package org.simantics.selectionview;

import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Objects;

import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.common.utils.Functions;
import org.simantics.db.exception.DatabaseException;
import org.simantics.layer0.Layer0;

public abstract class AbstractTabContribution<T> implements TabContribution<T> {

    protected final Resource configuration;
    protected final String uri;

    public AbstractTabContribution(ReadGraph graph, Resource configuration) throws DatabaseException {
        this.configuration = Objects.requireNonNull(configuration);
        this.uri = graph.getURI(configuration);
    }

    @Override
    public boolean accept(ReadGraph graph, Object input) throws DatabaseException {
        SelectionViewResources SEL = SelectionViewResources.getInstance(graph);
        // Lets see if multi or single support
        Boolean multi = graph.getRelatedValue2(configuration, SEL.TabContribution_Multi, Bindings.BOOLEAN);
        if (input instanceof Collection<?>) {
            Collection<?> inputs = (Collection<?>) input;
            if (inputs.isEmpty())
                return false;
            if (inputs.size() > 1 && !multi)
                return false;
        } else if (input.getClass().isArray()) {
            int arrayLength = Array.getLength(input);
            if (arrayLength == 0)
                return false;
            if (arrayLength > 1 && !multi)
                return false;
        }
        // HasTest seems to be deprecated but lets support it just for fun
        for(Resource r : graph.getObjects(configuration, SEL.TabContribution_HasTest)) {
            Boolean pass = Functions.exec(graph, r, graph, input);
            if(!pass)
                return false;
        }
        return true;
    }
    
    public abstract void getContributors(ReadGraph graph, T input, Integer priority, String label, Collection<ComparableTabContributor> result) throws DatabaseException;

    @Override
    public final void contribute(ReadGraph graph, T input, Collection<ComparableTabContributor> result) throws DatabaseException {
        Layer0 L0 = Layer0.getInstance(graph);
        SelectionViewResources SEL = SelectionViewResources.getInstance(graph);

        Integer priority = graph.getPossibleRelatedValue(configuration, SEL.TabContribution_HasPriority, Bindings.INTEGER);
        String label = graph.getPossibleRelatedValue(configuration, L0.HasLabel);
        
        getContributors(graph, input, priority, label, result);
    }
    
    @Override
    public String toString() {
        return getClass().getSimpleName() + "[" + uri + "]";
    }
}