/**
 * ============LICENSE_START====================================================
 * org.onap.aaf
 * ===========================================================================
 * Copyright (c) 2018 AT&T Intellectual Property. All rights reserved.
 * ===========================================================================
 * 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.
 * ============LICENSE_END====================================================
 *
 */

package org.onap.aaf.auth.batch.helpers;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintStream;
import java.util.Iterator;
import java.util.NoSuchElementException;

public class InputIterator implements Iterable<String> {
    private BufferedReader in;
    private final PrintStream out;
    private final String prompt, instructions;
    
    public InputIterator(BufferedReader in, PrintStream out, String prompt, String instructions) {
        this.in = in;
        this.out = out;
        this.prompt = prompt;
        this.instructions = instructions;
    }
    
    @Override
    public Iterator<String> iterator() {
        out.println(instructions);
        return new Iterator<String>() {
            String input;
            @Override
            public boolean hasNext() {
                out.append(prompt);
                try {
                    input = in.readLine();
                } catch (IOException e) {
                    input = null;
                    return false;
                }
                return input.length()>0;
            }

            @Override
            public String next() {
                if (!hasNext()) {
                    throw new NoSuchElementException();
                }
                return input;
            }

            @Override
            public void remove() {
            }
        };
    }
}