package eu.dnetlib.manager.wf.nodes;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanNameAware;

import eu.dnetlib.manager.wf.annotations.WfInputParam;
import eu.dnetlib.manager.wf.annotations.WfOutputParam;
import eu.dnetlib.manager.wf.workflows.procs.Env;
import eu.dnetlib.manager.wf.workflows.procs.ProcessEngine;
import eu.dnetlib.manager.wf.workflows.procs.Token;
import eu.dnetlib.manager.wf.workflows.util.NodeCallback;

public abstract class ProcessNode implements BeanNameAware {

	private static final Log log = LogFactory.getLog(ProcessEngine.class);

	private String beanName;

	private String nodeName;

	public abstract void execute(final Token token, NodeCallback callback);

	public final void initInputParams(final Env env) {
		findFields(getClass(), WfInputParam.class).forEach(field -> {
			final String annName = field.getAnnotation(WfInputParam.class).value();
			if (StringUtils.isNotBlank(annName)) {
				fieldValue(field, env.getAttribute(annName, field.getType()));
			} else {
				fieldValue(field, env.getAttribute(field.getName(), field.getType()));
			}

		});
	}

	public final void saveOutputParams(final Env env) {
		findFields(getClass(), WfOutputParam.class).forEach(field -> {
			final String annName = field.getAnnotation(WfOutputParam.class).value();
			if (StringUtils.isNotBlank(annName)) {
				env.setAttribute(annName, fieldValue(field));
			} else {
				env.setAttribute(field.getName(), fieldValue(field));
			}

		});
	}

	private final void fieldValue(final Field field, final Object object) {
		try {
			field.set(this, object);
		} catch (IllegalArgumentException | IllegalAccessException e) {
			log.error("Error setting field " + field.getName(), e);
			throw new RuntimeException(e);
		}
	}

	private Object fieldValue(final Field field) {
		try {
			return field.get(this);
		} catch (IllegalArgumentException | IllegalAccessException e) {
			log.error("Error getting field " + field.getName(), e);
			throw new RuntimeException(e);
		}
	}

	public String getBeanName() {
		return this.beanName;
	}

	@Override
	public void setBeanName(final String beanName) {
		this.beanName = beanName;
	}

	public String getNodeName() {
		return this.nodeName;
	}

	public void setNodeName(final String nodeName) {
		this.nodeName = nodeName;
	}

	@Override
	public String toString() {
		return String.format("[node beanName=%s, name=%s]", this.beanName, this.nodeName);
	}

	private final Set<Field> findFields(final Class<?> clazz, final Class<? extends Annotation> ann) {
		final Set<Field> fields = new HashSet<>();
		if (clazz != null) {
			fields.addAll(findFields(clazz.getSuperclass(), ann));

			for (final Field field : clazz.getDeclaredFields()) {
				if (field.isAnnotationPresent(ann)) {
					fields.add(field);
				}
			}
		}
		return fields;
	}

}