/*
 * 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.services;

import android.database.Cursor;
import android.os.SystemClock;
import android.util.Log;

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

import eu.siacs.conversations.Config;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.entities.Conversational;
import eu.siacs.conversations.entities.IndividualMessage;
import eu.siacs.conversations.entities.Message;
import eu.siacs.conversations.entities.StubConversation;
import eu.siacs.conversations.ui.interfaces.OnSearchResultsAvailable;
import eu.siacs.conversations.utils.Cancellable;
import eu.siacs.conversations.utils.MessageUtils;
import eu.siacs.conversations.utils.ReplacingSerialSingleThreadExecutor;
import eu.siacs.conversations.xmpp.Jid;

public class MessageSearchTask implements Runnable, Cancellable {

	private static final ReplacingSerialSingleThreadExecutor EXECUTOR = new ReplacingSerialSingleThreadExecutor(MessageSearchTask.class.getName());

	private final XmppConnectionService xmppConnectionService;
	private final List<String> term;
	private final String uuid;
	private final OnSearchResultsAvailable onSearchResultsAvailable;

	private boolean isCancelled = false;

	private MessageSearchTask(XmppConnectionService xmppConnectionService, List<String> term, final String uuid, OnSearchResultsAvailable onSearchResultsAvailable) {
		this.xmppConnectionService = xmppConnectionService;
		this.term = term;
		this.uuid = uuid;
		this.onSearchResultsAvailable = onSearchResultsAvailable;
	}

	public static void search(XmppConnectionService xmppConnectionService, List<String> term, final String uuid, OnSearchResultsAvailable onSearchResultsAvailable) {
		new MessageSearchTask(xmppConnectionService, term, uuid, onSearchResultsAvailable).executeInBackground();
	}

	public static void cancelRunningTasks() {
		EXECUTOR.cancelRunningTasks();
	}

	@Override
	public void cancel() {
		this.isCancelled = true;
	}

	@Override
	public void run() {
		long startTimestamp = SystemClock.elapsedRealtime();
		Cursor cursor = null;
		try {
			final HashMap<String, Conversational> conversationCache = new HashMap<>();
			final List<Message> result = new ArrayList<>();
			cursor = xmppConnectionService.databaseBackend.getMessageSearchCursor(term, uuid);
			long dbTimer = SystemClock.elapsedRealtime();
			if (isCancelled) {
				Log.d(Config.LOGTAG, "canceled search task");
				return;
			}
			if (cursor != null && cursor.getCount() > 0) {
				cursor.moveToLast();
				final int indexBody = cursor.getColumnIndex(Message.BODY);
				final int indexOob = cursor.getColumnIndex(Message.OOB);
				final int indexConversation = cursor.getColumnIndex(Message.CONVERSATION);
				final int indexAccount = cursor.getColumnIndex(Conversation.ACCOUNT);
				final int indexContact = cursor.getColumnIndex(Conversation.CONTACTJID);
				final int indexMode = cursor.getColumnIndex(Conversation.MODE);
				do {
					if (isCancelled) {
						Log.d(Config.LOGTAG, "canceled search task");
						return;
					}
					final String body = cursor.getString(indexBody);
					final boolean oob = cursor.getInt(indexOob) > 0;
					if (MessageUtils.treatAsDownloadable(body,oob,false)) {
						continue;
					}
					final String conversationUuid = cursor.getString(indexConversation);
					Conversational conversation = conversationCache.get(conversationUuid);
					if (conversation == null) {
						String accountUuid = cursor.getString(indexAccount);
						String contactJid = cursor.getString(indexContact);
						int mode = cursor.getInt(indexMode);
						conversation = findOrGenerateStub(conversationUuid, accountUuid, contactJid, mode);
						conversationCache.put(conversationUuid, conversation);
					}
					Message message = IndividualMessage.fromCursor(cursor, conversation);
					result.add(message);
				} while (cursor.moveToPrevious());
			}
			long stopTimestamp = SystemClock.elapsedRealtime();
			Log.d(Config.LOGTAG, "found " + result.size() + " messages in " + (stopTimestamp - startTimestamp) + "ms"+ " (db was "+(dbTimer - startTimestamp)+"ms)");
			onSearchResultsAvailable.onSearchResultsAvailable(term, result);
		} catch (Exception e) {
			Log.d(Config.LOGTAG, "exception while searching ", e);
		} finally {
			if (cursor != null) {
				cursor.close();
			}
		}
	}

	private Conversational findOrGenerateStub(String conversationUuid, String accountUuid, String contactJid, int mode) throws Exception {
		Conversation conversation = xmppConnectionService.findConversationByUuid(conversationUuid);
		if (conversation != null) {
			return conversation;
		}
		Account account = xmppConnectionService.findAccountByUuid(accountUuid);
		Jid jid = Jid.of(contactJid);
		if (account != null && jid != null) {
			return new StubConversation(account, conversationUuid, jid.asBareJid(), mode);
		}
		throw new Exception("Unable to generate stub for " + contactJid);
	}

	private void executeInBackground() {
		EXECUTOR.execute(this);
	}
}
