package io.dropwizard.logging;

import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.core.Appender;
import ch.qos.logback.core.OutputStreamAppender;
import ch.qos.logback.core.encoder.LayoutWrappingEncoder;
import ch.qos.logback.core.spi.DeferredProcessingAware;
import io.dropwizard.logging.async.AsyncAppenderFactory;
import io.dropwizard.logging.filter.LevelFilterFactory;
import io.dropwizard.logging.layout.LayoutFactory;

A base implementation of AppenderFactory producing an appender based on OutputStreamAppender. /**
 * A base implementation of {@link AppenderFactory} producing an appender based on {@link OutputStreamAppender}.
 */
public abstract class AbstractOutputStreamAppenderFactory<E extends DeferredProcessingAware>
    extends AbstractAppenderFactory<E> {

    protected abstract OutputStreamAppender<E> appender(LoggerContext context);

    @Override
    public Appender<E> build(LoggerContext context, String applicationName, LayoutFactory<E> layoutFactory,
                             LevelFilterFactory<E> levelFilterFactory, AsyncAppenderFactory<E> asyncAppenderFactory) {
        final OutputStreamAppender<E> appender = appender(context);
        final LayoutWrappingEncoder<E> layoutEncoder = new LayoutWrappingEncoder<>();
        layoutEncoder.setLayout(buildLayout(context, layoutFactory));
        appender.setEncoder(layoutEncoder);

        appender.addFilter(levelFilterFactory.build(threshold));
        getFilterFactories().forEach(f -> appender.addFilter(f.build()));
        appender.start();
        return wrapAsync(appender, asyncAppenderFactory);
    }
}