package org.andromda.core.cartridge.template;

import java.io.File;
import org.andromda.core.cartridge.Resource;
import org.andromda.core.common.XmlObjectFactory;
import org.andromda.core.metafacade.MetafacadeConstants;
import org.apache.commons.lang.StringUtils;

/**
 * This class implements the <code>&lt;template&gt;</code> tag in a cartridge
 * descriptor file.
 *
 * @author <a href="http://www.mbohlen.de">Matthias Bohlen </a>
 * @author Anthony Mowers
 * @author Chad Brandon
 * @author Bob Fields
 */
public class Template
    extends Resource
{
    /**
     * The default constructor used by the {@link XmlObjectFactory} to instantiate the template configuration.
     */
    public Template()
    {
        this.supportedModelElements = new ModelElements();
    }

    /**
     * A flag indicating whether or not empty files should
     * be generated.
     */
    private boolean generateEmptyFiles = false;

    /**
     * Tells us whether output files should be generated if this template does not produce any output.
     *
     * @param generateEmptyFiles generate files for empty output yes/no
     */
    public void setGenerateEmptyFiles(final boolean generateEmptyFiles)
    {
        this.generateEmptyFiles = generateEmptyFiles;
    }

    /**
     * Tells us whether output files are generated by this template if the template produces empty output.
     *
     * @return boolean
     */
    public boolean isGenerateEmptyFiles()
    {
        return generateEmptyFiles;
    }

    /**
     * Returns the fully qualified output file, this means:
     * <ul>
     * <li>the output pattern has been translated</li>
     * <li>the output dir name has been prepended</li>
     * </ul>
     *
     * @param metafacadeName name of the metafacade.
     * @param packageName name of the package from the model in which the class
     *        is contained
     * @param directory the directory as a File.
     * @param outputPattern if defined, this overrides the value of {@link Resource#getOutputPattern()}.
     * @return File absolute directory.
     */
    public File getOutputLocation(
        final String metafacadeName,
        final String packageName,
        final File directory,
        String outputPattern)
    {
        File file;

        if (StringUtils.isBlank(outputPattern))
        {
            outputPattern = this.getOutputPattern();
        }
        // - if singleFileOutput is set to true, then
        //   just use the output pattern as the file to
        //   output to, otherwise we replace using message format.
        if (this.isOutputToSingleFile())
        {
            file = super.getOutputLocation(
                    new String[] {outputPattern},
                    directory,
                    outputPattern);
        }
        else
        {
            file =
                super.getOutputLocation(
                    new String[]
                    {
                        StringUtils.replace(
                            StringUtils.trimToEmpty(packageName),
                            MetafacadeConstants.NAMESPACE_SCOPE_OPERATOR,
                            File.separator), metafacadeName
                    },
                    directory,
                    outputPattern);
        }
        return file;
    }

    /**
     * Tells us the model elements that are supported by this template (i.e. will be processed by this template)
     *
     * @return ModelElements all the model elements that should be processed by thsi template
     * @see org.andromda.core.cartridge.template.ModelElements
     */
    public ModelElements getSupportedModeElements()
    {
        final String methodName = "Template.getModelElements";
        if (this.supportedModelElements == null)
        {
            throw new TemplateException(methodName + " - supportedModelElements is null!");
        }
        return this.supportedModelElements;
    }

    /**
     * Sets the model elements that are supported by this template.
     *
     * @param supportedModelElements the ModelElements instance.
     * @see org.andromda.core.cartridge.template.ModelElements
     */
    public void setSupportedModelElements(final ModelElements supportedModelElements)
    {
        this.supportedModelElements = supportedModelElements;
    }

    private boolean outputToSingleFile = false;

    /**
     * If output to single file is <code>true</code> then all model elements found by the processor (i.e. all those
     * having matching modelElements) will aggregated and output to one single file.
     *
     * @return Returns the outputToSingleFile.
     */
    public boolean isOutputToSingleFile()
    {
        return outputToSingleFile;
    }

    /**
     * Sets whether or not we should aggregate elements and output to a single file.
     *
     * @param outputToSingleFile The outputToSingleFile to set.
     */
    public void setOutputToSingleFile(final boolean outputToSingleFile)
    {
        this.outputToSingleFile = outputToSingleFile;
    }

    /**
     * Indicates whether or not files should be output when there are no elements when aggregating.
     */
    private boolean outputOnEmptyElements = true;

    /**
     * Indicates that when there are no elements in the collection of elements (when {@link #isOutputToSingleFile()} is
     * <code>true</code>, whether or not the file should be output.  Default is <code>true</code>
     *
     * @return true/false
     * @see #isOutputToSingleFile()
     */
    public boolean isOutputOnEmptyElements()
    {
        return this.outputOnEmptyElements;
    }

    /**
     * Sets whether or not we should output a file when no elements exist in the collection of elements when {@link
     * #isOutputToSingleFile()} returns <code>true</code>.
     *
     * @param outputOnEmptyElements the boolean flag.
     * @see #isOutputOnEmptyElements()
     * @see #isOutputToSingleFile()
     */
    public void setOutputOnEmptyElements(final boolean outputOnEmptyElements)
    {
        this.outputOnEmptyElements = outputOnEmptyElements;
    }

    /**
     * @see Object#toString()
     */
    @Override
    public String toString()
    {
        StringBuilder builder = new StringBuilder();
        builder.append(super.toString());
        builder.append(" [generateEmptyFiles=").append(this.generateEmptyFiles);
        builder.append(", outputToSingleFile=").append(this.outputToSingleFile);
        builder.append(", outputOnEmptyElements=").append(this.outputOnEmptyElements);
        builder.append(", supportedModelElements=").append(this.supportedModelElements);
        builder.append("]");
        return builder.toString();
    }

    /**
     * The model elements (i.e. metafacades) supported by this template.
     */
    private ModelElements supportedModelElements = null;
}