package org.wamblee.xmlrouter.impl;

import java.util.ArrayList;
import java.util.List;

import org.wamblee.xmlrouter.config.Transformation;

public class TransformationPath {

    private List<Transformation> transformations;

    public TransformationPath() {
        transformations = new ArrayList<Transformation>();
    }

    public TransformationPath(Transformation aTransformation) {
        this();
        transformations.add(aTransformation);
    }

    public TransformationPath(List<Transformation> aTransformations) {
        this();
        transformations.addAll(aTransformations);
    }

    public TransformationPath appendPath(TransformationPath aSequence) {
        if (transformations.isEmpty()) {
            return new TransformationPath(aSequence.transformations);
        }
        if (aSequence.transformations.isEmpty()) {
            // nothing to append
            return new TransformationPath(transformations);
        }
        // both are non-empty
        if (!getToType().equals(aSequence.getFromType())) {
            throw new RuntimeException(
                "error concatening sequence, destination of first differs from source of second");
        }
        List<Transformation> t = new ArrayList<Transformation>(transformations);
        t.addAll(aSequence.transformations);
        return new TransformationPath(t);
    }

    public int size() {
        return transformations.size();
    }

    public String getFromType() {
        if (transformations.isEmpty()) {
            return null;
        }
        return transformations.get(0).getFromType();
    }

    public String getToType() {
        if (transformations.isEmpty()) {
            return null;
        }
        return transformations.get(transformations.size() - 1).getToType();
    }

    public List<Transformation> getTransformations() {
        return transformations;
    }

    @Override
    public String toString() {
        StringBuffer buf = new StringBuffer();
        buf.append("TransformationPath(");
        for (int i = 0; i < transformations.size(); i++) {
            if (i > 0) {
                buf.append(", ");
            }
            buf.append(transformations.get(i).toString());
        }
        buf.append(")");
        return buf.toString();
    }
}