package auxtestlib;
   
   import java.io.ByteArrayOutputStream;
   import java.io.File;
   import java.io.FileInputStream;
   import java.io.FileOutputStream;
   import java.io.FileReader;
   import java.io.FileWriter;
   import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  
  /**
   * Utility class with methods to help dealing with text files.
   */
  public final class FileContentWorker {
  	/**
  	 * Utility class: no constructor.
  	 */
  	private FileContentWorker() {
  		/*
  		 * Nothing to do.
  		 */
  	}
  	
  	/**
  	 * Reads a file's contents.
  	 * @param file the file
  	 * @return a string with the whole file's contents
  	 * @throws IOException failed to read the file
  	 */
  	public static String read_contents(File file) throws IOException {
  		if (file == null) {
  			throw new IllegalArgumentException("file == null");
  		}
  
  		StringBuffer sb = new StringBuffer();
  		try (FileReader fr = new FileReader(file)) {
  			int ch;
  			while ((ch = fr.read()) != -1) {
  				sb.append((char) ch);
  			}
  		}
  
  		return sb.toString();
  	}
  
  	/**
  	 * Obtains the contents of a file as a binary array.
  	 * @param binFile the file
  	 * @return an array with the file's contents
  	 * @throws IOException failed to read the file
  	 */
  	public static byte[] read_contents_bin(File binFile) throws IOException {
  		if (binFile == null) {
  			throw new IllegalArgumentException("binFile == null");
  		}
  
  		ByteArrayOutputStream os = new ByteArrayOutputStream();
  		try (FileInputStream fis = new FileInputStream(binFile)) {
  			int ch;
  			while ((ch = fis.read()) != -1) {
  				os.write(ch);
  			}
  		}
  
  		return os.toByteArray();
  	}
  	
  	/**
  	 * Changes the contents of a file (or creates a new file if it doesn't
  	 * exist).
  	 * @param f the file to change
  	 * @param s the file's new contents
  	 * @throws IOException failed to write the file
  	 */
  	public static void set_contents(File f, String s) throws IOException {
  		if (f == null) {
  			throw new IllegalArgumentException("f == null");
  		}
  
  		if (s == null) {
  			throw new IllegalArgumentException("s == null");
  		}
  
  		try (FileWriter fw = new FileWriter(f)) {
  			fw.write(s);
  		}
  	}
  	
  	/**
  	 * Changes the contents of a file (or creates a new file if it doesn't
  	 * exist).
  	 * @param f the file to change
  	 * @param data the new file's contents
  	 * @throws IOException failed to write the file
  	 */
  	public static void set_contents_bin(File f, byte data[])
  			throws IOException {
 		if (f == null) {
 			throw new IllegalArgumentException("f == null");
 		}
 
 		if (data == null) {
 			throw new IllegalArgumentException("data == null");
 		}
 
 		try (FileOutputStream fo = new FileOutputStream(f)) {
 			fo.write(data);
 		}
 	}
 	
 	/**
 	 * Reads a file's contents (the file is expected to be a resource).
 	 * @param name the resource name
 	 * @return the resource's contents as a string
 	 * @throws IOException failed to read the resource
 	 */
 	public static String read_resource(String name) throws IOException {
 		if (name == null) {
 			throw new IllegalArgumentException("name == null");
 		}
 
 		StringBuffer sb = new StringBuffer();
 		try (InputStream is =
 				FileContentWorker.class.getResourceAsStream(name)) {
 			if (is == null) {
 				throw new IllegalArgumentException("Resource '" + name + "' "
 						+ "is not available.");
 			}
 	
 			try (InputStreamReader isr = new InputStreamReader(is)) {
 				int ch;
 				while ((ch = isr.read()) != -1) {
 					sb.append((char) ch);
 				}
 			}
 		}
 		
 		return sb.toString();
 	}
 
 	/**
 	 * Reads a file's contents (the file is expected to be a resource).
 	 * @param cls a class defining the package where the resource is located
 	 * @param name the resource name
 	 * @return the resource's contents as a string
 	 * @throws IOException failed to read the resource
 	 */
 	public static String read_resource(Class<?> cls, String name)
 			throws IOException {
 		if (cls == null) {
 			throw new IllegalArgumentException("cls == null");
 		}
 		
 		if (name == null) {
 			throw new IllegalArgumentException("name == null");
 		}
 
 		StringBuffer sb = new StringBuffer();
 		try (InputStream is = cls.getResourceAsStream(name)) {
 			if (is == null) {
 				throw new IllegalArgumentException("Resource '" + name + "' "
 						+ "is not available.");
 			}
 	
 			try (InputStreamReader isr = new InputStreamReader(is)) {
 				int ch;
 				while ((ch = isr.read()) != -1) {
 					sb.append((char) ch);
 				}
 			}
 		}
 		
 		return sb.toString();
 	}
 	
 	/**
 	 * Reads a file's contents as binary data (the file is expected to be a
 	 * resource).
 	 * @param name the resource name
 	 * @return the resource's contents
 	 * @throws IOException failed to read the resource
 	 */
 	public static byte[] read_resource_bin(String name)
 			throws IOException {
 		if (name == null) {
 			throw new IllegalArgumentException("name == null");
 		}
 
 		ByteArrayOutputStream os = new ByteArrayOutputStream();
 		try (InputStream is =
 				FileContentWorker.class.getResourceAsStream(name)) {
 			if (is == null) {
 				throw new IllegalArgumentException("Resource '" + name + "' is "
 						+ "not available.");
 			}
 	
 			int ch;
 			while ((ch = is.read()) != -1) {
 				os.write(ch);
 			}
 		}
 		
 		return os.toByteArray();
 	}
 	
 	/**
 	 * Checks that two files are equal.
 	 * @param f1 first file
 	 * @param f2 second file
 	 * @return are the files equal?
 	 * @throws IOException failed to read the files
 	 */
 	public static boolean files_equal(File f1, File f2) throws IOException {
 		if (f1 == null) {
 			throw new IllegalArgumentException("f1 == null");
 		}
 
 		if (f2 == null) {
 			throw new IllegalArgumentException("f2 == null");
 		}
 
 		byte dt1[] = FileContentWorker.read_contents_bin(f1);
 		byte dt2[] = FileContentWorker.read_contents_bin(f2);
 		return ComparisonUtils.array_equals(dt1, dt2);
 	}
 }