/**
 * This file is part of Graylog.
 *
 * Graylog is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Graylog is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Graylog.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.graylog2.inputs.codecs;

import com.fasterxml.jackson.core.JsonParseException;
import org.graylog2.inputs.TestHelper;
import org.graylog2.plugin.Message;
import org.graylog2.plugin.configuration.Configuration;
import org.graylog2.plugin.journal.RawMessage;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnit;
import org.mockito.junit.MockitoRule;

import java.nio.charset.StandardCharsets;
import java.util.Collections;

import static org.assertj.core.api.Assertions.assertThat;
import static org.hamcrest.Matchers.isA;
import static org.junit.Assume.assumeTrue;

public class GelfCodecTest {
    @Rule
    public final MockitoRule mockitoRule = MockitoJUnit.rule();

    @Rule
    public final ExpectedException expectedException = ExpectedException.none();

    @Mock
    private GelfChunkAggregator aggregator;

    private GelfCodec codec;

    @Before
    public void setUp() {
        codec = new GelfCodec(new Configuration(Collections.emptyMap()), aggregator);
    }

    @Test(expected = IllegalStateException.class)
    public void decodeDoesNotThrowIllegalArgumentExceptionIfJsonIsInvalid() throws Exception {
        // this fails gelf parsing, but empty Payloads are now ok.
        final RawMessage rawMessage = new RawMessage(new byte[0]);
        codec.decode(rawMessage);
    }

    @Test
    public void decodeFiltersOutVersionField() throws Exception {
        final String json = "{"
                + "\"version\": \"1.1\","
                + "\"host\": \"example.org\","
                + "\"short_message\": \"A short message that helps you identify what is going on\""
                + "}";

        final RawMessage rawMessage = new RawMessage(json.getBytes(StandardCharsets.UTF_8));
        final Message message = codec.decode(rawMessage);

        assertThat(message).isNotNull();
        assertThat(message.getField("version")).isNull();
        assertThat(message.getField("source")).isEqualTo("example.org");
    }

    @Test
    public void decodeAllowsSettingCustomVersionField() throws Exception {
        final String json = "{"
                + "\"version\": \"1.1\","
                + "\"host\": \"example.org\","
                + "\"short_message\": \"A short message that helps you identify what is going on\","
                + "\"_version\": \"3.11\""
                + "}";

        final RawMessage rawMessage = new RawMessage(json.getBytes(StandardCharsets.UTF_8));
        final Message message = codec.decode(rawMessage);

        assertThat(message).isNotNull();
        assertThat(message.getField("version")).isEqualTo("3.11");
        assertThat(message.getField("source")).isEqualTo("example.org");
    }

    @Test
    public void decodeBuildsValidMessageObject() throws Exception {
        final String json = "{"
                + "\"version\": \"1.1\","
                + "\"host\": \"example.org\","
                + "\"short_message\": \"A short message that helps you identify what is going on\","
                + "\"full_message\": \"Backtrace here\\n\\nMore stuff\","
                + "\"timestamp\": 1385053862.3072,"
                + "\"level\": 1,"
                + "\"_user_id\": 9001,"
                + "\"_some_info\": \"foo\","
                + "\"_some_env_var\": \"bar\""
                + "}";

        final RawMessage rawMessage = new RawMessage(json.getBytes(StandardCharsets.UTF_8));
        final Message message = codec.decode(rawMessage);

        assertThat(message).isNotNull();
        assertThat(message.getField("source")).isEqualTo("example.org");
        assertThat(message.getField("message")).isEqualTo("A short message that helps you identify what is going on");
        assertThat(message.getField("user_id")).isEqualTo(9001L);
        assertThat(message.getFieldNames()).containsOnly(
                "_id", "source", "message", "full_message", "timestamp", "level",
                "user_id", "some_info", "some_env_var");
    }
    @Test
    public void decodeLargeCompressedMessageFails() throws Exception {
        expectedException.expect(IllegalStateException.class);
        expectedException.expectMessage("JSON is null/could not be parsed (invalid JSON)");
        expectedException.expectCause(isA(JsonParseException.class));

        final Configuration configuration = new Configuration(Collections.singletonMap("decompress_size_limit", 100));
        final GelfCodec codec = new GelfCodec(configuration, aggregator);
        final String json = "{"
            + "\"version\": \"1.1\","
            + "\"host\": \"example.org\","
            + "\"short_message\": \"A short message that helps you identify what is going on\","
            + "\"full_message\": \"Backtrace here\\n\\nMore stuff\","
            + "\"timestamp\": 1385053862.3072,"
            + "\"level\": 1,"
            + "\"_some_bytes1\": \"Lorem ipsum dolor sit amet, consetetur sadipscing elitr, \","
            + "\"_some_bytes2\": \"sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, \","
            + "\"_some_bytes2\": \"sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum.\""
            + "}";

        final byte[] payload = TestHelper.zlibCompress(json);
        assumeTrue(payload.length > 100);
        final RawMessage rawMessage = new RawMessage(payload);
        codec.decode(rawMessage);
    }

    @Test
    public void getAggregatorReturnsGelfChunkAggregator() throws Exception {
        assertThat(codec.getAggregator()).isSameAs(aggregator);
    }
}