/*
 * ToroDB
 * Copyright © 2014 8Kdata Technology (www.8kdata.com)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

package com.torodb.core.transaction.metainf;

import com.google.common.base.Preconditions;
import com.torodb.core.annotations.DoNotChange;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 *
 */
public class ImmutableMetaIdentifiedDocPartIndex extends AbstractMetaDocPartIndex implements
    MetaIdentifiedDocPartIndex {

  private final String identifier;
  private final Map<String, ImmutableMetaDocPartIndexColumn> columnsByIdentifier;
  private final List<ImmutableMetaDocPartIndexColumn> columnsByPosition;

  public ImmutableMetaIdentifiedDocPartIndex(String identifier, boolean unique) {
    this(identifier, unique, Collections.emptyList());
  }

  public ImmutableMetaIdentifiedDocPartIndex(String identifier, boolean unique,
      @DoNotChange List<ImmutableMetaDocPartIndexColumn> columns) {
    super(unique);
    this.identifier = identifier;
    this.columnsByPosition = columns;
    this.columnsByIdentifier = new HashMap<>();
    columns.forEach((column) -> columnsByIdentifier.put(column.getIdentifier(), column));
  }

  @Override
  public String getIdentifier() {
    return identifier;
  }

  @Override
  public int size() {
    return columnsByPosition.size();
  }

  @Override
  public Iterator<ImmutableMetaDocPartIndexColumn> iteratorColumns() {
    return columnsByPosition.iterator();
  }

  @Override
  public ImmutableMetaDocPartIndexColumn getMetaDocPartIndexColumnByPosition(int position) {
    return columnsByPosition.get(position);
  }

  @Override
  public ImmutableMetaDocPartIndexColumn getMetaDocPartIndexColumnByIdentifier(String columnName) {
    return columnsByIdentifier.get(columnName);
  }

  @Override
  public String toString() {
    return defautToString();
  }

  public static class Builder {

    private boolean built = false;
    private final String identifier;
    private final boolean unique;
    private final ArrayList<ImmutableMetaDocPartIndexColumn> columns;

    public Builder(String identifier, boolean unique) {
      this.identifier = identifier;
      this.unique = unique;
      this.columns = new ArrayList<>();
    }

    public Builder(ImmutableMetaIdentifiedDocPartIndex other) {
      this.identifier = other.getIdentifier();
      this.unique = other.isUnique();
      this.columns = new ArrayList<>(other.columnsByPosition);
    }

    public Builder(String identifier, boolean unique, int expectedColumns) {
      this.identifier = identifier;
      this.unique = unique;
      this.columns = new ArrayList<>(expectedColumns);
    }

    public Builder add(ImmutableMetaDocPartIndexColumn column) {
      Preconditions.checkState(!built, "This builder has already been built");
      Preconditions.checkState(column.getPosition() == columns.size(),
          "Column position is %s but was expected to be %s",
          column.getPosition(), columns.size());
      columns.add(column);
      return this;
    }

    public Builder addColumn(String identifier, FieldIndexOrdering ordering) {
      return add(new ImmutableMetaDocPartIndexColumn(columns.size(), identifier, ordering));
    }

    public ImmutableMetaIdentifiedDocPartIndex build() {
      Preconditions.checkState(!built, "This builder has already been built");
      built = true;
      return new ImmutableMetaIdentifiedDocPartIndex(identifier, unique, columns);
    }
  }

}