DirectorySourceLocator.java

/*
 * Copyright 2010 Henry Coles
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and limitations under the License.
 */
package org.pitest.mutationtest.tooling;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.Reader;
import java.util.Collection;
import java.util.List;

import org.pitest.functional.F;
import org.pitest.functional.FCollection;
import org.pitest.functional.Option;
import org.pitest.mutationtest.SourceLocator;

public class DirectorySourceLocator implements SourceLocator {

  private final File                    root;
  private final F<File, Option<Reader>> fileToReader;

  private static class FileToReader implements F<File, Option<Reader>> {

    @Override
    public Option<Reader> apply(final File f) {
      if (f.exists()) {
        try {
          return Option.<Reader> some(new FileReader(f));
        } catch (final FileNotFoundException e) {
          return Option.none();
        }
      }
      return Option.none();
    }

  };

  DirectorySourceLocator(final File root,
      final F<File, Option<Reader>> fileToReader) {
    this.root = root;
    this.fileToReader = fileToReader;
  }

  public DirectorySourceLocator(final File root) {
    this(root, new FileToReader());
  }

  @Override
  public Option<Reader> locate(final Collection<String> classes,
      final String fileName) {
    final List<Reader> matches = FCollection.flatMap(classes,
        classNameToSourceFileReader(fileName));
    if (matches.isEmpty()) {
      return Option.none();
    } else {
      return Option.some(matches.iterator().next());
    }
  }

  private F<String, Iterable<Reader>> classNameToSourceFileReader(
      final String fileName) {
    return new F<String, Iterable<Reader>>() {

      @Override
      public Iterable<Reader> apply(final String className) {
        if (className.contains(".")) {
          final File f = new File(className.replace(".", File.separator));
          return locate(f.getParent() + File.separator + fileName);
        } else {
          return locate(fileName);
        }
      }

    };
  }

  private Option<Reader> locate(final String fileName) {
    final File f = new File(this.root + File.separator + fileName);
    return this.fileToReader.apply(f);
  }

}