/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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
    *
    *      https://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.apache.commons.net.nntp;
  
  import java.io.PrintStream;
  import java.util.ArrayList;
  import java.util.Collections;
  
  import org.apache.commons.net.util.NetConstants;
  
  /**
   * Basic state needed for message retrieval and threading. With thanks to Jamie Zawinski (jwz@jwz.org)
   */
  public class Article implements Threadable<Article> {
  
      /**
       * Recursive method that traverses a pre-threaded graph (or tree) of connected Article objects and prints them out.
       *
       * @param article the root of the article 'tree'
       * @since 3.4
       */
      public static void printThread(final Article article) {
          printThread(article, 0, System.out);
      }
  
      /**
       * Recursive method that traverses a pre-threaded graph (or tree) of connected Article objects and prints them out.
       *
       * @param article the root of the article 'tree'
       * @param depth   the current tree depth
       */
      public static void printThread(final Article article, final int depth) {
          printThread(article, depth, System.out);
      }
  
      /**
       * Recursive method that traverses a pre-threaded graph (or tree) of connected Article objects and prints them out.
       *
       * @param article the root of the article 'tree'
       * @param depth   the current tree depth
       * @param ps      the PrintStream to use
       * @since 3.4
       */
      public static void printThread(final Article article, final int depth, final PrintStream ps) {
          for (int i = 0; i < depth; ++i) {
              ps.print("==>");
          }
          ps.println(article.getSubject() + "\t" + article.getFrom() + "\t" + article.getArticleId());
          if (article.kid != null) {
              printThread(article.kid, depth + 1);
          }
          if (article.next != null) {
              printThread(article.next, depth);
          }
      }
  
      /**
       * Recursive method that traverses a pre-threaded graph (or tree) of connected Article objects and prints them out.
       *
       * @param article the root of the article 'tree'
       * @param ps      the PrintStream to use
       * @since 3.4
       */
      public static void printThread(final Article article, final PrintStream ps) {
          printThread(article, 0, ps);
      }
  
      private long articleNumber;
      private String subject;
      private String date;
      private String articleId;
  
      private String simplifiedSubject;
  
      private String from;
      private ArrayList<String> references;
  
      private boolean isReply;
  
      /**
       * Will be private in 4.0.
       *
       * @deprecated Use {@link #setChild(Article)} and {@link #getChild()}.
       */
     @Deprecated
     public Article kid;
 
     /**
      * Will be private in 4.0.
      *
      * @deprecated Use {@link #setNext(Article)} and {@link #getNext()}.
      */
     @Deprecated
     public Article next;
 
     /**
      * Constructs a new instance.
      */
     public Article() {
         articleNumber = -1; // isDummy
     }
 
     /**
      * Does nothing.
      *
      * @param name Ignored.
      * @param val  Ignored.
      */
     @Deprecated
     public void addHeaderField(final String name, final String val) {
         // empty
     }
 
     /**
      * Adds a message-id to the list of messages that this message references (i.e. replies to)
      *
      * @param msgId the message id to add
      */
     public void addReference(final String msgId) {
         if (msgId == null || msgId.isEmpty()) {
             return;
         }
         if (references == null) {
             references = new ArrayList<>();
         }
         isReply = true;
         Collections.addAll(references, msgId.split(" "));
     }
 
     private void flushSubjectCache() {
         simplifiedSubject = null;
     }
 
     /**
      * Gets the article ID.
      *
      * @return the article ID.
      */
     public String getArticleId() {
         return articleId;
     }
 
     /**
      * Gets the article number.
      *
      * @return the article number.
      */
     @Deprecated
     public int getArticleNumber() {
         return (int) articleNumber;
     }
 
     /**
      * Gets the article number.
      *
      * @return the article number.
      */
     public long getArticleNumberLong() {
         return articleNumber;
     }
 
     /**
      * Gets the child article.
      *
      * @return the child article.
      * @since 3.12.0
      */
     public Article getChild() {
         return kid;
     }
 
     /**
      * Gets the article date header.
      *
      * @return the article date header.
      */
     public String getDate() {
         return date;
     }
 
     /**
      * Gets the article from header.
      *
      * @return the article from header.
      */
     public String getFrom() {
         return from;
     }
 
     /**
      * Gets the next article.
      *
      * @return the next article.
      * @since 3.12.0
      */
     public Article getNext() {
         return next;
     }
 
     /**
      * Returns the MessageId references as an array of Strings
      *
      * @return an array of message-ids
      */
     public String[] getReferences() {
         if (references == null) {
             return NetConstants.EMPTY_STRING_ARRAY;
         }
         return references.toArray(NetConstants.EMPTY_STRING_ARRAY);
     }
 
     /**
      * Gets the article subject.
      *
      * @return the article subject.
      */
     public String getSubject() {
         return subject;
     }
 
     @Override
     public boolean isDummy() {
         return articleNumber == -1;
     }
 
     @Override
     public Article makeDummy() {
         return new Article();
     }
 
     @Override
     public String messageThreadId() {
         return articleId;
     }
 
     @Override
     public String[] messageThreadReferences() {
         return getReferences();
     }
 
     /**
      * Sets the article ID.
      *
      * @param string the article ID.
      */
     public void setArticleId(final String string) {
         articleId = string;
     }
 
     /**
      * Sets the article number.
      *
      * @param articleNumber  the article number.
      */
     @Deprecated
     public void setArticleNumber(final int articleNumber) {
         this.articleNumber = articleNumber;
     }
 
     /**
      * Sets the article number.
      *
      * @param articleNumber  the article number.
      */
     public void setArticleNumber(final long articleNumber) {
         this.articleNumber = articleNumber;
     }
 
     @Override
     public void setChild(final Article child) {
         this.kid = child;
         flushSubjectCache();
     }
 
     /**
      * Sets the article date header.
      *
      * @param date  the article date header.
      */
     public void setDate(final String date) {
         this.date = date;
     }
 
     /**
      * Sets the article from header.
      *
      * @param from  the article from header.
      */
     public void setFrom(final String from) {
         this.from = from;
     }
 
     @Override
     public void setNext(final Article next) {
         this.next = next;
         flushSubjectCache();
     }
 
     /**
      * Sets the article subject.
      *
      * @param subject  the article subject.
      */
     public void setSubject(final String subject) {
         this.subject = subject;
     }
 
     @Override
     public String simplifiedSubject() {
         if (simplifiedSubject == null) {
             simplifySubject();
         }
         return simplifiedSubject;
     }
 
     /**
      * Attempts to parse the subject line for some typical reply signatures, and strip them out
      */
     private void simplifySubject() {
         int start = 0;
         final String subject = getSubject();
         final int len = subject.length();
 
         boolean done = false;
 
         while (!done) {
             done = true;
 
             // skip whitespace
             // "Re: " breaks this
             while (start < len && subject.charAt(start) == ' ') {
                 start++;
             }
 
             if (start < len - 2 && (subject.charAt(start) == 'r' || subject.charAt(start) == 'R')
                     && (subject.charAt(start + 1) == 'e' || subject.charAt(start + 1) == 'E')) {
 
                 if (subject.charAt(start + 2) == ':') {
                     start += 3; // Skip "Re:"
                     done = false;
                 } else if (start < len - 2 && (subject.charAt(start + 2) == '[' || subject.charAt(start + 2) == '(')) {
 
                     int i = start + 3;
 
                     while (i < len && subject.charAt(i) >= '0' && subject.charAt(i) <= '9') {
                         i++;
                     }
 
                     if (i < len - 1 && (subject.charAt(i) == ']' || subject.charAt(i) == ')') && subject.charAt(i + 1) == ':') {
                         start = i + 2;
                         done = false;
                     }
                 }
             }
 
             if ("(no subject)".equals(simplifiedSubject)) {
                 simplifiedSubject = "";
             }
 
             int end = len;
 
             while (end > start && subject.charAt(end - 1) < ' ') {
                 end--;
             }
 
             if (start == 0 && end == len) {
                 simplifiedSubject = subject;
             } else {
                 simplifiedSubject = subject.substring(start, end);
             }
         }
     }
 
     @Override
     public boolean subjectIsReply() {
         return isReply;
     }
 
     @Override
     public String toString() { // Useful for Eclipse debugging
         return articleNumber + " " + articleId + " " + subject;
     }
 
 }