package de.thedevstack.conversationsplus.ui.listeners;

import android.view.View;
import android.widget.ListView;
import android.widget.Toast;

import com.orangegangsters.github.swipyrefreshlayout.library.SwipyRefreshLayout;

import java.util.List;

import de.thedevstack.conversationsplus.entities.Conversation;
import de.thedevstack.conversationsplus.entities.Message;
import de.thedevstack.conversationsplus.services.XmppConnectionService;
import de.thedevstack.conversationsplus.ui.ConversationActivity;
import de.thedevstack.conversationsplus.ui.ConversationFragment;
import de.thedevstack.conversationsplus.ui.adapter.MessageAdapter;

/**
 * This listener updates the UI when messages are loaded from the server.
 */
public class ConversationMoreMessagesLoadedListener implements XmppConnectionService.OnMoreMessagesLoaded {
    private SwipyRefreshLayout swipeLayout;
    private List<Message> messageList;
    private ConversationFragment fragment;
    private ListView messagesView;
    private MessageAdapter messageListAdapter;
    private Toast messageLoaderToast;
    /*
    The current loading status
     */
    private boolean loadingMessages = false;
    /**
     * Whether the user is loading only history messages or not.
     * History messages are messages which are older than the oldest in the database.
     */
    private boolean loadHistory = true;

    public ConversationMoreMessagesLoadedListener(SwipyRefreshLayout swipeLayout, List<Message> messageList, ConversationFragment fragment, ListView messagesView, MessageAdapter messageListAdapter) {
        this.swipeLayout = swipeLayout;
        this.messageList = messageList;
        this.fragment = fragment;
        this.messagesView = messagesView;
        this.messageListAdapter = messageListAdapter;
    }

    public void setLoadHistory(boolean value) {
        this.loadHistory = value;
    }

    public void setLoadingInProgress() {
        this.loadingMessages = true;
    }

    public boolean isLoadingInProgress() {
        return this.loadingMessages;
    }

    @Override
    public void onMoreMessagesLoaded(final int c, final Conversation conversation) {
        ConversationActivity activity = (ConversationActivity) fragment.getActivity();
        // Current selected conversation is not the same the messages are loaded - skip updating message view and hide loading graphic
        if (activity.getSelectedConversation() != conversation) {
            activity.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    swipeLayout.setRefreshing(false);
                }
            });
            return;
        }
        // No new messages are loaded
        if (0 == c) {
            if (this.loadHistory) {
                conversation.setHasMessagesLeftOnServer(false);
            }
            activity.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    swipeLayout.setRefreshing(false);
                }
            });
        }
        activity.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                final int oldPosition = messagesView.getFirstVisiblePosition(); // Always 0 - because loading starts always when hitting the top
                String uuid = null;
                boolean oldMessageListWasEmpty = messageList.isEmpty();
                if (-1 < oldPosition && messageList.size() > oldPosition) {
                    Message message = messageList.get(oldPosition);
                    uuid = message != null ? message.getUuid() : null;
                }
                View v = messagesView.getChildAt(0);
                final int pxOffset = (v == null) ? 0 : v.getTop();

                conversation.populateWithMessages(messageList); // This overrides the old message list
                fragment.updateStatusMessages(); // This adds "messages" to the list for the status
                messageListAdapter.notifyDataSetChanged();
                loadingMessages = false; // Loading of messages is finished - next query can be loaded

                int pos = getIndexOf(uuid, messageList);

                if (!oldMessageListWasEmpty) {
                    messagesView.setSelectionFromTop(pos, pxOffset);
                }

                if (messageLoaderToast != null) {
                    messageLoaderToast.cancel();
                }
                swipeLayout.setRefreshing(false);
            }
        });
    }

    @Override
    public void informUser(final int resId) {
        final ConversationActivity activity = (ConversationActivity) fragment.getActivity();

        activity.runOnUiThread(new Runnable() {
            @Override
            public void run() {
                if (messageLoaderToast != null) {
                    messageLoaderToast.cancel();
                }
                messageLoaderToast = Toast.makeText(activity, resId, Toast.LENGTH_LONG);
                messageLoaderToast.show();
            }
        });

    }

    private int getIndexOf(String uuid, List<Message> messages) {
        if (uuid == null) {
            return 0;
        }
        for (int i = 0; i < messages.size(); ++i) {
            if (uuid.equals(messages.get(i).getUuid())) {
                return i;
            }
        }
        return 0;
    }
}