using Gee;

using Dino.Entities;

namespace Dino {

public class MessageStorage : StreamInteractionModule, Object {
    public static ModuleIdentity<MessageStorage> IDENTITY = new ModuleIdentity<MessageStorage>("message_cache");
    public string id { get { return IDENTITY.id; } }

    private StreamInteractor stream_interactor;
    private Database db;

    private HashMap<Conversation, Gee.TreeSet<Message>> messages = new HashMap<Conversation, Gee.TreeSet<Message>>(Conversation.hash_func, Conversation.equals_func);

    public static void start(StreamInteractor stream_interactor, Database db) {
        MessageStorage m = new MessageStorage(stream_interactor, db);
        stream_interactor.add_module(m);
    }

    private MessageStorage(StreamInteractor stream_interactor, Database db) {
        this.stream_interactor = stream_interactor;
        this.db = db;
    }

    public void add_message(Message message, Conversation conversation) {
        message.persist(db);
        init_conversation(conversation);
        messages[conversation].add(message);
    }

    public Gee.List<Message> get_messages(Conversation conversation, int count = 50) {
        init_conversation(conversation);
        Gee.List<Message> ret = new ArrayList<Message>(Message.equals_func);
        BidirIterator<Message> iter = messages[conversation].bidir_iterator();
        iter.last();
        while (iter.valid && ret.size < count) {
            iter.previous();
            ret.insert(0, iter.get());
        }
        return ret;
    }

    public Message? get_last_message(Conversation conversation) {
        init_conversation(conversation);
        if (messages[conversation].size > 0) {
            return messages[conversation].last();
        }
        return null;
    }

    public Gee.List<Message>? get_messages_before(Conversation? conversation, DateTime before, int count = 20) {
        Gee.List<Message> db_messages = db.get_messages(conversation.counterpart, conversation.account, Util.get_message_type_for_conversation(conversation), count, before);
        return db_messages;
    }

    public Message? get_message_by_id(string stanza_id, Conversation conversation) {
        init_conversation(conversation);
        foreach (Message message in messages[conversation]) {
            if (message.stanza_id == stanza_id) return message;
        }
        return null;
    }

    private void init_conversation(Conversation conversation) {
        if (!messages.has_key(conversation)) {
            messages[conversation] = new Gee.TreeSet<Message>((a, b) => { return a.local_time.compare(b.local_time); });
            Gee.List<Message> db_messages = db.get_messages(conversation.counterpart, conversation.account, Util.get_message_type_for_conversation(conversation), 50, null);
            messages[conversation].add_all(db_messages);
        }
    }
}

}