/**
    * 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.master.procedure;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.security.PrivilegedExceptionAction;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.MetaTableAccessor;
  import org.apache.hadoop.hbase.TableExistsException;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.TableStateManager;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.client.RegionReplicaUtil;
  import org.apache.hadoop.hbase.exceptions.HBaseException;
  import org.apache.hadoop.hbase.master.AssignmentManager;
  import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
  import org.apache.hadoop.hbase.master.MasterFileSystem;
  import org.apache.hadoop.hbase.procedure2.StateMachineProcedure;
  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProcedureProtos;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProcedureProtos.CreateTableState;
  import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos;
  import org.apache.hadoop.hbase.util.FSTableDescriptors;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.apache.hadoop.hbase.util.ModifyRegionUtils;
  import org.apache.hadoop.hbase.util.ServerRegionReplicaUtil;
  import org.apache.hadoop.security.UserGroupInformation;
  
  import com.google.common.collect.Lists;
  
  @InterfaceAudience.Private
  public class CreateTableProcedure
      extends StateMachineProcedure<MasterProcedureEnv, CreateTableState>
      implements TableProcedureInterface {
    private static final Log LOG = LogFactory.getLog(CreateTableProcedure.class);
  
    private final AtomicBoolean aborted = new AtomicBoolean(false);
  
    // used for compatibility with old clients
    private final ProcedurePrepareLatch syncLatch;
  
    private HTableDescriptor hTableDescriptor;
    private List<HRegionInfo> newRegions;
    private UserGroupInformation user;
  
    public CreateTableProcedure() {
      // Required by the Procedure framework to create the procedure on replay
      syncLatch = null;
    }
  
    public CreateTableProcedure(final MasterProcedureEnv env,
        final HTableDescriptor hTableDescriptor, final HRegionInfo[] newRegions) {
      this(env, hTableDescriptor, newRegions, null);
    }
  
    public CreateTableProcedure(final MasterProcedureEnv env,
        final HTableDescriptor hTableDescriptor, final HRegionInfo[] newRegions,
        final ProcedurePrepareLatch syncLatch) {
      this.hTableDescriptor = hTableDescriptor;
      this.newRegions = newRegions != null ? Lists.newArrayList(newRegions) : null;
      this.user = env.getRequestUser().getUGI();
      this.setOwner(this.user.getShortUserName());
  
      // used for compatibility with clients without procedures
      // they need a sync TableExistsException
      this.syncLatch = syncLatch;
    }
  
    @Override
    protected Flow executeFromState(final MasterProcedureEnv env, final CreateTableState state)
        throws InterruptedException {
      if (LOG.isTraceEnabled()) {
       LOG.trace(this + " execute state=" + state);
     }
     try {
       switch (state) {
         case CREATE_TABLE_PRE_OPERATION:
           // Verify if we can create the table
           boolean exists = !prepareCreate(env);
           ProcedurePrepareLatch.releaseLatch(syncLatch, this);
 
           if (exists) {
             assert isFailed() : "the delete should have an exception here";
             return Flow.NO_MORE_STATE;
           }
 
           preCreate(env);
           setNextState(CreateTableState.CREATE_TABLE_WRITE_FS_LAYOUT);
           break;
         case CREATE_TABLE_WRITE_FS_LAYOUT:
           newRegions = createFsLayout(env, hTableDescriptor, newRegions);
           setNextState(CreateTableState.CREATE_TABLE_ADD_TO_META);
           break;
         case CREATE_TABLE_ADD_TO_META:
           newRegions = addTableToMeta(env, hTableDescriptor, newRegions);
           setNextState(CreateTableState.CREATE_TABLE_ASSIGN_REGIONS);
           break;
         case CREATE_TABLE_ASSIGN_REGIONS:
           assignRegions(env, getTableName(), newRegions);
           setNextState(CreateTableState.CREATE_TABLE_UPDATE_DESC_CACHE);
           break;
         case CREATE_TABLE_UPDATE_DESC_CACHE:
           updateTableDescCache(env, getTableName());
           setNextState(CreateTableState.CREATE_TABLE_POST_OPERATION);
           break;
         case CREATE_TABLE_POST_OPERATION:
           postCreate(env);
           return Flow.NO_MORE_STATE;
         default:
           throw new UnsupportedOperationException("unhandled state=" + state);
       }
     } catch (HBaseException|IOException e) {
       LOG.error("Error trying to create table=" + getTableName() + " state=" + state, e);
       setFailure("master-create-table", e);
     }
     return Flow.HAS_MORE_STATE;
   }
 
   @Override
   protected void rollbackState(final MasterProcedureEnv env, final CreateTableState state)
       throws IOException {
     if (LOG.isTraceEnabled()) {
       LOG.trace(this + " rollback state=" + state);
     }
     try {
       switch (state) {
         case CREATE_TABLE_POST_OPERATION:
           break;
         case CREATE_TABLE_UPDATE_DESC_CACHE:
           DeleteTableProcedure.deleteTableDescriptorCache(env, getTableName());
           break;
         case CREATE_TABLE_ASSIGN_REGIONS:
           DeleteTableProcedure.deleteAssignmentState(env, getTableName());
           break;
         case CREATE_TABLE_ADD_TO_META:
           DeleteTableProcedure.deleteFromMeta(env, getTableName(), newRegions);
           break;
         case CREATE_TABLE_WRITE_FS_LAYOUT:
           DeleteTableProcedure.deleteFromFs(env, getTableName(), newRegions, false);
           break;
         case CREATE_TABLE_PRE_OPERATION:
           DeleteTableProcedure.deleteTableStates(env, getTableName());
           // TODO-MAYBE: call the deleteTable coprocessor event?
           ProcedurePrepareLatch.releaseLatch(syncLatch, this);
           break;
         default:
           throw new UnsupportedOperationException("unhandled state=" + state);
       }
     } catch (HBaseException e) {
       LOG.warn("Failed rollback attempt step=" + state + " table=" + getTableName(), e);
       throw new IOException(e);
     } catch (IOException e) {
       // This will be retried. Unless there is a bug in the code,
       // this should be just a "temporary error" (e.g. network down)
       LOG.warn("Failed rollback attempt step=" + state + " table=" + getTableName(), e);
       throw e;
     }
   }
 
   @Override
   protected CreateTableState getState(final int stateId) {
     return CreateTableState.valueOf(stateId);
   }
 
   @Override
   protected int getStateId(final CreateTableState state) {
     return state.getNumber();
   }
 
   @Override
   protected CreateTableState getInitialState() {
     return CreateTableState.CREATE_TABLE_PRE_OPERATION;
   }
 
   @Override
   protected void setNextState(final CreateTableState state) {
     if (aborted.get()) {
       setAbortFailure("create-table", "abort requested");
     } else {
       super.setNextState(state);
     }
   }
 
   @Override
   public TableName getTableName() {
     return hTableDescriptor.getTableName();
   }
 
   @Override
   public TableOperationType getTableOperationType() {
     return TableOperationType.CREATE;
   }
 
   @Override
   public boolean abort(final MasterProcedureEnv env) {
     aborted.set(true);
     return true;
   }
 
   @Override
   public void toStringClassDetails(StringBuilder sb) {
     sb.append(getClass().getSimpleName());
     sb.append(" (table=");
     sb.append(getTableName());
     sb.append(")");
   }
 
   @Override
   public void serializeStateData(final OutputStream stream) throws IOException {
     super.serializeStateData(stream);
 
     MasterProcedureProtos.CreateTableStateData.Builder state =
       MasterProcedureProtos.CreateTableStateData.newBuilder()
         .setUserInfo(MasterProcedureUtil.toProtoUserInfo(this.user))
         .setTableSchema(hTableDescriptor.convert());
     if (newRegions != null) {
       for (HRegionInfo hri: newRegions) {
         state.addRegionInfo(HRegionInfo.convert(hri));
       }
     }
     state.build().writeDelimitedTo(stream);
   }
 
   @Override
   public void deserializeStateData(final InputStream stream) throws IOException {
     super.deserializeStateData(stream);
 
     MasterProcedureProtos.CreateTableStateData state =
       MasterProcedureProtos.CreateTableStateData.parseDelimitedFrom(stream);
     user = MasterProcedureUtil.toUserInfo(state.getUserInfo());
     hTableDescriptor = HTableDescriptor.convert(state.getTableSchema());
     if (state.getRegionInfoCount() == 0) {
       newRegions = null;
     } else {
       newRegions = new ArrayList<HRegionInfo>(state.getRegionInfoCount());
       for (HBaseProtos.RegionInfo hri: state.getRegionInfoList()) {
         newRegions.add(HRegionInfo.convert(hri));
       }
     }
   }
 
   @Override
   protected boolean acquireLock(final MasterProcedureEnv env) {
     if (!getTableName().isSystemTable() && env.waitInitialized(this)) {
       return false;
     }
     return env.getProcedureQueue().tryAcquireTableExclusiveLock(this, getTableName());
   }
 
   @Override
   protected void releaseLock(final MasterProcedureEnv env) {
     env.getProcedureQueue().releaseTableExclusiveLock(this, getTableName());
   }
 
   private boolean prepareCreate(final MasterProcedureEnv env) throws IOException {
     final TableName tableName = getTableName();
     if (MetaTableAccessor.tableExists(env.getMasterServices().getConnection(), tableName)) {
       setFailure("master-create-table", new TableExistsException(getTableName()));
       return false;
     }
     // During master initialization, the ZK state could be inconsistent from failed DDL
     // in the past. If we fail here, it would prevent master to start.  We should force
     // setting the system table state regardless the table state.
     boolean skipTableStateCheck =
         !(env.getMasterServices().isInitialized()) && tableName.isSystemTable();
     if (!skipTableStateCheck) {
       TableStateManager tsm = env.getMasterServices().getAssignmentManager().getTableStateManager();
       if (tsm.isTableState(tableName, true, ZooKeeperProtos.Table.State.ENABLING,
           ZooKeeperProtos.Table.State.ENABLED)) {
         LOG.warn("The table " + tableName + " does not exist in meta but has a znode. " +
                "run hbck to fix inconsistencies.");
         setFailure("master-create-table", new TableExistsException(getTableName()));
         return false;
       }
     }
     return true;
   }
 
   private void preCreate(final MasterProcedureEnv env)
       throws IOException, InterruptedException {
     if (!getTableName().isSystemTable()) {
       ProcedureSyncWait.getMasterQuotaManager(env)
         .checkNamespaceTableAndRegionQuota(getTableName(), newRegions.size());
     }
 
     final MasterCoprocessorHost cpHost = env.getMasterCoprocessorHost();
     if (cpHost != null) {
       final HRegionInfo[] regions = newRegions == null ? null :
         newRegions.toArray(new HRegionInfo[newRegions.size()]);
       user.doAs(new PrivilegedExceptionAction<Void>() {
         @Override
         public Void run() throws Exception {
           cpHost.preCreateTableHandler(hTableDescriptor, regions);
           return null;
         }
       });
     }
   }
 
   private void postCreate(final MasterProcedureEnv env)
       throws IOException, InterruptedException {
     final MasterCoprocessorHost cpHost = env.getMasterCoprocessorHost();
     if (cpHost != null) {
       final HRegionInfo[] regions = (newRegions == null) ? null :
         newRegions.toArray(new HRegionInfo[newRegions.size()]);
       user.doAs(new PrivilegedExceptionAction<Void>() {
         @Override
         public Void run() throws Exception {
           cpHost.postCreateTableHandler(hTableDescriptor, regions);
           return null;
         }
       });
     }
   }
 
   protected interface CreateHdfsRegions {
     List<HRegionInfo> createHdfsRegions(final MasterProcedureEnv env,
       final Path tableRootDir, final TableName tableName,
       final List<HRegionInfo> newRegions) throws IOException;
   }
 
   protected static List<HRegionInfo> createFsLayout(final MasterProcedureEnv env,
       final HTableDescriptor hTableDescriptor, final List<HRegionInfo> newRegions)
       throws IOException {
     return createFsLayout(env, hTableDescriptor, newRegions, new CreateHdfsRegions() {
       @Override
       public List<HRegionInfo> createHdfsRegions(final MasterProcedureEnv env,
           final Path tableRootDir, final TableName tableName,
           final List<HRegionInfo> newRegions) throws IOException {
         HRegionInfo[] regions = newRegions != null ?
           newRegions.toArray(new HRegionInfo[newRegions.size()]) : null;
         return ModifyRegionUtils.createRegions(env.getMasterConfiguration(),
             tableRootDir, hTableDescriptor, regions, null);
       }
     });
   }
 
   protected static List<HRegionInfo> createFsLayout(final MasterProcedureEnv env,
       final HTableDescriptor hTableDescriptor, List<HRegionInfo> newRegions,
       final CreateHdfsRegions hdfsRegionHandler) throws IOException {
     final MasterFileSystem mfs = env.getMasterServices().getMasterFileSystem();
     final Path tempdir = mfs.getTempDir();
 
     // 1. Create Table Descriptor
     // using a copy of descriptor, table will be created enabling first
     final Path tempTableDir = FSUtils.getTableDir(tempdir, hTableDescriptor.getTableName());
     new FSTableDescriptors(env.getMasterConfiguration()).createTableDescriptorForTableDirectory(
       tempTableDir, hTableDescriptor, false);
 
     // 2. Create Regions
     newRegions = hdfsRegionHandler.createHdfsRegions(env, tempdir,
       hTableDescriptor.getTableName(), newRegions);
 
     // 3. Move Table temp directory to the hbase root location
     final Path tableDir = FSUtils.getTableDir(mfs.getRootDir(), hTableDescriptor.getTableName());
     FileSystem fs = mfs.getFileSystem();
     if (!fs.delete(tableDir, true) && fs.exists(tableDir)) {
       throw new IOException("Couldn't delete " + tableDir);
     }
     if (!fs.rename(tempTableDir, tableDir)) {
       throw new IOException("Unable to move table from temp=" + tempTableDir +
         " to hbase root=" + tableDir);
     }
     return newRegions;
   }
 
   protected static List<HRegionInfo> addTableToMeta(final MasterProcedureEnv env,
       final HTableDescriptor hTableDescriptor,
       final List<HRegionInfo> regions) throws IOException {
     if (regions != null && regions.size() > 0) {
       ProcedureSyncWait.waitMetaRegions(env);
 
       // Add regions to META
       addRegionsToMeta(env, hTableDescriptor, regions);
       // Add replicas if needed
       List<HRegionInfo> newRegions = addReplicas(env, hTableDescriptor, regions);
 
       // Setup replication for region replicas if needed
       if (hTableDescriptor.getRegionReplication() > 1) {
         ServerRegionReplicaUtil.setupRegionReplicaReplication(env.getMasterConfiguration());
       }
       return newRegions;
     }
     return regions;
   }
 
   /**
    * Create any replicas for the regions (the default replicas that was
    * already created is passed to the method)
    * @param hTableDescriptor descriptor to use
    * @param regions default replicas
    * @return the combined list of default and non-default replicas
    */
   private static List<HRegionInfo> addReplicas(final MasterProcedureEnv env,
       final HTableDescriptor hTableDescriptor,
       final List<HRegionInfo> regions) {
     int numRegionReplicas = hTableDescriptor.getRegionReplication() - 1;
     if (numRegionReplicas <= 0) {
       return regions;
     }
     List<HRegionInfo> hRegionInfos =
         new ArrayList<HRegionInfo>((numRegionReplicas+1)*regions.size());
     for (int i = 0; i < regions.size(); i++) {
       for (int j = 1; j <= numRegionReplicas; j++) {
         hRegionInfos.add(RegionReplicaUtil.getRegionInfoForReplica(regions.get(i), j));
       }
     }
     hRegionInfos.addAll(regions);
     return hRegionInfos;
   }
 
   protected static void assignRegions(final MasterProcedureEnv env,
       final TableName tableName, final List<HRegionInfo> regions)
       throws HBaseException, IOException {
     ProcedureSyncWait.waitRegionServers(env);
 
     final AssignmentManager assignmentManager = env.getMasterServices().getAssignmentManager();
 
     // Mark the table as Enabling
     assignmentManager.getTableStateManager().setTableState(tableName,
         ZooKeeperProtos.Table.State.ENABLING);
 
     // Trigger immediate assignment of the regions in round-robin fashion
     ModifyRegionUtils.assignRegions(assignmentManager, regions);
 
     // Enable table
     assignmentManager.getTableStateManager()
       .setTableState(tableName, ZooKeeperProtos.Table.State.ENABLED);
   }
 
   /**
    * Add the specified set of regions to the hbase:meta table.
    */
   protected static void addRegionsToMeta(final MasterProcedureEnv env,
       final HTableDescriptor hTableDescriptor,
       final List<HRegionInfo> regionInfos) throws IOException {
     MetaTableAccessor.addRegionsToMeta(env.getMasterServices().getConnection(),
       regionInfos, hTableDescriptor.getRegionReplication());
   }
 
   protected static void updateTableDescCache(final MasterProcedureEnv env,
       final TableName tableName) throws IOException {
     env.getMasterServices().getTableDescriptors().get(tableName);
   }
 
   @Override
   protected boolean shouldWaitClientAck(MasterProcedureEnv env) {
     // system tables are created on bootstrap internally by the system
     // the client does not know about this procedures.
     return !getTableName().isSystemTable();
   }
 }