/****************************************************************
    * 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   *
    *                                                              *
   *   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.                                           *
   ****************************************************************/
  
  
  
  package org.apache.james.nntpserver.repository;
  
  import org.apache.james.core.MailHeaders;
  import org.apache.james.nntpserver.NNTPException;
  import org.apache.james.util.io.IOUtil;
  
  import javax.mail.internet.InternetHeaders;
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileReader;
  import java.io.IOException;
  import java.io.OutputStream;
  
  /** 
   * Please see NNTPArticle for comments
   */
  class NNTPArticleImpl implements NNTPArticle {
  
      /**
       * The file that stores the article data
       */
      private final File articleFile;
  
      /**
       * The newsgroup containing this article.
       */
      private final NNTPGroup group;
  
      /**
       * The sole constructor for this class.
       *
       * @param group the news group containing this article
       * @param f the file that stores the article data
       */
      NNTPArticleImpl(NNTPGroup group, File f) {
          articleFile = f;
          this.group = group;
      }
  
      /**
       * @see org.apache.james.nntpserver.repository.NNTPArticle#getGroup()
       */
      public NNTPGroup getGroup() {
          return group;
      }
  
      /**
       * @see org.apache.james.nntpserver.repository.NNTPArticle#getArticleNumber()
       */
      public int getArticleNumber() {
          return Integer.parseInt(articleFile.getName());
      }
  
      /**
       * @see org.apache.james.nntpserver.repository.NNTPArticle#getUniqueID()
       */
      public String getUniqueID() {
          FileInputStream fin = null;
          try {
              fin = new FileInputStream(articleFile);
              InternetHeaders headers = new InternetHeaders(fin);
              String[] idheader = headers.getHeader("Message-Id");
              fin.close();
              return ( idheader.length > 0 ) ? idheader[0] : null;
          } catch(Exception ex) {
              throw new NNTPException(ex);
          } finally {
              IOUtil.shutdownStream(fin);
          }
      }
  
      /**
       * @see org.apache.james.nntpserver.repository.NNTPArticle#writeArticle(OutputStream)
       */
      public void writeArticle(OutputStream out) {
          FileInputStream fileStream = null;
          try {
             fileStream = new FileInputStream(articleFile);
             byte[] readBuffer = new byte[1024];
             int read = 0;
             while ((read = fileStream.read(readBuffer)) > 0) {
                 out.write(readBuffer, 0, read);
             }
         } catch(IOException ex) { 
             throw new NNTPException(ex);
         } finally {
             if (fileStream != null) {
                 try {
                     fileStream.close();
                 } catch (IOException ioe) {
                     // Ignored
                 }
             }
         }
     }
 
     /**
      * @see org.apache.james.nntpserver.repository.NNTPArticle#writeHead(OutputStream)
      */
     public void writeHead(OutputStream out) {
         FileInputStream fileStream = null;
         try {
             fileStream = new FileInputStream(articleFile);
             MailHeaders headers = new MailHeaders(fileStream);
             byte[] headerBuffer = headers.toByteArray();
             int headerBufferLength = headerBuffer.length;
             // Write the headers excluding the final CRLF pair
             if (headerBufferLength > 2) {
                 out.write(headerBuffer, 0, (headerBufferLength - 2));
             }
         } catch(Exception ex) { 
             throw new NNTPException(ex);
         } finally {
             if (fileStream != null) {
                 try {
                     fileStream.close();
                 } catch (IOException ioe) {
                     // Ignored
                 }
             }
         }
     }
 
     /**
      * @see org.apache.james.nntpserver.repository.NNTPArticle#writeBody(OutputStream)
      */
     public void writeBody(OutputStream out) {
         FileInputStream fileStream = null;
         try {
             fileStream = new FileInputStream(articleFile);
             MailHeaders headers = new MailHeaders(fileStream);
             byte[] readBuffer = new byte[1024];
             int read = 0;
             while ((read = fileStream.read(readBuffer)) > 0) {
                 out.write(readBuffer, 0, read);
             }
         } catch(Exception ex) {
             throw new NNTPException(ex);
         } finally {
             if (fileStream != null) {
                 try {
                     fileStream.close();
                 } catch (IOException ioe) {
                     // Ignored
                 }
             }
         }
     }
 
     /**
      * @see org.apache.james.nntpserver.repository.NNTPArticle#writeOverview(OutputStream)
      */
     public void writeOverview(OutputStream out) {
         FileInputStream fileStream = null;
         try {
             fileStream = new FileInputStream(articleFile);
             InternetHeaders hdr = new InternetHeaders(fileStream);
             String subject = hdr.getHeader("Subject",null);
             String author = hdr.getHeader("From",null);
             String date = hdr.getHeader("Date",null);
             String msgId = hdr.getHeader("Message-Id",null);
             String references = hdr.getHeader("References",null);
             long byteCount = articleFile.length();
 
             // get line count, if not set, count the lines
             String lineCount = hdr.getHeader("Lines",null);
             if (lineCount == null) {
                 BufferedReader rdr = new BufferedReader(new FileReader(fileStream.getFD()));
                 int lines = 0;
                 while (rdr.readLine() != null) {
                     lines++;
                 }
 
                 lineCount = Integer.toString(lines);
                 rdr.close();
             }
 
             StringBuffer line=new StringBuffer(256)
                 .append(getArticleNumber())    .append("\t")
                 .append(cleanHeader(subject))    .append("\t")
                 .append(cleanHeader(author))     .append("\t")
                 .append(cleanHeader(date))       .append("\t")
                 .append(cleanHeader(msgId))      .append("\t")
                 .append(cleanHeader(references)) .append("\t")
                 .append(byteCount)               .append("\t")
                 .append(lineCount).append("\r\n");
             String lineString = line.toString();
             out.write(lineString.getBytes("ASCII"));
         } catch(Exception ex) {
             throw new NNTPException(ex);
         } finally {
             if (fileStream != null) {
                 try {
                     fileStream.close();
                 } catch (IOException ioe) {
                     // Ignored
                 }
             }
         }
     }
 
     /**
      * @see org.apache.james.nntpserver.repository.NNTPArticle#getHeader(String)
      */
     public String getHeader(String header) {
         try {
             FileInputStream fin = new FileInputStream(articleFile);
             InternetHeaders hdr = new InternetHeaders(fin);
             fin.close();
             return hdr.getHeader(header,null);
         } catch(Exception ex) {
             throw new NNTPException(ex);
         }
     }
 
     /**
      * Strips out newlines and tabs, converting them to spaces.
      * rfc2980: 2.8 XOVER requires newline and tab to be converted to spaces
      *
      * @param field the input String
      *
      * @return the cleaned string
      */
     private String cleanHeader(String field) {
         if ( field == null )
             field = "";
         StringBuffer sb = new StringBuffer(field);
         for( int i=0 ; i<sb.length() ; i++ ) {
             char c = sb.charAt(i);
             if( (c=='\n') || (c=='\t') || (c=='\r')) {
                 sb.setCharAt(i, ' ');
             }
         }
         return sb.toString();
     }
 }