labs-mobile-applications/app/src/main/java/com/example/myapplication/MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import androidx.activity.ComponentActivity
import androidx.lifecycle.lifecycleScope
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import kotlinx.coroutines.launch

class MainActivity : ComponentActivity() {

    private lateinit var etInput: EditText
    private lateinit var btnAdd: Button
    private lateinit var recyclerView: RecyclerView
    private lateinit var adapter: NoteAdapter

    private lateinit var db: AppDatabase

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        etInput = findViewById(R.id.etInput)
        btnAdd = findViewById(R.id.btnAdd)
        recyclerView = findViewById(R.id.recyclerView)

        adapter = NoteAdapter(emptyList())
        recyclerView.layoutManager = LinearLayoutManager(this)
        recyclerView.adapter = adapter

        db = AppDatabase.getDatabase(this)

        // Добавляем заметку
        btnAdd.setOnClickListener {
            val text = etInput.text.toString()
            if (text.isNotEmpty()) {
                lifecycleScope.launch {
                    db.noteDao().insert(NoteEntity(text = text))
                }
                etInput.text.clear()
            }
        }

        // Подписываемся на изменения
        lifecycleScope.launch {
            db.noteDao().getAll().collect { notes ->
                adapter.update(notes)
            }
        }
    }
}