const MszMessagesThread = function(thread) {
    if(!(thread instanceof Element))
        throw 'thread must be an element';

    const messages = Array.from(thread.querySelectorAll('.js-messages-message')).map(elem => new MszMessagesThreadMessage(elem));
    const message = messages.find(msg => msg.isFull());

    return {
        getMessage: () => message,
        getMessages: () => messages,
    };
};

const MszMessagesThreadMessage = function(message) {
    if(!(message instanceof Element))
        throw 'message must be an element';

    const msgId = message.dataset.msgId;
    const type = message.dataset.msgType;
    const url = message.dataset.msgUrl;

    if(type === 'snip') {
        message.addEventListener('click', ev => {
            if(typeof url !== 'string')
                return;

            let target = ev.target;
            while(target !== message) {
                if(target instanceof HTMLAnchorElement)
                    return;

                target = target.parentNode;
            }

            ev.preventDefault();
            location.assign(url);
        });
    } else if(type === 'full') {
        message.scrollIntoView({
            behavior: 'smooth',
            block: 'start',
        });
    }

    const isRead = () => message.dataset.msgRead === 'read';
    const setRead = state => {
        message.dataset.msgRead = state ? 'read' : 'unread';
    };

    const isSent = () => message.dataset.msgSent === 'sent';
    const setSent = state => {
        message.dataset.msgRead = state ? 'sent' : 'draft';
    };

    const isDeleted = () => message.dataset.msgDeleted === 'yes';
    const setDeleted = state => {
        if(state) {
            message.dataset.msgDeleted = 'yes';
            message.classList.add('messages-message-deleted');
        } else {
            message.dataset.msgDeleted = 'no';
            message.classList.remove('messages-message-deleted');
        }
    };

    return {
        getId: () => msgId,
        getType: () => type,
        isFull: () => type === 'full',
        isSnippet: () => type === 'snip',
        isRead: isRead,
        setRead: setRead,
        isSent: isSent,
        setSent: setSent,
        isDeleted: isDeleted,
        setDeleted: setDeleted,
    };
};