/branch/EclipseFormatter_1.6/src/java/krasa/formatter/eclipse/JavaCodeFormatterFacade.java

package krasa.formatter.eclipse;



import krasa.formatter.plugin.Notifier;

import org.eclipse.jdt.core.ToolFactory;

import org.eclipse.jdt.core.formatter.CodeFormatter;

import org.eclipse.jface.text.BadLocationException;

import org.eclipse.jface.text.Document;

import org.eclipse.jface.text.IDocument;

import org.eclipse.text.edits.TextEdit;



import java.io.File;

import java.util.Properties;



/**

 * @author Vojtech Krasa

 */

public class JavaCodeFormatterFacade extends CodeFormatterFacade {

    protected final String pathToConfigFile;

    protected CodeFormatter codeFormatter;

    private long lastModified;



    public JavaCodeFormatterFacade(String pathToConfigFile) {

        this.pathToConfigFile = pathToConfigFile;

    }



    private CodeFormatter getCodeFormatter() throws InvalidPathToConfigFileException {

        File file = checkIfExists(this.pathToConfigFile);



        if (codeFormatter == null || configFileWasChanged(file)) {

            return newCodeFormatter(file);

        }

        return codeFormatter;

    }



    private CodeFormatter newCodeFormatter(File file) throws InvalidPathToConfigFileException {

        lastModified = file.lastModified();

        Properties properties = readConfig(file);



        if (properties.isEmpty()) {

            throw new InvalidPathToConfigFileException("incorrect properties file");

        }



        codeFormatter = ToolFactory.createCodeFormatter(properties);

        return codeFormatter;

    }



    private boolean configFileWasChanged(File file) {

        return file.lastModified() > lastModified;

    }



    protected String formatInternal(String text, int startOffset, int endOffset, String lineSeparator) throws InvalidPathToConfigFileException {

        if (endOffset > text.length()) {

            endOffset = text.length();

        }

        IDocument doc = new Document();

        try {

            doc.set(text);

            /**

             * Format <code>source</code>,

             * and returns a text edit that correspond to the difference between the given

             * string and the formatted string.

             * <p>

             * It returns null if the given string cannot be formatted.

             * </p><p>

             * If the offset position is matching a whitespace, the result can include

             * whitespaces. It would be up to the caller to get rid of preceding

             * whitespaces.

             * </p>

             *

             * @param kind Use to specify the kind of the code snippet to format. It can

             * be any of these:

             * <ul>

             * 	<li>{@link #K_EXPRESSION}</li>

             * 	<li>{@link #K_STATEMENTS}</li>

             * 	<li>{@link #K_CLASS_BODY_DECLARATIONS}</li>

             * 	<li>{@link #K_COMPILATION_UNIT}<br>

             * 		<b>Since 3.4</b>, the comments can be formatted on the fly while

             * 		using this kind of code snippet<br>

             * 		(see {@link #F_INCLUDE_COMMENTS} for more detailed explanation on

             * 		this flag)

             * 	</li>

             * 	<li>{@link #K_UNKNOWN}</li>

             * 	<li>{@link #K_SINGLE_LINE_COMMENT}</li>

             * 	<li>{@link #K_MULTI_LINE_COMMENT}</li>

             * 	<li>{@link #K_JAVA_DOC}</li>

             * </ul>

             * @param source the source to format

             * @param offset the given offset to start recording the edits (inclusive).

             * @param length the given length to stop recording the edits (exclusive).

             * @param indentationLevel the initial indentation level, used

             *      to shift left/right the entire source fragment. An initial indentation

             *      level of zero or below has no effect.

             * @param lineSeparator the line separator to use in formatted source,

             *     if set to <code>null</code>, then the platform default one will be used.

             * @return the text edit

             * @throws IllegalArgumentException if offset is lower than 0, length is lower than 0 or

             * length is greater than source length.

             */



            TextEdit edit = getCodeFormatter().format(CodeFormatter.K_COMPILATION_UNIT | CodeFormatter.F_INCLUDE_COMMENTS, text,

                    startOffset, endOffset - startOffset, 0, lineSeparator);

            if (edit != null) {

                edit.apply(doc);

            } else {

                throw new RuntimeException(Notifier.FORMATTING_FAILED_PROBABLY_DUE_TO_NOT_COMPILABLE_CODE_OR_WRONG_CONFIG_FILE);

            }

            return doc.get();

        } catch (BadLocationException e) {

            throw new RuntimeException(e);

        }

    }



    @Override

    protected Properties createDefaultConfig() {

        Properties defaultConfig = new Properties();

        // TODO: Ideally, the IntelliJ project's language level should be the default value.

        defaultConfig.setProperty("org.eclipse.jdt.core.compiler.source", "1.5");

        return defaultConfig;

    }



    @Override

    protected void validateConfig(Properties config) {

        String sourceVersionString = config.getProperty("org.eclipse.jdt.core.compiler.source");

        if (sourceVersionString != null) {

            float sourceVersion = 0;

            try {

                sourceVersion = Float.parseFloat(sourceVersionString);

            } catch (NumberFormatException e) {

                throw new RuntimeException("Illegal value for org.eclipse.jdt.core.compiler.source property ("

                        + sourceVersionString + ") - supported Java source versions are 1.5, 1.6, 1.7, or 1.8.");

            }

            if (sourceVersion < 1.5) {

                throw new RuntimeException("Illegal value for org.eclipse.jdt.core.compiler.source property ("

                        + sourceVersionString + ") - Eclipse formatter requires a Java source version >= 1.5.");

            }

        }

    }

}