package calculatorprojecteval;

import java.io.File;

import java.io.FileNotFoundException;

import java.util.ArrayList;

import java.util.Scanner;

import java.lang.*;

/**

*

* @author ParkerC

*/

public class CalculatorProjectEval

{

/**

* @param args the command line arguments

*/

public static void main(String[] args) throws FileNotFoundException

{

// comment out either startCalc() or testCalc() (just the method call below)

// based on how you want to run the project

// use this code to drive your interactive calculator

// add a welcome message here

//startCalc(); // you have to write this method below

// it should ask the user for input and print

// results until the user enters "quit" to stop

// use this to validate your project (the calculator part, anyways)

testCalc(); // testCalc will call a calculate(String s) method that you create

// as part of your overall project. This method will take the user's

// input, and return a String with the appropriate output.

// add a goodbye message here

}

public static void testCalc() throws FileNotFoundException{

ArrayList<String> problems = new ArrayList<>();

ArrayList<String> results = new ArrayList<>();

// load problems from a file

File fProblems = new File("problems.txt");

Scanner sc = new Scanner(fProblems);

int count = 0;

String line = "";

int problemCount = 0;

int resultCount = 0;

while (sc.hasNextLine()){

line = sc.nextLine();

if (!line.startsWith("//") && !line.trim().equals("")){ // ignore comments at the beginning

problems.add(line.substring(3).trim());

problemCount++;

if (sc.hasNextLine()){

line = sc.nextLine();

if (!line.startsWith("//") && !line.trim().equals("")){

results.add(line.substring(3).trim());

resultCount++;

}

}

count++;

}

}

if (problemCount == resultCount){

// now run the tests

for (int i=0; i<problemCount; i++){

String prob = problems.get(i);

String result = calculate(prob);

if (result == null){

System.out.println("FAILED test " + i);

System.out.println("Expression: " + problems.get(i));

System.out.println("Expected result: " + results.get(i));

System.out.println("Actual: null String returned from calculate()");

} else {

if (result.equals(results.get(i))){

System.out.println("PASSED test " + i);

} else {

System.out.println("FAILED test " + i);

System.out.println("Expression: " + problems.get(i));

System.out.println("Expected result: " + results.get(i));

System.out.println("Actual: " + result);

}

}

}

} else {

System.out.println("problem file error");

}

}

public static void startCalc() {

// your code here to get user input, and calculate/print results. You'll call

// the calculate(String s) as part of your code here, which returns a String

// with the result to print.

String input = ReadInput();

if ("quit".equalsIgnoreCase(input)){

System.out.println("E: quit");

return;

}else{

String result = calculate(input);

System.out.println("E: "+ result);

}

}

public static String calculate(String s){

try{

// you add code here to take a String as a parameter, and return a String with the result

String[] tokens = Tokenize(s);

if (tokens == null || tokens.length <= 1){

// Invalid input when there is just one token

throw new Exception("");

}else{

switch (tokens[0]){

case "|":

return ProcessAbsCommand(tokens);

case "v":

return ProcessSqrtCommand(tokens);

}

return "";

}

} catch (Exception e){

return "ERROR";

}

}

public static String ReadInput(){

Scanner scan = new Scanner(System.in);

return scan.next();

}

private static String[] Tokenize(String input){

return input.split(" ");

}

private static String ProcessSqrtCommand(String[] tokens) throws Exception{

if (tokens.length != 2){

throw new Exception("");

}

int num = ParseInt(tokens[1]);

return String.valueOf(Math.sqrt(num));

}

private static String ProcessAbsCommand(String[] tokens) throws Exception{

if (tokens.length != 2){

throw new Exception("");

}

int num = ParseInt(tokens[1]);

return String.valueOf(Math.abs(num));

}

private static int ParseInt(String token) throws Exception{

try{

return Integer.parseInt(token);

}catch (Exception e){

throw new Exception(token);

}

}

}