content: package io.github.tapcard.emvnfccard.iso7816emv.impl;
  
  /*
   * Copyright 2010 sasc
   *
   * 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.
   */
  
  import java.util.Arrays;
  
  import io.github.tapcard.emvnfccard.enums.TagTypeEnum;
  import io.github.tapcard.emvnfccard.enums.TagValueTypeEnum;
  import io.github.tapcard.emvnfccard.iso7816emv.ITag;
  
  import io.github.tapcard.emvnfccard.utils.BytesUtils;
  
  /**
   * 
   * @author sasc
   */
  public final class TagImpl implements ITag {
  
  	private final byte[] idBytes;
  	public final String name;
  	private final String description;
  	private final TagValueTypeEnum tagValueType;
  	private final Class tagClass;
  	private final TagTypeEnum type;
  
  	public TagImpl(final String id, final TagValueTypeEnum tagValueType, final String name, final String description) {
  		this(BytesUtils.fromString(id), tagValueType, name, description);
  	}
  
  	public TagImpl(final byte[] idBytes, final TagValueTypeEnum tagValueType, final String name, final String description) {
  		if (idBytes == null) {
  			throw new IllegalArgumentException("Param id cannot be null");
  		}
  		if (idBytes.length == 0) {
  			throw new IllegalArgumentException("Param id cannot be empty");
  		}
  		if (tagValueType == null) {
  			throw new IllegalArgumentException("Param tagValueType cannot be null");
  		}
  		this.idBytes = idBytes;
  		this.name = name;
  		this.description = description;
  		this.tagValueType = tagValueType;
  
  		if (BytesUtils.matchBitByBitIndex(this.idBytes[0], 5)) {
  			type = TagTypeEnum.CONSTRUCTED;
  		} else {
  			type = TagTypeEnum.PRIMITIVE;
  		}
  		// Bits 8 and 7 of the first byte of the tag field indicate a class.
  		// The value 00 indicates a data object of the universal class.
  		// The value 01 indicates a data object of the application class.
  		// The value 10 indicates a data object of the context-specific class.
  		// The value 11 indicates a data object of the private class.
  		byte classValue = (byte) (this.idBytes[0] >>> 6 & 0x03);
  		switch (classValue) {
  		case (byte) 0x01:
  			tagClass = Class.APPLICATION;
  			break;
  		case (byte) 0x02:
  			tagClass = Class.CONTEXT_SPECIFIC;
  			break;
  		case (byte) 0x03:
  			tagClass = Class.PRIVATE;
  			break;
  		default:
  			tagClass = Class.UNIVERSAL;
  			break;
  		}
  
  	}
  
  	@Override
  	public boolean isConstructed() {
  		return type == TagTypeEnum.CONSTRUCTED;
  	}
  
  	@Override
  	public byte[] getTagBytes() {
  		return idBytes;
  	}
  
  	@Override
  	public String getName() {
  		return name;
  	}
  
  	@Override
  	public String getDescription() {
  		return description;
  	}
  
  	@Override
  	public TagValueTypeEnum getTagValueType() {
  		return tagValueType;
  	}
  
  	@Override
  	public TagTypeEnum getType() {
  		return type;
  	}
  
  	@Override
  	public Class getTagClass() {
  		return tagClass;
  	}
  
  	@Override
  	public boolean equals(final Object other) {
  		if (!(other instanceof ITag)) {
  			return false;
  		}
  		ITag that = (ITag) other;
  		if (getTagBytes().length != that.getTagBytes().length) {
  			return false;
  		}
  
  		return Arrays.equals(getTagBytes(), that.getTagBytes());
  	}
  
  	@Override
  	public int hashCode() {
  		int hash = 3;
  		hash = 59 * hash + Arrays.hashCode(idBytes);
  		return hash;
  	}
  
  	@Override
  	public int getNumTagBytes() {
  		return idBytes.length;
  	}
  
  	@Override
  	public String toString() {
  		StringBuilder sb = new StringBuilder();
  		sb.append("Tag[");
  		sb.append(BytesUtils.bytesToString(getTagBytes()));
  		sb.append("] Name=");
  		sb.append(getName());
  		sb.append(", TagType=");
  		sb.append(getType());
  		sb.append(", ValueType=");
  		sb.append(getTagValueType());
  		sb.append(", Class=");
  		sb.append(tagClass);
  		return sb.toString();
  	}
  }
  