/*
 * Copyright (c) 2018, Daniel Gultsch All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors
 * may be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package eu.siacs.conversations.ui;

import android.app.Activity;
import android.app.Fragment;
import android.databinding.DataBindingUtil;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

import de.timroes.android.listview.EnhancedListView;
import eu.siacs.conversations.Config;
import eu.siacs.conversations.R;
import eu.siacs.conversations.databinding.FragmentConversationsOverviewBinding;
import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.ui.adapter.ConversationAdapter;
import eu.siacs.conversations.ui.interfaces.OnConversationArchived;
import eu.siacs.conversations.ui.interfaces.OnConversationSelected;
import eu.siacs.conversations.ui.util.PendingItem;
import eu.siacs.conversations.ui.util.ScrollState;

public class ConversationsOverviewFragment extends XmppFragment implements EnhancedListView.OnDismissCallback {

	private static final String STATE_SCROLL_POSITION = ConversationsOverviewFragment.class.getName()+".scroll_state";

	private final List<Conversation> conversations = new ArrayList<>();
	private final PendingItem<Conversation> swipedConversation = new PendingItem<>();
	private final PendingItem<ScrollState> pendingScrollState = new PendingItem<>();
	private FragmentConversationsOverviewBinding binding;
	private ConversationAdapter conversationsAdapter;
	private XmppActivity activity;

	public static Conversation getSuggestion(Activity activity) {
		final Conversation exception;
		Fragment fragment = activity.getFragmentManager().findFragmentById(R.id.main_fragment);
		if (fragment != null && fragment instanceof ConversationsOverviewFragment) {
			exception = ((ConversationsOverviewFragment) fragment).swipedConversation.peek();
		} else {
			exception = null;
		}
		return getSuggestion(activity, exception);
	}

	public static Conversation getSuggestion(Activity activity, Conversation exception) {
		Fragment fragment = activity.getFragmentManager().findFragmentById(R.id.main_fragment);
		if (fragment != null && fragment instanceof ConversationsOverviewFragment) {
			List<Conversation> conversations = ((ConversationsOverviewFragment) fragment).conversations;
			if (conversations.size() > 0) {
				Conversation suggestion = conversations.get(0);
				if (suggestion == exception) {
					if (conversations.size() > 1) {
						return conversations.get(1);
					}
				} else {
					return suggestion;
				}
			}
		}
		return null;

	}

	@Override
	public void onActivityCreated(Bundle savedInstanceState) {
		super.onActivityCreated(savedInstanceState);
		if (savedInstanceState == null) {
			return;
		}
		pendingScrollState.push(savedInstanceState.getParcelable(STATE_SCROLL_POSITION));
	}

	@Override
	public void onAttach(Activity activity) {
		super.onAttach(activity);
		if (activity instanceof XmppActivity) {
			this.activity = (XmppActivity) activity;
		} else {
			throw new IllegalStateException("Trying to attach fragment to activity that is not an XmppActivity");
		}
	}

	@Override
	public void onDetach() {
		super.onDetach();
		this.activity = null;
	}

	@Override
	public View onCreateView(final LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
		Log.d(Config.LOGTAG, "onCreateView");
		this.binding = DataBindingUtil.inflate(inflater, R.layout.fragment_conversations_overview, container, false);
		this.binding.fab.setOnClickListener((view) -> StartConversationActivity.launch(getActivity()));

		this.conversationsAdapter = new ConversationAdapter(this.activity, this.conversations);
		this.binding.list.setAdapter(this.conversationsAdapter);
		this.binding.list.setOnItemClickListener((parent, view, position, id) -> {
			Conversation conversation = this.conversations.get(position);
			if (activity instanceof OnConversationSelected) {
				((OnConversationSelected) activity).onConversationSelected(conversation);
			} else {
				Log.w(ConversationsOverviewFragment.class.getCanonicalName(), "Activity does not implement OnConversationSelected");
			}
		});
		this.binding.list.setDismissCallback(this);
		this.binding.list.enableSwipeToDismiss();
		this.binding.list.setSwipeDirection(EnhancedListView.SwipeDirection.BOTH);
		this.binding.list.setSwipingLayout(R.id.swipeable_item);
		this.binding.list.setUndoStyle(EnhancedListView.UndoStyle.SINGLE_POPUP);
		this.binding.list.setUndoHideDelay(5000);
		this.binding.list.setRequireTouchBeforeDismiss(false);
		return binding.getRoot();
	}

	@Override
	public void onBackendConnected() {
		refresh();
	}

	@Override
	public void onSaveInstanceState(Bundle bundle) {
		super.onSaveInstanceState(bundle);
		ScrollState scrollState = getScrollState();
		if (scrollState != null) {
			bundle.putParcelable(STATE_SCROLL_POSITION, scrollState);
		}
	}

	private ScrollState getScrollState() {
		if (this.binding == null) {
			return null;
		}
		int position = this.binding.list.getFirstVisiblePosition();
		final View view = this.binding.list.getChildAt(0);
		if (view != null) {
			return new ScrollState(position,view.getTop());
		} else {
			return new ScrollState(position, 0);
		}
	}

	@Override
	public void onStart() {
		super.onStart();
		Log.d(Config.LOGTAG, "ConversationsOverviewFragment.onStart()");
		if (activity.xmppConnectionService != null) {
			refresh();
		}
	}

	@Override
	public void onResume() {
		super.onResume();
		Log.d(Config.LOGTAG, "ConversationsOverviewFragment.onResume()");
	}

	@Override
	void refresh() {
		if (this.binding == null || this.activity == null) {
			Log.d(Config.LOGTAG,"ConversationsOverviewFragment.refresh() skipped updated because view binding or activity was null");
			return;
		}
		this.activity.xmppConnectionService.populateWithOrderedConversations(this.conversations);
		Conversation removed = this.swipedConversation.peek();
		if (removed != null) {
			if (removed.isRead()) {
				this.conversations.remove(removed);
			} else {
				this.binding.list.discardUndo(); //will be ignored during discard when conversation is unRead
			}
		}
		this.conversationsAdapter.notifyDataSetChanged();
		ScrollState scrollState = pendingScrollState.pop();
		if (scrollState != null) {
			setScrollPosition(scrollState);
		}
	}

	private void setScrollPosition(ScrollState scrollPosition) {
		if (scrollPosition != null) {
			this.binding.list.setSelectionFromTop(scrollPosition.position, scrollPosition.offset);
		}
	}

	@Override
	public EnhancedListView.Undoable onDismiss(EnhancedListView listView, int position) {
		try {
			swipedConversation.push(this.conversationsAdapter.getItem(position));
		} catch (IndexOutOfBoundsException e) {
			return null;
		}
		this.conversationsAdapter.remove(swipedConversation.peek());
		this.activity.xmppConnectionService.markRead(swipedConversation.peek());

		if (position == 0 && this.conversationsAdapter.getCount() == 0) {
			final Conversation c = swipedConversation.pop();
			activity.xmppConnectionService.archiveConversation(c);
			return null;
		}
		final boolean formerlySelected = ConversationFragment.getConversation(getActivity()) == swipedConversation.peek();
		if (activity instanceof OnConversationArchived) {
			((OnConversationArchived) activity).onConversationArchived(swipedConversation.peek());
		}
		return new EnhancedListView.Undoable() {

			@Override
			public void undo() {
				Conversation c = swipedConversation.pop();
				conversationsAdapter.insert(c, position);
				if (formerlySelected) {
					if (activity instanceof OnConversationSelected) {
						((OnConversationSelected) activity).onConversationSelected(c);
					}
				}
				if (position > listView.getLastVisiblePosition()) {
					listView.smoothScrollToPosition(position);
				}
			}

			@Override
			public void discard() {
				Conversation c = swipedConversation.pop();
				if (!c.isRead() && c.getMode() == Conversation.MODE_SINGLE) {
					return;
				}
				activity.xmppConnectionService.archiveConversation(c);
			}

			@Override
			public String getTitle() {
				if (swipedConversation.peek().getMode() == Conversation.MODE_MULTI) {
					return getResources().getString(R.string.title_undo_swipe_out_muc);
				} else {
					return getResources().getString(R.string.title_undo_swipe_out_conversation);
				}
			}
		};
	}
}