWith(
                    fontStyle: FontStyle.italic,
                  ),
                ),
              ],
            ],
            const SizedBox(height: 24),
            const Text('Tags de Contexto', style: AppText.label),
            const SizedBox(height: 8),
            Wrap(
              spacing: 8,
              runSpacing: 8,
              children: contextTags.map((tag) {
                final selected = _selectedTags.contains(tag.id);
                return AppChip(
                  label: tag.name,
                  selected: selected,
                  onTap: () {
                    setState(() {
                      if (selected) {
                        _selectedTags.remove(tag.id);
                      } else {
                        _selectedTags.add(tag.id);
                      }
                    });
                  },
                );
              }).toList(),
            ),
            const SizedBox(height: 32),
            AppButton(
              label: 'Guardar Item',
              icon: Icons.check_rounded,
              loading: _isLoading,
              onPressed: _saveItem,
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildImagePicker() {
    return Container(
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: BorderRadius.circular(AppRadius.lg),
        border: Border.all(color: AppColors.border),
      ),
      clipBehavior: Clip.antiAlias,
      child: Column(
        children: [
          AspectRatio(
            aspectRatio: 16 / 11,
            child: _pickedImage != null
                ? Stack(
                    fit: StackFit.expand,
                    children: [
                      Image.file(File(_pickedImage!.path), fit: BoxFit.cover),
                      Positioned(
                        top: 8,
                        right: 8,
                        child: Material(
                          color: Colors.black.withValues(alpha: 0.55),
                          shape: const CircleBorder(),
                          child: InkWell(
                            customBorder: const CircleBorder(),
                            onTap: () => setState(() => _pickedImage = null),
                            child: const Padding(
                              padding: EdgeInsets.all(8),
                              child: Icon(
                                Icons.close_rounded,
                                color: Colors.white,
                                size: 18,
                              ),
                            ),
                          ),
                        ),
                      ),
                    ],
                  )
                : Container(
                    color: AppColors.surfaceAlt,
                    alignment: Alignment.center,
                    child: Column(
                      mainAxisAlignment: MainAxisAlignment.center,
                      children: [
                        Icon(
                          Icons.image_outlined,
                          size: 48,
                          color: AppColors.textTertiary,
                        ),
                        const SizedBox(height: 8),
                        Text(
                          'Adicione uma foto',
                          style: AppText.caption,
                        ),
                      ],
                    ),
                  ),
          ),
          Row(
            children: [
              Expanded(
                child: _imageBtn(
                  icon: Icons.photo_camera_rounded,
                  label: 'Câmara',
                  onTap: _takePhoto,
                ),
              ),
              Container(width: 1, height: 44, color: AppColors.border),
              Expanded(
                child: _imageBtn(
                  icon: Icons.photo_library_rounded,
                  label: 'Galeria',
                  onTap: _pickImage,
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  Widget _imageBtn({
    required IconData icon,
    required String label,
    required VoidCallback onTap,
  }) {
    return Material(
      color: Colors.transparent,
      child: InkWell(
        onTap: onTap,
        child: Padding(
          padding: const EdgeInsets.symmetric(vertical: 12),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Icon(icon, size: 18, color: AppColors.primary),
              const SizedBox(width: 8),
              Text(
                label,
                style: const TextStyle(
                  color: AppColors.primary,
                  fontWeight: FontWeight.w600,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _textField({
    required TextEditingController controller,
    required String hint,
    required IconData icon,
    int maxLines = 1,
  }) {
    return Container(
      decoration: AppDecorations.outlined(),
      child: TextField(
        controller: controller,
        maxLines: maxLines,
        style: AppText.body,
        decoration: InputDecoration(
          prefixIcon: maxLines == 1
              ? Icon(icon, color: AppColors.textSecondary)
              : Padding(
                  padding: const EdgeInsets.only(left: 12, top: 14),
                  child: Icon(icon, color: AppColors.textSecondary),
                ),
          prefixIconConstraints: maxLines == 1
              ? null
              : const BoxConstraints(minWidth: 40, minHeight: 40),
          hintText: hint,
          hintStyle: TextStyle(color: AppColors.textTertiary),
          border: InputBorder.none,
          contentPadding: const EdgeInsets.symmetric(
            horizontal: 12,
            vertical: 14,
          ),
        ),
      ),
    );
  }

  Widget _buildCategoryGrid() {
    return GridView.builder(
      shrinkWrap: true,
      physics: const NeverScrollableScrollPhysics(),
      itemCount: itemCategories.length,
      gridDelegate: const SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 3,
        crossAxisSpacing: 10,
        mainAxisSpacing: 10,
        childAspectRatio: 1,
      ),
      itemBuilder: (_, i) {
        final c = itemCategories[i];
        final selected = _selectedCategory?.id == c.id;
        return AnimatedContainer(
          duration: const Duration(milliseconds: 180),
          decoration: BoxDecoration(
            color: selected ? c.color : AppColors.surface,
            borderRadius: BorderRadius.circular(AppRadius.lg),
            border: Border.all(
              color: selected ? c.color : AppColors.border,
              width: 1.5,
            ),
            boxShadow: selected
                ? [
                    BoxShadow(
                      color: c.color.withValues(alpha: 0.3),
                      blurRadius: 12,
                      offset: const Offset(0, 6),
                    )
                  ]
                : null,
          ),
          child: Material(
            color: Colors.transparent,
            child: InkWell(
              borderRadius: BorderRadius.circular(AppRadius.lg),
              onTap: () {
                setState(() {
                  if (_selectedCategory?.id != c.id) {
                    _selectedCategory = c;
                    _selectedSubcategory = null;
                  }
                });
              },
              child: Padding(
                padding: const EdgeInsets.all(8),
                child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    Icon(
                      c.icon,
                      size: 28,
                      color: selected ? Colors.white : c.color,
                    ),
                    const SizedBox(height: 6),
                    Text(
                      c.name,
                      textAlign: TextAlign.center,
                      style: TextStyle(
                        fontSize: 12,
                        fontWeight: FontWeight.w600,
                        color: selected
                            ? Colors.white
                            : AppColors.textPrimary,
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        );
      },
    );
  }
}