# ############################################################################
# Model: Direct SLU
# Encoder: Pre-trained ASR encoder -> LSTM
# Decoder: GRU + beamsearch
# Tokens: BPE with unigram
# losses: NLL
# Training: Fluent Speech Commands
# Authors:  Loren Lugosch, Mirco Ravanelli 2020
# ############################################################################

# Model parameters
sample_rate: 16000
emb_size: 128
dec_neurons: 512
output_neurons: 51 # index(eos/bos) = 0
ASR_encoder_dim: 512
encoder_dim: 256

# Decoding parameters
bos_index: 0
eos_index: 0
min_decode_ratio: 0.0
max_decode_ratio: 10.0
slu_beam_size: 80
eos_threshold: 1.5
temperature: 1.25

# Models
asr_model_source: speechbrain/asr-crdnn-rnnlm-librispeech

slu_enc: !new:speechbrain.nnet.containers.Sequential
    input_shape: [null, null, !ref <ASR_encoder_dim>]
    lstm: !new:speechbrain.nnet.RNN.LSTM
        input_size: !ref <ASR_encoder_dim>
        bidirectional: True
        hidden_size: !ref <encoder_dim>
        num_layers: 2
    linear: !new:speechbrain.nnet.linear.Linear
        input_size: !ref <encoder_dim> * 2
        n_neurons: !ref <encoder_dim>

output_emb: !new:speechbrain.nnet.embedding.Embedding
    num_embeddings: !ref <output_neurons>
    embedding_dim: !ref <emb_size>

dec: !new:speechbrain.nnet.RNN.AttentionalRNNDecoder
    enc_dim: !ref <encoder_dim>
    input_size: !ref <emb_size>
    rnn_type: gru
    attn_type: keyvalue
    hidden_size: !ref <dec_neurons>
    attn_dim: 512
    num_layers: 3
    scaling: 1.0
    dropout: 0.0

seq_lin: !new:speechbrain.nnet.linear.Linear
    input_size: !ref <dec_neurons>
    n_neurons: !ref <output_neurons>

model: !new:torch.nn.ModuleList
    - [!ref <slu_enc>, !ref <output_emb>,
       !ref <dec>, !ref <seq_lin>]

tokenizer: !new:sentencepiece.SentencePieceProcessor

pretrainer: !new:speechbrain.utils.parameter_transfer.Pretrainer
    loadables:
        model: !ref <model>
        tokenizer: !ref <tokenizer>

beam_searcher: !new:speechbrain.decoders.S2SRNNBeamSearcher
    embedding: !ref <output_emb>
    decoder: !ref <dec>
    linear: !ref <seq_lin>
    bos_index: !ref <bos_index>
    eos_index: !ref <eos_index>
    min_decode_ratio: !ref <min_decode_ratio>
    max_decode_ratio: !ref <max_decode_ratio>
    beam_size: !ref <slu_beam_size>
    eos_threshold: !ref <eos_threshold>
    temperature: !ref <temperature>
    using_max_attn_shift: False
    max_attn_shift: 30
    coverage_penalty: 0.

modules:
    slu_enc: !ref <slu_enc>
    beam_searcher: !ref <beam_searcher>