#!/usr/bin/env python3
# -*- encoding: utf-8 -*-
# Copyright FunASR (https://github.com/alibaba-damo-academy/FunASR). All Rights Reserved.
#  MIT License  (https://opensource.org/licenses/MIT)

import torch
import types

from funasr.register import tables

def export_rebuild_model(model, **kwargs):
    is_onnx = kwargs.get("type", "onnx") == "onnx"
    encoder_class = tables.encoder_classes.get(kwargs["encoder"] + "Export")
    model.encoder = encoder_class(model.encoder, onnx=is_onnx)

    predictor_class = tables.predictor_classes.get(kwargs["predictor"] + "Export")
    model.predictor = predictor_class(model.predictor, onnx=is_onnx)

    decoder_class = tables.decoder_classes.get(kwargs["decoder"] + "Export")
    model.decoder = decoder_class(model.decoder, onnx=is_onnx)

    from funasr.utils.torch_function import sequence_mask

    model.make_pad_mask = sequence_mask(kwargs['max_seq_len'], flip=False)

    model.forward = types.MethodType(export_forward, model)
    model.export_dummy_inputs = types.MethodType(export_dummy_inputs, model)
    model.export_input_names = types.MethodType(export_input_names, model)
    model.export_output_names = types.MethodType(export_output_names, model)
    model.export_dynamic_axes = types.MethodType(export_dynamic_axes, model)
    model.export_name = types.MethodType(export_name, model)

    return model

def export_forward(
    self,
    speech: torch.Tensor,
    speech_lengths: torch.Tensor,
):
    # a. To device
    batch = {"speech": speech, "speech_lengths": speech_lengths}

    enc, enc_len = self.encoder(**batch)
    mask = self.make_pad_mask(enc_len)[:, None, :]
    pre_acoustic_embeds, pre_token_length, alphas, pre_peak_index = self.predictor(enc, mask)
    pre_token_length = pre_token_length.round().type(torch.int32)

    decoder_out, _ = self.decoder(enc, enc_len, pre_acoustic_embeds, pre_token_length)
    decoder_out = torch.log_softmax(decoder_out, dim=-1)

    # get predicted timestamps
    us_alphas, us_cif_peak = self.predictor.get_upsample_timestmap(enc, mask, pre_token_length)

    return decoder_out, pre_token_length, us_alphas, us_cif_peak

def export_dummy_inputs(self):
    speech = torch.randn(2, 30, 560)
    speech_lengths = torch.tensor([6, 30], dtype=torch.int32)
    return (speech, speech_lengths)

def export_input_names(self):
    return ['speech', 'speech_lengths']

def export_output_names(self):
    return ['logits', 'token_num', 'us_alphas', 'us_cif_peak']

def export_dynamic_axes(self):
    return {
        'speech': {
            0: 'batch_size',
            1: 'feats_length'
        },
        'speech_lengths': {
            0: 'batch_size',
        },
        'logits': {
            0: 'batch_size',
            1: 'logits_length'
        },
        'us_alphas': {
            0: 'batch_size',
            1: 'alphas_length'
        },
        'us_cif_peak': {
            0: 'batch_size',
            1: 'alphas_length'
        },
    }

def export_name(self):
    return "model.onnx"