package org.maltparser.core.flow.item;

import org.maltparser.core.exception.MaltChainedException;
import org.maltparser.core.flow.FlowChartInstance;
import org.maltparser.core.flow.spec.ChartItemSpecification;
import org.maltparser.core.flow.system.elem.ChartElement;

/**
 *
 *
 * @author Johan Hall
 */
public abstract class ChartItem {

    protected FlowChartInstance flowChartinstance;
    protected ChartItemSpecification chartItemSpecification;
    // Signals
    public final static int CONTINUE = 1;
    public final static int TERMINATE = 2;
    public final static int NEWITERATION = 3;

    public ChartItem() {
    }

    /**
     * Initialize the chart item
     *
     * @param flowChartinstance the flow chart instance that the chart item
     * belongs to
     * @param chartItemSpecification a specification of the chart item
     * @throws MaltChainedException
     */
    public void initialize(FlowChartInstance flowChartinstance, ChartItemSpecification chartItemSpecification) throws MaltChainedException {
        setFlowChartInstance(flowChartinstance);
        setChartItemSpecification(chartItemSpecification);
    }

    /**
     * Cause the chart item to perform the preprocess tasks
     *
     * @param signal returned by the previous chart item
     * @return true if every thing is ok, otherwise false
     * @throws MaltChainedException
     */
    public abstract int preprocess(int signal) throws MaltChainedException;

    /**
     * Cause the chart item to perform the process task (for every sentence)
     *
     * @param signal returned by the previous chart item
     * @return true if it is ready to perform the next sentence, otherwise false
     * @throws MaltChainedException
     */
    public abstract int process(int signal) throws MaltChainedException;

    /**
     * Cause the chart item to perform the postprocess tasks
     *
     * @param signal returned by the previous chart item
     * @return true if every thing is ok, otherwise false
     * @throws MaltChainedException
     */
    public abstract int postprocess(int signal) throws MaltChainedException;

    /**
     * Terminates and cleans up the chart item
     *
     * @throws MaltChainedException
     */
    public abstract void terminate() throws MaltChainedException;

    /**
     * Returns the flow chart instance that the chart item belongs to
     *
     * @return the flow chart instance that the chart item belongs to
     */
    public FlowChartInstance getFlowChartInstance() {
        return flowChartinstance;
    }

    /**
     * Sets the flow chart instance that the chart item belongs to
     *
     * @param flowChartinstance a flow chart instance
     */
    protected void setFlowChartInstance(FlowChartInstance flowChartinstance) {
        this.flowChartinstance = flowChartinstance;
    }

    /**
     * Returns the option container index
     *
     * @return the option container index
     */
    public int getOptionContainerIndex() {
        return flowChartinstance.getOptionContainerIndex();
    }

    /**
     * Returns the chart element in the flow chart system description
     *
     * @param key a chart element key
     * @return the chart element in the flow chart system description
     */
    public ChartElement getChartElement(String key) {
        return flowChartinstance.getFlowChartManager().getFlowChartSystem().getChartElement(key);
    }

    /**
     * Returns a chart item specification
     *
     * @return a chart item specification
     */
    public ChartItemSpecification getChartItemSpecification() {
        return chartItemSpecification;
    }

    /**
     * Sets the specification of the chart item
     *
     * @param chartItemSpecification a chart item specification
     */
    public void setChartItemSpecification(ChartItemSpecification chartItemSpecification) {
        this.chartItemSpecification = chartItemSpecification;
    }
}