/* ******************************************************************************
 *
 *
 * 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
 ******************************************************************************/

//
// @author AbdelRauf
//

#ifndef LIBND4J_HEADERS_DECODER_H
#define LIBND4J_HEADERS_DECODER_H
#include <ops/declarable/headers/common.h>

namespace sd {
namespace ops {

/**
 * Implementation of CTC beam search
 *
 * Input arrays:
 *    0: logits - logits NDArray logit NDArray {BATCH_LEN, MAX_FRAME_LEN, CLASS_LEN }. It should include a blank label
 * as well. type float 1: sequence_length -  NDArray {BATCH_LEN} length of frames. type integer
 *
 * Input integer arguments (IArgs):
 *    0: blank_index the index of the blank label in logits. default is last class. CLASS_LEN-1
 *    1: beam_width  the width of the beam search. default is 25
 *    2: nbest_len  the number of top best results that should be returned. default is 1
 *    NOTE:  if it is > beam_width it will be defaulted to beam_width size.
 * Input bool argument (BArgs):
 *    0: normalize_logit when its true it will normalize logits. by default it is assumed logit contains already
 * normalized log-probabilities Output array: 0: result_sequences NDArray {BATCH_LEN, NBEST, MAX_FRAME_LEN} result
 * sequences. NOTE: result_sequences NdArray should be c order and have ews == 1. type integer 1: result_probs NDArray
 * {BATCH_LEN, NBEST} negative log probabilities for each sequence. type float NOTE: result_probs NdArray should be c
 * order and have ews == 1 2: result_sequence_length NDArray {BATCH_LEN, NBEST} the length of the each sequence. type
 * integer NOTE: result_sequence_length NdArray should be c order and have ews == 1
 *
 *  NOTE:
 *   maximum value of integer indexing type should be >= CLASS_LEN to make sense. And also it should consider frame
 * lengthes as well. For now this case is mostly fine as only Indexing types are allowed as integer.
 */
#if NOT_EXCLUDED(OP_ctc_beam)
DECLARE_CUSTOM_OP(ctc_beam, 2, 3, false, 0, -2);
#endif

}  // namespace ops
}  // namespace sd

#endif