import 'package:flutter/material.dart';
import '../data/instruction_repository.dart';
import '../models/instruction.dart';

class InstructionProvider extends ChangeNotifier {
  final InstructionRepository _repository;

  InstructionProvider(this._repository);

  bool _isLoading = false;
  List<Instruction> _instructions = [];
  Set<String> _selectedTags = {};

  bool get isLoading => _isLoading;
  List<Instruction> get instructions => _instructions;

  List<Instruction> get filteredInstructions {
    if (_selectedTags.isEmpty) {
      return _instructions;
    }
    return _instructions
        .where((instr) => _selectedTags.every((tag) => instr.tags.contains(tag)))
        .toList();
  }

  Set<String> get allAvailableTags {
    return _instructions.fold<Set<String>>(
        <String>{}, (prev, element) => prev..addAll(element.tags));
  }

  Set<String> get selectedTags => _selectedTags;


  Future<void> loadInstructions() async {
    _isLoading = true;
    notifyListeners();
    _instructions = await _repository.getInstructions();
    _isLoading = false;
    notifyListeners();
  }

  Future<void> addInstruction(String title, String content, List<String> tags) async {
    final newInstruction = Instruction(
      title: title,
      content: content,
      tags: tags,
      createdAt: DateTime.now(),
    );
    await _repository.addInstruction(newInstruction);
    await loadInstructions(); 
  }

  Future<void> updateInstruction(Instruction instruction) async {
    await _repository.updateInstruction(instruction);
    await loadInstructions();
  }

  Future<void> deleteInstruction(String id) async {
    await _repository.deleteInstruction(id);
    _instructions.removeWhere((instr) => instr.id == id);
    notifyListeners();
  }

  void toggleTagFilter(String tag) {
    if (_selectedTags.contains(tag)) {
      _selectedTags.remove(tag);
    } else {
      _selectedTags.add(tag);
    }
    notifyListeners();
  }
}