/*
 * Copyright DataStax, Inc.
 *
 * 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 com.datastax.oss.driver.api.core.cql;

import com.datastax.oss.driver.api.core.CqlIdentifier;
import com.datastax.oss.driver.api.core.data.AccessibleByName;
import com.datastax.oss.driver.api.core.detach.Detachable;
import com.datastax.oss.driver.internal.core.util.Loggers;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Collections;
import java.util.List;

/**
 * Metadata about a set of CQL columns.
 *
 * <p>The default implementation returned by the driver is immutable and serializable. If you write
 * your own implementation, it should at least be thread-safe; serializability is not mandatory, but
 * recommended for use with some 3rd-party tools like Apache Spark &trade;.
 */
public interface ColumnDefinitions extends Iterable<ColumnDefinition>, Detachable {

  /** @return the number of definitions contained in this metadata. */
  int size();

  /**
   * @param i the index to check.
   * @throws IndexOutOfBoundsException if the index is invalid.
   * @return the {@code i}th {@link ColumnDefinition} in this metadata.
   */
  @NonNull
  ColumnDefinition get(int i);

  /**
   * Get a definition by name.
   *
   * <p>This is the equivalent of:
   *
   * <pre>
   *   get(firstIndexOf(name))
   * </pre>
   *
   * @throws IllegalArgumentException if the name does not exist (in other words, if {@code
   *     !contains(name))}).
   * @see #contains(String)
   * @see #firstIndexOf(String)
   */
  @NonNull
  default ColumnDefinition get(@NonNull String name) {
    if (!contains(name)) {
      throw new IllegalArgumentException("No definition named " + name);
    } else {
      return get(firstIndexOf(name));
    }
  }

  /**
   * Get a definition by name.
   *
   * <p>This is the equivalent of:
   *
   * <pre>
   *   get(firstIndexOf(name))
   * </pre>
   *
   * @throws IllegalArgumentException if the name does not exist (in other words, if {@code
   *     !contains(name))}).
   * @see #contains(CqlIdentifier)
   * @see #firstIndexOf(CqlIdentifier)
   */
  @NonNull
  default ColumnDefinition get(@NonNull CqlIdentifier name) {
    if (!contains(name)) {
      throw new IllegalArgumentException("No definition named " + name);
    } else {
      return get(firstIndexOf(name));
    }
  }

  /**
   * Whether there is a definition using the given name.
   *
   * <p>Because raw strings are ambiguous with regard to case-sensitivity, the argument will be
   * interpreted according to the rules described in {@link AccessibleByName}.
   */
  boolean contains(@NonNull String name);

  /** Whether there is a definition using the given CQL identifier. */
  boolean contains(@NonNull CqlIdentifier id);

  /**
   * Returns the indices of all columns that use the given name.
   *
   * <p>Because raw strings are ambiguous with regard to case-sensitivity, the argument will be
   * interpreted according to the rules described in {@link AccessibleByName}.
   *
   * @return the indices, or an empty list if no column uses this name.
   * @apiNote the default implementation only exists for backward compatibility. It wraps the result
   *     of {@link #firstIndexOf(String)} in a singleton list, which is not entirely correct, as it
   *     will only return the first occurrence. Therefore it also logs a warning.
   *     <p>Implementors should always override this method (all built-in driver implementations
   *     do).
   */
  @NonNull
  default List<Integer> allIndicesOf(@NonNull String name) {
    Loggers.COLUMN_DEFINITIONS.warn(
        "{} should override allIndicesOf(String), the default implementation is a "
            + "workaround for backward compatibility, it only returns the first occurrence",
        getClass().getName());
    return Collections.singletonList(firstIndexOf(name));
  }

  /**
   * Returns the index of the first column that uses the given name.
   *
   * <p>Because raw strings are ambiguous with regard to case-sensitivity, the argument will be
   * interpreted according to the rules described in {@link AccessibleByName}.
   *
   * @return the index, or -1 if no column uses this name.
   */
  int firstIndexOf(@NonNull String name);

  /**
   * Returns the indices of all columns that use the given identifier.
   *
   * @return the indices, or an empty list if no column uses this identifier.
   * @apiNote the default implementation only exists for backward compatibility. It wraps the result
   *     of {@link #firstIndexOf(CqlIdentifier)} in a singleton list, which is not entirely correct,
   *     as it will only return the first occurrence. Therefore it also logs a warning.
   *     <p>Implementors should always override this method (all built-in driver implementations
   *     do).
   */
  @NonNull
  default List<Integer> allIndicesOf(@NonNull CqlIdentifier id) {
    Loggers.COLUMN_DEFINITIONS.warn(
        "{} should override allIndicesOf(CqlIdentifier), the default implementation is a "
            + "workaround for backward compatibility, it only returns the first occurrence",
        getClass().getName());
    return Collections.singletonList(firstIndexOf(id));
  }

  /**
   * Returns the index of the first column that uses the given identifier.
   *
   * @return the index, or -1 if no column uses this identifier.
   */
  int firstIndexOf(@NonNull CqlIdentifier id);
}
