#!/usr/bin/env python3
import argparse
import logging
import sys
from pathlib import Path
from typing import Any, List, Optional, Sequence, Tuple, Union

import numpy as np
import torch
from typeguard import check_argument_types, check_return_type

from espnet2.asr.maskctc_model import MaskCTCInference
from espnet2.fileio.datadir_writer import DatadirWriter
from espnet2.tasks.asr import ASRTask
from espnet2.text.build_tokenizer import build_tokenizer
from espnet2.text.token_id_converter import TokenIDConverter
from espnet2.torch_utils.device_funcs import to_device
from espnet2.torch_utils.set_all_random_seed import set_all_random_seed
from espnet2.utils import config_argparse
from espnet2.utils.types import str2bool, str2triple_str, str_or_none
from espnet.nets.beam_search import Hypothesis
from espnet.nets.pytorch_backend.transformer.subsampling import TooShortUttError
from espnet.utils.cli_utils import get_commandline_args


class Speech2Text:
    """Speech2Text class

    Examples:
        >>> import soundfile
        >>> speech2text = Speech2Text("asr_config.yml", "asr.pth")
        >>> audio, rate = soundfile.read("speech.wav")
        >>> speech2text(audio)
        [(text, token, token_int, hypothesis object), ...]

    """

    def __init__(
        self,
        asr_train_config: Union[Path, str],
        asr_model_file: Union[Path, str] = None,
        token_type: str = None,
        bpemodel: str = None,
        device: str = "cpu",
        batch_size: int = 1,
        dtype: str = "float32",
        maskctc_n_iterations: int = 10,
        maskctc_threshold_probability: float = 0.99,
    ):
        assert check_argument_types()

        # 1. Build ASR model
        asr_model, asr_train_args = ASRTask.build_model_from_file(
            asr_train_config, asr_model_file, device
        )
        asr_model.to(dtype=getattr(torch, dtype)).eval()
        token_list = asr_model.token_list

        s2t = MaskCTCInference(
            asr_model=asr_model,
            n_iterations=maskctc_n_iterations,
            threshold_probability=maskctc_threshold_probability,
        )
        s2t.to(device=device, dtype=getattr(torch, dtype)).eval()

        # 2. [Optional] Build Text converter: e.g. bpe-sym -> Text
        if token_type is None:
            token_type = asr_train_args.token_type
        if bpemodel is None:
            bpemodel = asr_train_args.bpemodel

        if token_type is None:
            tokenizer = None
        elif token_type == "bpe":
            if bpemodel is not None:
                tokenizer = build_tokenizer(token_type=token_type, bpemodel=bpemodel)
            else:
                tokenizer = None
        else:
            tokenizer = build_tokenizer(token_type=token_type)
        converter = TokenIDConverter(token_list=token_list)
        logging.info(f"Text tokenizer: {tokenizer}")

        self.asr_model = asr_model
        self.asr_train_args = asr_train_args
        self.s2t = s2t
        self.converter = converter
        self.tokenizer = tokenizer
        self.device = device
        self.dtype = dtype

    @torch.no_grad()
    def __call__(
        self, speech: Union[torch.Tensor, np.ndarray]
    ) -> List[Tuple[Optional[str], List[str], List[int], Hypothesis]]:
        """Inference

        Args:
            data: Input speech data
        Returns:
            text, token, token_int, hyp

        """
        assert check_argument_types()

        # Input as audio signal
        if isinstance(speech, np.ndarray):
            speech = torch.tensor(speech)

        # data: (Nsamples,) -> (1, Nsamples)
        speech = speech.unsqueeze(0).to(getattr(torch, self.dtype))
        # lenghts: (1,)
        lengths = speech.new_full([1], dtype=torch.long, fill_value=speech.size(1))
        batch = {"speech": speech, "speech_lengths": lengths}

        # a. To device
        batch = to_device(batch, device=self.device)

        # b. Forward Encoder
        enc, _ = self.asr_model.encode(**batch)
        if isinstance(enc, tuple):
            enc = enc[0]
        assert len(enc) == 1, len(enc)

        # c. Passed the encoder result and the inference algorithm
        hyp = self.s2t(enc[0])
        assert isinstance(hyp, Hypothesis), type(hyp)

        # remove sos/eos and get results
        token_int = hyp.yseq[1:-1].tolist()

        # remove blank symbol id, which is assumed to be 0
        token_int = list(filter(lambda x: x != 0, token_int))

        # Change integer-ids to tokens
        token = self.converter.ids2tokens(token_int)

        if self.tokenizer is not None:
            text = self.tokenizer.tokens2text(token)
        else:
            text = None
        results = [(text, token, token_int, hyp)]

        assert check_return_type(results)
        return results

    @staticmethod
    def from_pretrained(
        model_tag: Optional[str] = None,
        **kwargs: Optional[Any],
    ):
        """Build Speech2Text instance from the pretrained model.

        Args:
            model_tag (Optional[str]): Model tag of the pretrained models.
                Currently, the tags of espnet_model_zoo are supported.

        Returns:
            Speech2Text: Speech2Text instance.

        """
        if model_tag is not None:
            try:
                from espnet_model_zoo.downloader import ModelDownloader

            except ImportError:
                logging.error(
                    "`espnet_model_zoo` is not installed. "
                    "Please install via `pip install -U espnet_model_zoo`."
                )
                raise
            d = ModelDownloader()
            kwargs.update(**d.download_and_unpack(model_tag))

        return Speech2Text(**kwargs)


def inference(
    output_dir: str,
    batch_size: int,
    dtype: str,
    ngpu: int,
    seed: int,
    num_workers: int,
    log_level: Union[int, str],
    data_path_and_name_and_type: Sequence[Tuple[str, str, str]],
    key_file: Optional[str],
    asr_train_config: str,
    asr_model_file: str,
    model_tag: Optional[str],
    token_type: Optional[str],
    bpemodel: Optional[str],
    allow_variable_data_keys: bool,
    maskctc_n_iterations: int,
    maskctc_threshold_probability: float,
):
    assert check_argument_types()
    if batch_size > 1:
        raise NotImplementedError("batch decoding is not implemented")
    if ngpu > 1:
        raise NotImplementedError("only single GPU decoding is supported")

    logging.basicConfig(
        level=log_level,
        format="%(asctime)s (%(module)s:%(lineno)d) %(levelname)s: %(message)s",
    )

    if ngpu >= 1:
        device = "cuda"
    else:
        device = "cpu"

    # 1. Set random-seed
    set_all_random_seed(seed)

    # 2. Build speech2text
    speech2text_kwargs = dict(
        asr_train_config=asr_train_config,
        asr_model_file=asr_model_file,
        token_type=token_type,
        bpemodel=bpemodel,
        device=device,
        batch_size=batch_size,
        dtype=dtype,
        maskctc_n_iterations=maskctc_n_iterations,
        maskctc_threshold_probability=maskctc_threshold_probability,
    )
    speech2text = Speech2Text.from_pretrained(
        model_tag=model_tag,
        **speech2text_kwargs,
    )

    # 3. Build data-iterator
    loader = ASRTask.build_streaming_iterator(
        data_path_and_name_and_type,
        dtype=dtype,
        batch_size=batch_size,
        key_file=key_file,
        num_workers=num_workers,
        preprocess_fn=ASRTask.build_preprocess_fn(speech2text.asr_train_args, False),
        collate_fn=ASRTask.build_collate_fn(speech2text.asr_train_args, False),
        allow_variable_data_keys=allow_variable_data_keys,
        inference=True,
    )

    # 7 .Start for-loop
    with DatadirWriter(output_dir) as writer:
        for keys, batch in loader:
            assert isinstance(batch, dict), type(batch)
            assert all(isinstance(s, str) for s in keys), keys
            _bs = len(next(iter(batch.values())))
            assert len(keys) == _bs, f"{len(keys)} != {_bs}"
            batch = {k: v[0] for k, v in batch.items() if not k.endswith("_lengths")}

            try:
                results = speech2text(**batch)
            except TooShortUttError as e:
                logging.warning(f"Utterance {keys} {e}")
                hyp = Hypothesis(score=0.0, scores={}, states={}, yseq=[])
                results = [[" ", ["<space>"], [2], hyp]]

            # Only supporting batch_size==1
            key = keys[0]
            (text, token, token_int, hyp) = results[0]

            # Create a directory: outdir/{n}best_recog
            ibest_writer = writer["1best_recog"]

            # Write the result to each file
            ibest_writer["token"][key] = " ".join(token)
            ibest_writer["token_int"][key] = " ".join(map(str, token_int))
            ibest_writer["score"][key] = str(hyp.score)

            if text is not None:
                ibest_writer["text"][key] = text


def get_parser():
    parser = config_argparse.ArgumentParser(
        description="ASR Decoding",
        formatter_class=argparse.ArgumentDefaultsHelpFormatter,
    )

    # Note(kamo): Use '_' instead of '-' as separator.
    # '-' is confusing if written in yaml.
    parser.add_argument(
        "--log_level",
        type=lambda x: x.upper(),
        default="INFO",
        choices=("CRITICAL", "ERROR", "WARNING", "INFO", "DEBUG", "NOTSET"),
        help="The verbose level of logging",
    )

    parser.add_argument("--output_dir", type=str, required=True)
    parser.add_argument(
        "--ngpu",
        type=int,
        default=0,
        help="The number of gpus. 0 indicates CPU mode",
    )
    parser.add_argument("--seed", type=int, default=0, help="Random seed")
    parser.add_argument(
        "--dtype",
        default="float32",
        choices=["float16", "float32", "float64"],
        help="Data type",
    )
    parser.add_argument(
        "--num_workers",
        type=int,
        default=1,
        help="The number of workers used for DataLoader",
    )

    group = parser.add_argument_group("Input data related")
    group.add_argument(
        "--data_path_and_name_and_type",
        type=str2triple_str,
        required=True,
        action="append",
    )
    group.add_argument("--key_file", type=str_or_none)
    group.add_argument("--allow_variable_data_keys", type=str2bool, default=False)

    group = parser.add_argument_group("The model configuration related")
    group.add_argument("--asr_train_config", type=str, required=True)
    group.add_argument("--asr_model_file", type=str, required=True)
    group.add_argument(
        "--model_tag",
        type=str,
        help="Pretrained model tag. If specify this option, *_train_config and "
        "*_file will be overwritten",
    )

    group = parser.add_argument_group("Decoding related")
    group.add_argument(
        "--batch_size",
        type=int,
        default=1,
        help="The batch size for inference",
    )
    group.add_argument("--maskctc_n_iterations", type=int, default=10)
    group.add_argument("--maskctc_threshold_probability", type=float, default=0.99)

    group = parser.add_argument_group("Text converter related")
    group.add_argument(
        "--token_type",
        type=str_or_none,
        default=None,
        choices=["char", "bpe", None],
        help="The token type for ASR model. "
        "If not given, refers from the training args",
    )
    group.add_argument(
        "--bpemodel",
        type=str_or_none,
        default=None,
        help="The model path of sentencepiece. "
        "If not given, refers from the training args",
    )

    return parser


def main(cmd=None):
    print(get_commandline_args(), file=sys.stderr)
    parser = get_parser()
    args = parser.parse_args(cmd)
    kwargs = vars(args)
    kwargs.pop("config", None)

    inference(**kwargs)


if __name__ == "__main__":
    main()