/*******************************************************************************

* Any modification, copies of sections of this file must be attached with this

* license and shown clearly in the developer's project. The code can be used

* as long as you state clearly you do not own it. Any violation might result in

* a take-down.

*

* MIT License

*

* Copyright (c) 2016, 2017 Anthony Law

*

* Permission is hereby granted, free of charge, to any person obtaining a copy

* of this software and associated documentation files (the "Software"), to deal

* in the Software without restriction, including without limitation the rights

* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

* copies of the Software, and to permit persons to whom the Software is

* furnished to do so, subject to the following conditions:

*

* The above copyright notice and this permission notice shall be included in all

* copies or substantial portions of the Software.

*

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

* SOFTWARE.

*******************************************************************************/

package org.ev3dev.io;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintWriter;

import java.util.ArrayList;

import java.util.List;

/***

* A class for reading/writing to the EV3 driver system classes

* @author Anthony

*

*/

public class Sysfs {

/**

* The default ev3dev Sysfs class path (/sys/class/)

*/

public static final String DEFAULT_SYSTEM_CLASS_PATH = "/sys/class/";

private static String SYSTEM_CLASS_PATH = DEFAULT_SYSTEM_CLASS_PATH;

private static boolean incompat_check = true;

/**

* Sets the library incompatibility check to be enabled or not

* @param enabled Enabled

*/

public static void setIncompatibleCheckEnabled(boolean enabled){

incompat_check = enabled;

}

/**

* Returns whether the library incompatibility check is enabled or not

* @param enabled Enabled

*/

public static boolean isIncompatibleCheckEnabled(){

return incompat_check;

}

/**

* Get all sub-class files

* @param class_name Main Class Name

* @return File Array

*/

public static File[] getAllSubClass(String class_name){

File file = new File(SYSTEM_CLASS_PATH + class_name);

File[] files = file.listFiles();

return files;

}

/**

* Returns the current ev3dev Sysfs path.

* @return the current Sysfs path

*/

public static String getSysfsPath(){

return SYSTEM_CLASS_PATH;

}

/**

* Modify the current ev3dev Sysfs path in this library instance to be used. This is probably used for debugging purpose. Any invalid modification to the path will break the library.

* @param path The file-system path to be used

*/

public static void setSysfsPath(String path){

SYSTEM_CLASS_PATH = path;

}

/**

* Sets the current ev3dev Sysfs path to default

*/

public static void resetSysfsPath(){

SYSTEM_CLASS_PATH = DEFAULT_SYSTEM_CLASS_PATH;

}

/***

* Reads the property of the class specified.

* @param class_name The class name

* @param property The property name of the class.

* @return The value of the property

* @throws FileNotFoundException If the specified class isn't exist.

* @throws IOException If the API couldn't read the class's property

*/

public static String getAttribute(String class_name, String property) throws FileNotFoundException, IOException{

File file = new File(SYSTEM_CLASS_PATH + class_name + "/" + property);

class_name = class_name.toLowerCase();

property = property.toLowerCase();

FileInputStream in = new FileInputStream(file);

StringBuilder sb = new StringBuilder();

BufferedReader br = null;

String line;

try {

br = new BufferedReader(new InputStreamReader(in));

while ((line = br.readLine()) != null) {

sb.append(line);

}

} catch (IOException e) {

throw e;

} finally {

if (br != null) {

try {

br.close();

} catch (IOException e) {

throw e;

}

}

}

return sb.toString();

}

/***

* Reads the property of the class and subclass specified.

* @param class_name The class name.

* @param subclass The Sub-class name.

* @param property The property name of the class

* @return The value of the property

* @throws FileNotFoundException If the specified class isn't exist.

* @throws IOException If the API couldn't read the class's property

*/

public static String getAttribute(String class_name, String subclass, String property) throws FileNotFoundException, IOException{

return getAttribute(class_name, subclass + "/" + property);

}

/***

* Writes the property of the class and subclass specified.

* @param class_name The class name.

* @param subclass The Sub-class name.

* @param property The property name of the class

* @param new_value The new value of the property

* @throws FileNotFoundException If the specified class isn't exist.

* @throws IOException If the API couldn't read the class's property

*/

public static void setAttribute(String class_name, String subclass, String property, String new_value) throws FileNotFoundException, IOException{

setAttribute(class_name, subclass + "/" + property, new_value);

}

/***

* Writes the property of the class specified.

* @param class_name The class name.

* @param property The property name of the class

* @param new_value The new value of the property

* @throws FileNotFoundException If the specified class isn't exist.

* @throws IOException If the API couldn't read the class's property

*/

public static void setAttribute(String class_name, String property, String new_value) throws FileNotFoundException, IOException{

PrintWriter out = new PrintWriter(SYSTEM_CLASS_PATH + class_name + "/" + property);

out.write(new_value);

out.flush();

out.close();

}

/***

* A function to separate space from a spaced-array.

* @param space_array A string

* @return A array of the string/space-array

*/

public static String[] separateSpace(String space_array){

int i;

int j;

String sep;

List<String> list = new ArrayList<String>(50);

for (i = 0; i < space_array.length(); i++){

for (j = i; j < space_array.length(); j++){

if (space_array.charAt(j) == ' '){

break;

}

}

if (j == space_array.length()){

break;

}

sep = space_array.substring(i, j + 1);

list.add(sep);

i = j;

}

Object[] objarr = list.toArray();

String[] strarr = new String[objarr.length];

for (i = 0; i < strarr.length; i++){

strarr[i] = (String) objarr[i];

}

return strarr;

}

private static String readFile(File file) throws IOException{

FileInputStream in = new FileInputStream(file);

StringBuilder sb = new StringBuilder();

BufferedReader br = null;

String line;

try {

br = new BufferedReader(new InputStreamReader(in));

while ((line = br.readLine()) != null) {

sb.append(line);

}

} catch (IOException e) {

throw e;

} finally {

if (br != null) {

try {

br.close();

} catch (IOException e) {

throw e;

}

}

}

return sb.toString();

}

/**

* Search the full class name, using a class name, FS folder prefix and an address

* @param classname The class Name (e.g. lego-port, tacho-motor)

* @param fsFolderPrefix The FS folder prefix, without the value [N] (e.g. motor, sensor)

* @param address Port address (e.g. outA, in1)

* @return The full FS class folder name, with the same port address, if none, returns null

*/

public static String searchClassFullName(String classname, String fsFolderPrefix, String address){

File[] sub = Sysfs.getAllSubClass(classname);

File file;

String data;

for (File asub : sub){

file = new File(asub.getAbsolutePath() + "/address");

try {

data = readFile(file);

if(data.equals(address)){

return asub.getName();

}

} catch (Exception ignore){}

}

return null;

}

}