/**
 * 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.sentry.provider.db.service.model;

import java.util.HashSet;
import java.util.Set;

import javax.jdo.annotations.PersistenceCapable;

import org.apache.sentry.core.common.utils.PathUtils;
import org.apache.sentry.core.common.utils.SentryUtils;
import org.apache.sentry.core.model.db.AccessConstants;
import org.apache.sentry.provider.db.service.persistent.SentryStore;
import org.apache.sentry.provider.db.service.persistent.PrivilegePrincipal;
import org.apache.sentry.service.common.ServiceConstants.SentryPrincipalType;

/**
 * Database backed Sentry Privilege. Any changes to this object
 * require re-running the maven build so DN an re-enhance.
 */
@PersistenceCapable
public class MSentryPrivilege {

  private String privilegeScope;
  /**
   * Privilege name is unique
   */
  private String serverName = "";
  private String dbName = "";
  private String tableName = "";
  private String columnName = "";
  private String URI = "";
  private String action = "";
  private Boolean grantOption = false;
  // roles this privilege is a part of
  private Set<MSentryRole> roles;
  // users this privilege is a part of
  private Set<MSentryUser> users;
  private long createTime;

  public MSentryPrivilege() {
    this.roles = new HashSet<>();
    this.users = new HashSet<>();
  }

  public MSentryPrivilege(String privilegeScope,
      String serverName, String dbName, String tableName, String columnName,
      String URI, String action, Boolean grantOption) {
    this.privilegeScope = MSentryUtil.safeIntern(privilegeScope);
    this.serverName = MSentryUtil.safeIntern(serverName);
    this.dbName = SentryStore.toNULLCol(dbName).intern();
    this.tableName = SentryStore.toNULLCol(tableName).intern();
    this.columnName = SentryStore.toNULLCol(columnName).intern();
    this.URI = SentryStore.toNULLCol(URI).intern();
    this.action = SentryStore.toNULLCol(action).intern();
    this.grantOption = grantOption;
    this.roles = new HashSet<>();
    this.users = new HashSet<>();
  }

  public MSentryPrivilege(String privilegeScope,
      String serverName, String dbName, String tableName, String columnName,
      String URI, String action) {
    this(privilegeScope, serverName, dbName, tableName,
        columnName, URI, action, false);
  }

  public MSentryPrivilege(MSentryPrivilege other) {
    this.privilegeScope = other.privilegeScope;
    this.serverName = other.serverName;
    this.dbName = SentryStore.toNULLCol(other.dbName).intern();
    this.tableName = SentryStore.toNULLCol(other.tableName).intern();
    this.columnName = SentryStore.toNULLCol(other.columnName).intern();
    this.URI = SentryStore.toNULLCol(other.URI).intern();
    this.action = SentryStore.toNULLCol(other.action).intern();
    this.grantOption = other.grantOption;
    this.roles = new HashSet<>();
    roles.addAll(other.roles);
    this.users = new HashSet<>();
    users.addAll(other.users);
  }

  public String getServerName() {
    return serverName;
  }

  public void setServerName(String serverName) {
    this.serverName = (serverName == null) ? "" : serverName;
  }

  public String getDbName() {
    return dbName;
  }

  public void setDbName(String dbName) {
    this.dbName = (dbName == null) ? "" : dbName;
  }

  public String getTableName() {
    return tableName;
  }

  public void setTableName(String tableName) {
    this.tableName = (tableName == null) ? "" : tableName;
  }

  public String getColumnName() {
    return columnName;
  }

  public void setColumnName(String columnName) {
    this.columnName = (columnName == null) ? "" : columnName;
  }

  public String getURI() {
    return URI;
  }

  public void setURI(String uRI) {
    URI = (uRI == null) ? "" : uRI;
  }

  public String getAction() {
    return action;
  }

  public void setAction(String action) {
    this.action = (action == null) ? "" : action;
  }

  public long getCreateTime() {
    return createTime;
  }

  public void setCreateTime(long createTime) {
    this.createTime = createTime;
  }

  public String getPrivilegeScope() {
    return privilegeScope;
  }

  public void setPrivilegeScope(String privilegeScope) {
    this.privilegeScope = privilegeScope;
  }

   public Boolean getGrantOption() {
     return grantOption;
   }

   public void setGrantOption(Boolean grantOption) {
     this.grantOption = grantOption;
   }

  /**
   * Appends Role/User in the privilege.
   * @param principal Role/User to be appended.
   */
  public void appendPrincipal(PrivilegePrincipal principal) {
    if(principal.getPrincipalType() == SentryPrincipalType.ROLE) {
      roles.add((MSentryRole)principal);
    } else  if(principal.getPrincipalType() == SentryPrincipalType.USER) {
      users.add((MSentryUser)principal);
    }
  }

  public Set<MSentryRole> getRoles() {
    return roles;
  }

  public Set<MSentryUser> getUsers() { return users; }

  /**
   * Removes Role/User in the privilege.
   * @param principal Role/User to be removed.
   */
  public void removePrincipal(PrivilegePrincipal principal) {
    if(principal.getPrincipalType() == SentryPrincipalType.ROLE && (roles != null) && (roles.size() > 0)) {
      roles.remove((MSentryRole)principal);
    } else  if(principal.getPrincipalType() == SentryPrincipalType.USER && (users != null) && (users.size() > 0)) {
      users.remove((MSentryUser)principal);
    }
    principal.removePrivilege(this);
  }

  public void removeUser(MSentryUser user) {
    users.remove(user);
    user.removePrivilege(this);
  }

  @Override
  public String toString() {
    return "MSentryPrivilege [privilegeScope=" + privilegeScope
        + ", serverName=" + serverName + ", dbName=" + dbName
        + ", tableName=" + tableName + ", columnName=" + columnName
        + ", URI=" + URI + ", action=" + action + ", roles=[...]" + ", users=[...]"
        + ", createTime=" + createTime + ", grantOption=" + grantOption +"]";
  }

  @Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((URI == null) ? 0 : URI.hashCode());
    result = prime * result + ((action == null) ? 0 : action.hashCode());
    result = prime * result + ((dbName == null) ? 0 : dbName.hashCode());
    result = prime * result
        + ((serverName == null) ? 0 : serverName.hashCode());
    result = prime * result + ((tableName == null) ? 0 : tableName.hashCode());
    result = prime * result
        + ((columnName == null) ? 0 : columnName.hashCode());
    result = prime * result
        + ((grantOption == null) ? 0 : grantOption.hashCode());
    return result;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    MSentryPrivilege other = (MSentryPrivilege) obj;
    if (URI == null) {
      if (other.URI != null) {
        return false;
      }
    } else if (!URI.equals(other.URI)) {
      return false;
    }
    if (action == null) {
      if (other.action != null) {
        return false;
      }
    } else if (!action.equals(other.action)) {
      return false;
    }
    if (dbName == null) {
      if (other.dbName != null) {
        return false;
      }
    } else if (!dbName.equals(other.dbName)) {
      return false;
    }
    if (serverName == null) {
      if (other.serverName != null) {
        return false;
      }
    } else if (!serverName.equals(other.serverName)) {
      return false;
    }
    if (tableName == null) {
      if (other.tableName != null) {
        return false;
      }
    } else if (!tableName.equals(other.tableName)) {
      return false;
    }
    if (columnName == null) {
      if (other.columnName != null) {
        return false;
      }
    } else if (!columnName.equals(other.columnName)) {
      return false;
    }
    if (grantOption == null) {
      if (other.grantOption != null) {
        return false;
      }
    } else if (!grantOption.equals(other.grantOption)) {
      return false;
    }
    return true;
  }

  /**
   * Return true if this privilege implies other privilege
   * Otherwise, return false
   * @param other, other privilege
   */
  public boolean implies(MSentryPrivilege other) {
    // serverName never be null
    if (isNULL(serverName) || isNULL(other.serverName)) {
      return false;
    } else if (!serverName.equals(other.serverName)) {
      return false;
    }

    // check URI implies
    if (!isNULL(URI) && !isNULL(other.URI)) {
      if (!PathUtils.impliesURI(URI, other.URI)) {
        return false;
      }
      // if URI is NULL, check dbName and tableName
    } else if (isNULL(URI) && isNULL(other.URI)) {
      if (!isNULL(dbName)) {
        if (isNULL(other.dbName)) {
          return false;
        } else if (!dbName.equals(other.dbName)) {
          return false;
        }
      }
      if (!isNULL(tableName)) {
        if (isNULL(other.tableName)) {
          return false;
        } else if (!tableName.equals(other.tableName)) {
          return false;
        }
      }
      if (!isNULL(columnName)) {
        if (isNULL(other.columnName)) {
          return false;
        } else if (!columnName.equals(other.columnName)) {
          return false;
        }
      }
      // if URI is not NULL, but other's URI is NULL, return false
    } else if (!isNULL(URI) && isNULL(other.URI)){
      return false;
    }

    // check action implies
    if (!action.equalsIgnoreCase(AccessConstants.ALL)
        && !action.equalsIgnoreCase(AccessConstants.OWNER)
        && !action.equalsIgnoreCase(other.action)
        && !action.equalsIgnoreCase(AccessConstants.ACTION_ALL)) {
      return false;
    }

    return true;
  }

  private boolean isNULL(String s) {
    return SentryUtils.isNULL(s);
  }

  public boolean isActionALL() {
    return AccessConstants.ACTION_ALL.equalsIgnoreCase(action)
        || AccessConstants.ALL.equals(action);
  }

}