package de.spiritscorp.datasync.model;
   
   /*-
    * 		Data Sync
    *
    * 		Copyright ©   2022    The Spirit
    * 		@email                        thespirit@spiritscorp.network
    *
    * 		This program is free software; you can redistribute it and/or modify
   * 		it under the terms of the GNU General Public License as published by
   * 		the Free Software Foundation; either version 3 of the License, or
   * 		(at your option) any later version.
   *
   * 		This program is distributed in the hope that it will be useful,
   * 		but WITHOUT ANY WARRANTY; without even the implied warranty of
   * 		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   * 		See the GNU General Public License for more details.
   *
   * 		You should have received a copy of the GNU General Public License
   * 		along with this program. If not, see <http://www.gnu.org/licenses/>.
   */
  
  import java.nio.file.Path;
  import java.nio.file.attribute.FileTime;
  import java.util.Objects;
  
  /**
   * Immutable value object representing the metadata and diagnostic attributes of a file
   * managed within the synchronization engine context.
   * <p>
   * This class stores timestamps, cryptographic checksums, sizes, and path configurations
   * required to compute delta states between replication nodes.
   * <p>
   *
   * @author Tom Spirit
   * @version 2.0.0
   */
  public final class FileAttributes implements Comparable<FileAttributes> {
  
  	private final Path relativeFilePath;
  	private final String fileName;
  	private final String createTimeString;
  	private final String modTimeString;
  	private final long size;
  	private final String fileHash;
  	private final FileTime createTime;
  	private final FileTime modTime;
  
  	/**
  	 * Constructs a comprehensive metadata record for a single tracked file.
  	 *
  	 * @param relativeFilePath the target file path relative to the source or destination root directory
  	 * @param createTimeString a string representation of the file creation timestamp
  	 * @param createTime       the raw {@link FileTime} of when the file was created
  	 * @param modTimeString    a string representation of the last modification timestamp
  	 * @param modTime          the raw {@link FileTime} of the last modification event
  	 * @param size             the size of the file in bytes
  	 * @param fileHash         the cryptographic checksum signature (SHA-256 or higher)
  	 * @throws NullPointerException if {@code relativeFilePath} is null
  	 */
  	public FileAttributes( Path relativeFilePath, String createTimeString, FileTime createTime, String modTimeString, FileTime modTime, long size, String fileHash ) {
  
  		// Guard against null paths entering the tracking context
  		this.relativeFilePath = Objects.requireNonNull( relativeFilePath, "Relative file path context cannot be null" );
  		// Safely extract the file name string context even for root path definitions
  		final Path namePath = relativeFilePath.getFileName();
  		this.fileName = ( namePath != null ) ? namePath.toString() : relativeFilePath.toString();
  
  		this.createTime = ( createTime != null ) ? FileTime.fromMillis( createTime.toMillis() ) : FileTime.fromMillis( 0 );
  		this.modTime = ( modTime != null ) ? FileTime.fromMillis( modTime.toMillis() ) : FileTime.fromMillis( 0 );
  		this.createTimeString = createTimeString;
  		this.modTimeString = modTimeString;
  		this.size = size;
  		this.fileHash = fileHash;
  	}
  
  	/**
  	 * Compares this file attribute record with another based primarily on file size metrics.
  	 *
  	 * @param o the other {@code FileAttributes} object to compare against
  	 * @return a negative integer, zero, or a positive integer as this file size
  	 *         is less than, equal to, or greater than the specified object's size
  	 */
  	@Override
  	public int compareTo( FileAttributes o ) {
  		return Long.compare( this.size, o.getSize() );
  	}
  
  	@Override
  	public int hashCode() {
  		final int prime = 31;
  		int result = 1;
  		result = prime * result + ( ( createTimeString == null ) ? 0 : createTimeString.hashCode() );
  		result = prime * result + ( ( fileName == null ) ? 0 : fileName.hashCode() );
  		result = prime * result + ( ( relativeFilePath == null ) ? 0 : relativeFilePath.hashCode() );
  		result = prime * result + ( ( modTimeString == null ) ? 0 : modTimeString.hashCode() );
  		result = prime * result + (int) ( size ^ ( size >>> 32 ) );
  		return result;
  	}
 
 	@Override
 	public boolean equals( Object obj ) {
 		if( this == obj )
 			return true;
 		if( obj == null )
 			return false;
 		if( getClass() != obj.getClass() )
 			return false;
 		final FileAttributes other = (FileAttributes) obj;
 		if( fileHash == null ) {
 			if( other.fileHash != null )
 				return false;
 		}else if( !other.fileHash.equals( fileHash ) )
 			return false;
 		if( fileName == null ) {
 			if( other.fileName != null )
 				return false;
 		}else if( !fileName.equals( other.fileName ) )
 			return false;
 		if( relativeFilePath == null ) {
 			if( other.relativeFilePath != null )
 				return false;
 		}else if( !relativeFilePath.equals( other.relativeFilePath ) )
 			return false;
 		if( modTimeString == null ) {
 			if( other.modTimeString != null )
 				return false;
 		}else if( !modTimeString.equals( other.modTimeString ) )
 			return false;
 		if( size != other.size )
 			return false;
 		return true;
 	}
 
 	@Override
 	public String toString() {
 		return "FileAttributes [fileName=" + fileName + ", relativeFilePath=" + relativeFilePath + ", createTimeString="
 				+ createTimeString + ", modTimeString=" + modTimeString + ", size=" + size + ", fileHash=" + fileHash
 				+ ", createTime=" + createTime + ", modTime=" + modTime + "]";
 	}
 
 	// --- Standard Java-Bean Property Accessors APIs layer ---
 
 	/**
 	 * Retrieves the file path relative to the active deployment endpoint layer root.
 	 *
 	 * @return the relative {@link Path}
 	 */
 	public Path getRelativeFilePath() { return relativeFilePath; }
 
 	/**
 	 * Retrieves the human-readable string mapping of the modification timeline entry.
 	 *
 	 * @return the modification timestamp string literal
 	 */
 	public String getModTimeString() { return modTimeString; }
 
 	/**
 	 * Retrieves the native hardware accurate last modified metric vector.
 	 *
 	 * @return the high-precision modification {@link FileTime}
 	 */
 	public FileTime getModTime() { return FileTime.fromMillis( modTime.toMillis() ); }
 
 	/**
 	 * Retrieves the human-readable string mapping of the original creation timeline entry.
 	 *
 	 * @return the creation timestamp string literal
 	 */
 	public String getCreateTimeString() { return createTimeString; }
 
 	/**
 	 * Retrieves the data payload capacity volume layer quantified in bytes.
 	 *
 	 * @return the length of the file as a primitive long value
 	 */
 	public long getSize() { return size; }
 
 	/**
 	 * Retrieves the unique data signature cryptographic validation token checksum.
 	 *
 	 * @return the string-formatted hexadecimal file hash
 	 */
 	public String getFileHash() { return fileHash; }
 
 	/**
 	 * Retrieves the structural file name node excluding directory routing segments.
 	 *
 	 * @return the localized file name string representation
 	 */
 	public String getFileName() { return fileName; }
 
 	/**
 	 * Retrieves the native hardware accurate original initialization filesystem creation marker.
 	 *
 	 * @return the high-precision creation {@link FileTime}
 	 */
 	public FileTime getCreateTime() { return FileTime.fromMillis( createTime.toMillis() ); }
 }