TemplatesUtils.java

package name.admitriev.jhelper.generation;

import com.intellij.openapi.editor.Document;
import com.intellij.openapi.fileEditor.FileDocumentManager;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.psi.PsiFile;
import com.intellij.psi.PsiManager;
import name.admitriev.jhelper.exceptions.JHelperException;
import name.admitriev.jhelper.exceptions.NotificationException;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Utility class for customizing templates of code
 */
public class TemplatesUtils {

	public static final Pattern CLASS_NAME = Pattern.compile("%ClassName%", Pattern.LITERAL);
	public static final Pattern TASK_FILE = Pattern.compile("%TaskFile%", Pattern.LITERAL);
	public static final Pattern TESTS = Pattern.compile("%Tests%", Pattern.LITERAL);
	public static final Pattern SOLVER_CALL = Pattern.compile("%SolverCall%", Pattern.LITERAL);
	public static final Pattern INPUT = Pattern.compile("%Input%", Pattern.LITERAL);
	public static final Pattern OUTPUT = Pattern.compile("%Output%", Pattern.LITERAL);
	public static final Pattern CODE = Pattern.compile("%Code%", Pattern.LITERAL);

	private TemplatesUtils() {
	}

	public static String replaceAll(String text, Pattern pattern, String replacement) {
		return pattern.matcher(text).replaceAll(Matcher.quoteReplacement(replacement));
	}

	public static String getTemplate(Project project, String name) {
		String filename = name + ".template";
		VirtualFile file = project.getBaseDir().findFileByRelativePath(filename);
		if (file == null) {
			createTemplateFromDefault(project, name);
			file = project.getBaseDir().findFileByRelativePath(filename);
			if (file == null) {
				throw new JHelperException("Can't open template file(" + filename + ") after its creation");
			}

		}
		Document document = FileDocumentManager.getInstance().getDocument(file);
		if (document == null) {
			throw new NotificationException("Couldn't find template \"" + name + '"');
		}

		return document.getText();
	}

	private static void createTemplateFromDefault(Project project, String name) {
		String filename = name + ".template";
		VirtualFile file = FileUtils.findOrCreateByRelativePath(project.getBaseDir(), filename);
		PsiFile psiFile = PsiManager.getInstance(project).findFile(file);
		String defaultTemplate;
		try {
			defaultTemplate = getResourceContent("/name/admitriev/jhelper/templates/" + filename);
		}
		catch (IOException e) {
			throw new NotificationException("Couldn't open default template " + filename, e);
		}

		FileUtils.writeToFile(psiFile, defaultTemplate);
	}

	/**
	 * Returns content of resource file (from resource folder) as a string.
	 */
	private static String getResourceContent(String name) throws IOException {
		try (InputStream stream = TemplatesUtils.class.getResourceAsStream(name)) {
			if (stream == null) {
				throw new IOException("Couldn't open a stream to resource " + name);
			}
			try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream, "UTF-8"))) {
				StringBuilder sb = new StringBuilder();
				String line;
				//noinspection NestedAssignment
				while ((line = reader.readLine()) != null) {
					sb.append(line).append('\n');
				}
				return sb.toString();
			}
		}
	}

}