/*
 *  ******************************************************************************
 *  *
 *  *
 *  * This program and the accompanying materials are made available under the
 *  * terms of the Apache License, Version 2.0 which is available at
 *  * https://www.apache.org/licenses/LICENSE-2.0.
 *  *
 *  *  See the NOTICE file distributed with this work for additional
 *  *  information regarding copyright ownership.
 *  * 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.
 *  *
 *  * SPDX-License-Identifier: Apache-2.0
 *  *****************************************************************************
 */

package org.datavec.api.transform.sequence.window;

import org.datavec.api.transform.schema.Schema;
import org.datavec.api.writable.Writable;
import org.nd4j.shade.jackson.annotation.JsonInclude;
import org.nd4j.shade.jackson.annotation.JsonTypeInfo;

import java.io.Serializable;
import java.util.List;

@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
public interface WindowFunction extends Serializable {

    /**
     * Apply the windowing function to the given sequence
     * @param sequence the input sequence
     * @return the sequence with the window function applied
     */
    List<List<List<Writable>>> applyToSequence(List<List<Writable>> sequence);

    /**
     *
     * @param schema
     */
    void setInputSchema(Schema schema);

    /**
     *
     * @return
     */
    Schema getInputSchema();

    /** Get the output schema, given the input schema. Typically the output schema is the same as the input schema,
     * but not necessarily (for example, if the window function adds columns for the window start/end times)
     * @param inputSchema    Schema of the input data
     * @return Schema of the output windows
     */
    Schema transform(Schema inputSchema);


}
