using GLib;
using Gee;

public class MessageListModel : Object, ListModel 
{
    public signal void messages_changed();

    public SortedSet<Message> messages {
        owned get { return _messages.read_only_view; }
    }

    public bool is_group_chat {
        get {
            return participants.size > 2;
        }
    }

    public string conversation_guid { get; private set; }

    private SortedSet<Message> _messages;
    private HashSet<string> participants = new HashSet<string>();
    
    public MessageListModel(string conversation_guid) {
        _messages = new TreeSet<Message>((a, b) => {
            // Sort by date in descending order (newest first)
            return a.date.compare(b.date);
        });

        Repository.get_instance().messages_updated.connect(got_messages_updated);
        this.conversation_guid = conversation_guid;
    }
    
    public void load_messages() {
        try {
            Message[] messages = Repository.get_instance().get_messages(conversation_guid);
            
            // Clear existing set
            uint old_count = _messages.size;
            _messages.clear();
            participants.clear();
            
            // Notify of removal
            if (old_count > 0) {
                items_changed(0, old_count, 0);
            }
            
            // Process each conversation
            uint position = 0;
            
            for (int i = 0; i < messages.length; i++) {
                var message = messages[i];
                _messages.add(message);
                participants.add(message.sender);

                position++;
            }
            
            // Notify of additions
            if (position > 0) {
                items_changed(0, 0, position);
            }
        } catch (Error e) {
            warning("Failed to load messages: %s", e.message);
        }

        messages_changed();
    }

    private void got_messages_updated(string conversation_guid) {
        if (conversation_guid == this.conversation_guid) {
            load_messages();
        }
    }
    
    // ListModel implementation
    public Type get_item_type() {
        return typeof(Message);
    }
    
    public uint get_n_items() {
        return _messages.size;
    }
    
    public Object? get_item(uint position) {
        return _messages.to_array()[position];
    }
}