/*
    * Copyright 2021 TiKV Project Authors.
    *
    * 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.
   *
   */
  
  package org.tikv.common.meta;
  
  import static java.util.Objects.requireNonNull;
  
  import com.fasterxml.jackson.annotation.JsonCreator;
  import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
  import com.fasterxml.jackson.annotation.JsonProperty;
  import com.google.common.annotations.VisibleForTesting;
  import com.google.common.base.Joiner;
  import com.google.common.collect.ImmutableList;
  import com.pingcap.tidb.tipb.ColumnInfo;
  import com.pingcap.tidb.tipb.IndexInfo;
  import java.io.Serializable;
  import java.util.List;
  import java.util.stream.Collectors;
  import org.tikv.common.exception.TiKVException;
  
  @JsonIgnoreProperties(ignoreUnknown = true)
  public class TiIndexInfo implements Serializable {
    private final long id;
    private final String name;
    private final String tableName;
    private final List<TiIndexColumn> indexColumns;
    private final boolean isUnique;
    private final boolean isPrimary;
    private final org.tikv.common.meta.SchemaState schemaState;
    private final String comment;
    private final org.tikv.common.meta.IndexType indexType;
    private final boolean isFakePrimaryKey;
  
    // default index column size (TypeFlag + Int64)
    private long indexColumnSize = 9;
  
    @JsonCreator
    @VisibleForTesting
    public TiIndexInfo(
        @JsonProperty("id") long id,
        @JsonProperty("idx_name") org.tikv.common.meta.CIStr name,
        @JsonProperty("tbl_name") org.tikv.common.meta.CIStr tableName,
        @JsonProperty("idx_cols") List<TiIndexColumn> indexColumns,
        @JsonProperty("is_unique") boolean isUnique,
        @JsonProperty("is_primary") boolean isPrimary,
        @JsonProperty("state") int schemaState,
        @JsonProperty("comment") String comment,
        @JsonProperty("index_type") int indexType,
        // This is a fake property and added JsonProperty only to
        // to bypass Jackson frameworks's check
        @JsonProperty("___isFakePrimaryKey") boolean isFakePrimaryKey) {
      this.id = id;
      this.name = requireNonNull(name, "index name is null").getL();
      this.tableName = requireNonNull(tableName, "table name is null").getL();
      this.indexColumns = ImmutableList.copyOf(requireNonNull(indexColumns, "indexColumns is null"));
      this.isUnique = isUnique;
      this.isPrimary = isPrimary;
      this.schemaState = org.tikv.common.meta.SchemaState.fromValue(schemaState);
      this.comment = comment;
      this.indexType = org.tikv.common.meta.IndexType.fromValue(indexType);
      this.isFakePrimaryKey = isFakePrimaryKey;
    }
  
    public static TiIndexInfo generateFakePrimaryKeyIndex(TiTableInfo table) {
      org.tikv.common.meta.TiColumnInfo pkColumn = table.getPKIsHandleColumn();
      if (pkColumn != null) {
        return new TiIndexInfo(
            -1,
            org.tikv.common.meta.CIStr.newCIStr("fake_pk_" + table.getId()),
            org.tikv.common.meta.CIStr.newCIStr(table.getName()),
            ImmutableList.of(pkColumn.toFakeIndexColumn()),
            true,
            true,
            org.tikv.common.meta.SchemaState.StatePublic.getStateCode(),
            "Fake Column",
            org.tikv.common.meta.IndexType.IndexTypeHash.getTypeCode(),
            true);
      }
      return null;
    }
  
    private long calculateIndexColumnSize(
        TiIndexColumn indexColumn, List<org.tikv.common.meta.TiColumnInfo> columns) {
      for (org.tikv.common.meta.TiColumnInfo column : columns) {
        if (column.getName().equalsIgnoreCase(indexColumn.getName())) {
         return column.getType().getSize();
       }
     }
     throw new TiKVException(
         String.format(
             "Index column [%s] not found in table [%s] columns [%s]",
             indexColumn.getName(), getTableName(), columns));
   }
 
   void calculateIndexSize(List<org.tikv.common.meta.TiColumnInfo> columns) {
     long ret = 0;
     for (TiIndexColumn indexColumn : indexColumns) {
       if (indexColumn.isLengthUnspecified()) {
         ret += calculateIndexColumnSize(indexColumn, columns);
       } else {
         ret += indexColumn.getLength();
       }
     }
     indexColumnSize = ret;
   }
 
   public long getIndexColumnSize() {
     return this.indexColumnSize;
   }
 
   public long getId() {
     return id;
   }
 
   public String getName() {
     return name;
   }
 
   public String getTableName() {
     return tableName;
   }
 
   public List<TiIndexColumn> getIndexColumns() {
     return indexColumns;
   }
 
   public boolean isUnique() {
     return isUnique;
   }
 
   public boolean isPrimary() {
     return isPrimary;
   }
 
   public org.tikv.common.meta.SchemaState getSchemaState() {
     return schemaState;
   }
 
   public String getComment() {
     return comment;
   }
 
   public org.tikv.common.meta.IndexType getIndexType() {
     return indexType;
   }
 
   public IndexInfo toProto(TiTableInfo tableInfo) {
     IndexInfo.Builder builder =
         IndexInfo.newBuilder().setTableId(tableInfo.getId()).setIndexId(id).setUnique(isUnique);
 
     List<org.tikv.common.meta.TiColumnInfo> columns = tableInfo.getColumns();
 
     for (TiIndexColumn indexColumn : getIndexColumns()) {
       int offset = indexColumn.getOffset();
       org.tikv.common.meta.TiColumnInfo column = columns.get(offset);
       builder.addColumns(column.toProto(tableInfo));
     }
 
     if (tableInfo.isPkHandle()) {
       for (org.tikv.common.meta.TiColumnInfo column : columns) {
         if (!column.isPrimaryKey()) {
           continue;
         }
         ColumnInfo pbColumn = column.toProto(tableInfo);
         builder.addColumns(pbColumn);
       }
     }
     return builder.build();
   }
 
   public boolean isFakePrimaryKey() {
     return isFakePrimaryKey;
   }
 
   @Override
   public String toString() {
     return String.format(
         "%s[%s]",
         name,
         Joiner.on(",")
             .skipNulls()
             .join(indexColumns.stream().map(TiIndexColumn::getName).collect(Collectors.toList())));
   }
 }