package processing.mode.java;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.io.StringWriter;
import java.util.Optional;

import processing.app.Preferences;
import processing.app.SketchException;
import processing.mode.java.preproc.PdePreprocessor;
import processing.mode.java.preproc.PreprocessorResult;
import processing.mode.java.preproc.PdePreprocessIssueException;


public class ProcessingTestUtil {
  static void init() {
    // noop; just causes class to be loaded
  }

  private static final String RESOURCES = "test/resources/";
  private static final String RESOURCES_UP_DIR = "../java/test/resources";
  static final UTCompiler COMPILER;

  static {
    try {
      COMPILER = new UTCompiler(new File("bin-test"), new File("../core/bin"));
      Preferences.load(new FileInputStream(res("preferences.txt")));
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
    //System.err.println("ProcessingTestUtil initialized.");
  }

  static String normalize(final Object s) {
    return String.valueOf(s).replace("\r", "");
  }

  static String preprocess(final String name, final File resource)
      throws SketchException {
    return preprocess(name, resource, Optional.empty());
  }
  static String preprocess(final String name, final File resource, Optional<String> optionalPackage)
      throws SketchException {

    final String program = read(resource);
    final StringWriter out = new StringWriter();

    PdePreprocessor.PdePreprocessorBuilder builder = PdePreprocessor.builderFor(name);
    builder.setTabSize(4);
    builder.setIsTesting(true);

    if (optionalPackage.isPresent()) {
      builder.setDestinationPackage(optionalPackage.get());
    }

    PdePreprocessor preprocessor = builder.build();

    PreprocessorResult result = preprocessor.write(out, program);

    if (result.getPreprocessIssues().size() > 0) {
      throw new PdePreprocessIssueException(result.getPreprocessIssues().get(0));
    }

    return normalize(out);
  }

  static String format(final File resource)
  {
    Preferences.skipInit();
    return format(read(resource));
  }

  static String format(final String programText) {
    return normalize(new AutoFormat().format(programText));
  }

  static File res(final String resourceName) {
    File target = new File(RESOURCES, resourceName);
    if (target.exists()) {
      return target;
    }
    return new File(RESOURCES_UP_DIR, resourceName);
  }

  static String read(final File f) {
    try {
      final FileInputStream fin = new FileInputStream(f);
      final InputStreamReader in = new InputStreamReader(fin, "UTF-8");
      try {
        final StringBuilder sb = new StringBuilder();
        final char[] buf = new char[1 << 12];
        int len;
        while ((len = in.read(buf)) != -1)
          sb.append(buf, 0, len);
        return normalize(sb);
      } finally {
        in.close();
      }
    } catch (Exception e) {
      throw new RuntimeException("Unexpected", e);
    }
  }

}