/*
    * 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.hadoop.hbase.security.access;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.util.Bytes;
  
  import java.io.DataInput;
  import java.io.DataOutput;
  import java.io.IOException;
  
  /**
   * Represents an authorization for access for the given actions, optionally
   * restricted to the given column family or column qualifier, over the
   * given table.  If the family property is <code>null</code>, it implies
   * full table access.
   */
  @InterfaceAudience.Private
  public class TablePermission extends Permission {
    private static final Log LOG = LogFactory.getLog(TablePermission.class);
  
    private TableName table;
    private byte[] family;
    private byte[] qualifier;
  
    //TODO refactor this class
    //we need to refacting this into three classes (Global, Table, Namespace)
    private String namespace;
  
    /** Nullary constructor for Writable, do not use */
    public TablePermission() {
      super();
    }
  
    /**
     * Create a new permission for the given table and (optionally) column family,
     * allowing the given actions.
     * @param table the table
     * @param family the family, can be null if a global permission on the table
     * @param assigned the list of allowed actions
     */
    public TablePermission(TableName table, byte[] family, Action... assigned) {
      this(table, family, null, assigned);
    }
  
    /**
     * Creates a new permission for the given table, restricted to the given
     * column family and qualifier, allowing the assigned actions to be performed.
     * @param table the table
     * @param family the family, can be null if a global permission on the table
     * @param assigned the list of allowed actions
     */
    public TablePermission(TableName table, byte[] family, byte[] qualifier,
        Action... assigned) {
      super(assigned);
      this.table = table;
      this.family = family;
      this.qualifier = qualifier;
    }
  
    /**
     * Creates a new permission for the given table, family and column qualifier,
     * allowing the actions matching the provided byte codes to be performed.
     * @param table the table
     * @param family the family, can be null if a global permission on the table
     * @param actionCodes the list of allowed action codes
     */
    public TablePermission(TableName table, byte[] family, byte[] qualifier,
        byte[] actionCodes) {
      super(actionCodes);
      this.table = table;
      this.family = family;
      this.qualifier = qualifier;
    }
  
    /**
     * Creates a new permission for the given namespace or table, restricted to the given
     * column family and qualifier, allowing the assigned actions to be performed.
     * @param namespace
    * @param table the table
    * @param family the family, can be null if a global permission on the table
    * @param assigned the list of allowed actions
    */
   public TablePermission(String namespace, TableName table, byte[] family, byte[] qualifier,
       Action... assigned) {
     super(assigned);
     this.namespace = namespace;
     this.table = table;
     this.family = family;
     this.qualifier = qualifier;
   }
 
   /**
    * Creates a new permission for the given namespace or table, family and column qualifier,
    * allowing the actions matching the provided byte codes to be performed.
    * @param namespace
    * @param table the table
    * @param family the family, can be null if a global permission on the table
    * @param actionCodes the list of allowed action codes
    */
   public TablePermission(String namespace, TableName table, byte[] family, byte[] qualifier,
       byte[] actionCodes) {
     super(actionCodes);
     this.namespace = namespace;
     this.table = table;
     this.family = family;
     this.qualifier = qualifier;
   }
 
   /**
    * Creates a new permission for the given namespace,
    * allowing the actions matching the provided byte codes to be performed.
    * @param namespace
    * @param actionCodes the list of allowed action codes
    */
   public TablePermission(String namespace, byte[] actionCodes) {
     super(actionCodes);
     this.namespace = namespace;
   }
 
   /**
    * Create a new permission for the given namespace,
    * allowing the given actions.
    * @param namespace
    * @param assigned the list of allowed actions
    */
   public TablePermission(String namespace, Action... assigned) {
     super(assigned);
     this.namespace = namespace;
   }
 
   public boolean hasTable() {
     return table != null;
   }
 
   public TableName getTableName() {
     return table;
   }
 
   public boolean hasFamily() {
     return family != null;
   }
 
   public byte[] getFamily() {
     return family;
   }
 
   public boolean hasQualifier() {
     return qualifier != null;
   }
 
   public byte[] getQualifier() {
     return qualifier;
   }
 
   public boolean hasNamespace() {
     return namespace != null;
   }
 
   public String getNamespace() {
     return namespace;
   }
 
   /**
    * Checks that a given table operation is authorized by this permission
    * instance.
    *
    * @param namespace the namespace where the operation is being performed
    * @param action the action being requested
    * @return <code>true</code> if the action within the given scope is allowed
    *   by this permission, <code>false</code>
    */
   public boolean implies(String namespace, Action action) {
     if (!this.namespace.equals(namespace)) {
       return false;
     }
 
     // check actions
     return super.implies(action);
   }
 
   /**
    * Checks that a given table operation is authorized by this permission
    * instance.
    *
    * @param table the table where the operation is being performed
    * @param family the column family to which the operation is restricted,
    *   if <code>null</code> implies "all"
    * @param qualifier the column qualifier to which the action is restricted,
    *   if <code>null</code> implies "all"
    * @param action the action being requested
    * @return <code>true</code> if the action within the given scope is allowed
    *   by this permission, <code>false</code>
    */
   public boolean implies(TableName table, byte[] family, byte[] qualifier,
       Action action) {
     if (!this.table.equals(table)) {
       return false;
     }
 
     if (this.family != null &&
         (family == null ||
          !Bytes.equals(this.family, family))) {
       return false;
     }
 
     if (this.qualifier != null &&
         (qualifier == null ||
          !Bytes.equals(this.qualifier, qualifier))) {
       return false;
     }
 
     // check actions
     return super.implies(action);
   }
 
   /**
    * Checks if this permission grants access to perform the given action on
    * the given table and key value.
    * @param table the table on which the operation is being performed
    * @param kv the KeyValue on which the operation is being requested
    * @param action the action requested
    * @return <code>true</code> if the action is allowed over the given scope
    *   by this permission, otherwise <code>false</code>
    */
   public boolean implies(TableName table, KeyValue kv, Action action) {
     if (!this.table.equals(table)) {
       return false;
     }
 
     if (family != null &&
         (Bytes.compareTo(family, 0, family.length,
             kv.getFamilyArray(), kv.getFamilyOffset(), kv.getFamilyLength()) != 0)) {
       return false;
     }
 
     if (qualifier != null &&
         (Bytes.compareTo(qualifier, 0, qualifier.length,
             kv.getQualifierArray(), kv.getQualifierOffset(), kv.getQualifierLength()) != 0)) {
       return false;
     }
 
     // check actions
     return super.implies(action);
   }
 
   /**
    * Returns <code>true</code> if this permission matches the given column
    * family at least.  This only indicates a partial match against the table
    * and column family, however, and does not guarantee that implies() for the
    * column same family would return <code>true</code>.  In the case of a
    * column-qualifier specific permission, for example, implies() would still
    * return false.
    */
   public boolean matchesFamily(TableName table, byte[] family, Action action) {
     if (!this.table.equals(table)) {
       return false;
     }
 
     if (this.family != null &&
         (family == null ||
          !Bytes.equals(this.family, family))) {
       return false;
     }
 
     // ignore qualifier
     // check actions
     return super.implies(action);
   }
 
   /**
    * Returns if the given permission matches the given qualifier.
    * @param table the table name to match
    * @param family the column family to match
    * @param qualifier the qualifier name to match
    * @param action the action requested
    * @return <code>true</code> if the table, family and qualifier match,
    *   otherwise <code>false</code>
    */
   public boolean matchesFamilyQualifier(TableName table, byte[] family, byte[] qualifier,
                                 Action action) {
     if (!matchesFamily(table, family, action)) {
       return false;
     } else {
       if (this.qualifier != null &&
           (qualifier == null ||
            !Bytes.equals(this.qualifier, qualifier))) {
         return false;
       }
     }
     return super.implies(action);
   }
 
   @Override
   @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="NP_NULL_ON_SOME_PATH",
     justification="Passed on construction except on constructor not to be used")
   public boolean equals(Object obj) {
     if (!(obj instanceof TablePermission)) {
       return false;
     }
     TablePermission other = (TablePermission)obj;
 
     if (!(table.equals(other.getTableName()) &&
         ((family == null && other.getFamily() == null) ||
          Bytes.equals(family, other.getFamily())) &&
         ((qualifier == null && other.getQualifier() == null) ||
          Bytes.equals(qualifier, other.getQualifier())) &&
         ((namespace == null && other.getNamespace() == null) ||
          (namespace != null && namespace.equals(other.getNamespace())))
        )) {
       return false;
     }
 
     // check actions
     return super.equals(other);
   }
 
   @Override
   public int hashCode() {
     final int prime = 37;
     int result = super.hashCode();
     if (table != null) {
       result = prime * result + table.hashCode();
     }
     if (family != null) {
       result = prime * result + Bytes.hashCode(family);
     }
     if (qualifier != null) {
       result = prime * result + Bytes.hashCode(qualifier);
     }
     if (namespace != null) {
       result = prime * result + namespace.hashCode();
     }
     return result;
   }
 
   @Override
   public String toString() {
     StringBuilder str = new StringBuilder("[TablePermission: ");
     if(namespace != null) {
       str.append("namespace=").append(namespace)
          .append(", ");
     }
     else if(table != null) {
        str.append("table=").append(table)
           .append(", family=")
           .append(family == null ? null : Bytes.toString(family))
           .append(", qualifier=")
           .append(qualifier == null ? null : Bytes.toString(qualifier))
           .append(", ");
     } else {
       str.append("actions=");
     }
     if (actions != null) {
       for (int i=0; i<actions.length; i++) {
         if (i > 0)
           str.append(",");
         if (actions[i] != null)
           str.append(actions[i].toString());
         else
           str.append("NULL");
       }
     }
     str.append("]");
 
     return str.toString();
   }
 
   @Override
   public void readFields(DataInput in) throws IOException {
     super.readFields(in);
     byte[] tableBytes = Bytes.readByteArray(in);
     table = TableName.valueOf(tableBytes);
     if (in.readBoolean()) {
       family = Bytes.readByteArray(in);
     }
     if (in.readBoolean()) {
       qualifier = Bytes.readByteArray(in);
     }
     if(in.readBoolean()) {
       namespace = Bytes.toString(Bytes.readByteArray(in));
     }
   }
 
   @Override
   public void write(DataOutput out) throws IOException {
     super.write(out);
     Bytes.writeByteArray(out, table.getName());
     out.writeBoolean(family != null);
     if (family != null) {
       Bytes.writeByteArray(out, family);
     }
     out.writeBoolean(qualifier != null);
     if (qualifier != null) {
       Bytes.writeByteArray(out, qualifier);
     }
     out.writeBoolean(namespace != null);
     if(namespace != null) {
       Bytes.writeByteArray(out, Bytes.toBytes(namespace));
     }
   }
 }