function attachEvents() {
    let adress = 'https://rest-messanger.firebaseio.com/messanger.json';
    let refreshBtn = document.querySelector('#refresh');
    refreshBtn.addEventListener('click', () => {
        fetch(adress)
            .then(response => response.json())
            .then(data => {
                let reducedMsg = Object.values(data).reduce((a, x) => {
                    a += `${x.author}: ${x.content}\n`;
                }, '')
                let msgElem = document.querySelector('#messages')
                msgElem.textContent = reducedMsg;

            })
    })

    let enterBtn = document.querySelector('#submit');
    enterBtn.addEventListener('click', () => {
        let author = document.querySelector('#author');
        let content = document.querySelector('#content');
        fetch(adress, {
            method: 'POST',
            body: JSON.stringify({
                author: author.value,
                content: content.value,
            })
        });
        author.value = '';
        content.value = '';

    });
}

attachEvents();