import argparse
import logging
from typing import Callable
from typing import Collection
from typing import Dict
from typing import List
from typing import Optional
from typing import Tuple

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

from espnet2.lm.abs_model import AbsLM
from espnet2.lm.espnet_model import ESPnetLanguageModel
from espnet2.lm.seq_rnn_lm import SequentialRNNLM
from espnet2.lm.transformer_lm import TransformerLM
from espnet2.tasks.abs_task import AbsTask
from espnet2.torch_utils.initialize import initialize
from espnet2.train.class_choices import ClassChoices
from espnet2.train.collate_fn import CommonCollateFn
from espnet2.train.preprocessor import CommonPreprocessor
from espnet2.train.trainer import Trainer
from espnet2.utils.get_default_kwargs import get_default_kwargs
from espnet2.utils.nested_dict_action import NestedDictAction
from espnet2.utils.types import str2bool
from espnet2.utils.types import str_or_none


lm_choices = ClassChoices(
    "lm",
    classes=dict(
        seq_rnn=SequentialRNNLM,
        transformer=TransformerLM,
    ),
    type_check=AbsLM,
    default="seq_rnn",
)


class LMTask(AbsTask):
    # If you need more than one optimizers, change this value
    num_optimizers: int = 1

    # Add variable objects configurations
    class_choices_list = [lm_choices]

    # If you need to modify train() or eval() procedures, change Trainer class here
    trainer = Trainer

    @classmethod
    def add_task_arguments(cls, parser: argparse.ArgumentParser):
        # NOTE(kamo): Use '_' instead of '-' to avoid confusion
        assert check_argument_types()
        group = parser.add_argument_group(description="Task related")

        # NOTE(kamo): add_arguments(..., required=True) can't be used
        # to provide --print_config mode. Instead of it, do as
        required = parser.get_default("required")
        required += ["token_list"]

        group.add_argument(
            "--token_list",
            type=str_or_none,
            default=None,
            help="A text mapping int-id to token",
        )
        group.add_argument(
            "--init",
            type=lambda x: str_or_none(x.lower()),
            default=None,
            help="The initialization method",
            choices=[
                "chainer",
                "xavier_uniform",
                "xavier_normal",
                "kaiming_uniform",
                "kaiming_normal",
                None,
            ],
        )
        group.add_argument(
            "--model_conf",
            action=NestedDictAction,
            default=get_default_kwargs(ESPnetLanguageModel),
            help="The keyword arguments for model class.",
        )

        group = parser.add_argument_group(description="Preprocess related")
        group.add_argument(
            "--use_preprocessor",
            type=str2bool,
            default=True,
            help="Apply preprocessing to data or not",
        )
        group.add_argument(
            "--token_type",
            type=str,
            default="bpe",
            choices=["bpe", "char", "word"],
            help="",
        )
        group.add_argument(
            "--bpemodel",
            type=str_or_none,
            default=None,
            help="The model file fo sentencepiece",
        )
        parser.add_argument(
            "--non_linguistic_symbols",
            type=str_or_none,
            help="non_linguistic_symbols file path",
        )
        parser.add_argument(
            "--cleaner",
            type=str_or_none,
            choices=[None, "tacotron", "jaconv", "vietnamese"],
            default=None,
            help="Apply text cleaning",
        )
        parser.add_argument(
            "--g2p",
            type=str_or_none,
            choices=[None, "g2p_en", "pyopenjtalk", "pyopenjtalk_kana"],
            default=None,
            help="Specify g2p method if --token_type=phn",
        )

        for class_choices in cls.class_choices_list:
            # Append --<name> and --<name>_conf.
            # e.g. --encoder and --encoder_conf
            class_choices.add_arguments(group)

        assert check_return_type(parser)
        return parser

    @classmethod
    def build_collate_fn(
        cls, args: argparse.Namespace, train: bool
    ) -> Callable[
        [Collection[Tuple[str, Dict[str, np.ndarray]]]],
        Tuple[List[str], Dict[str, torch.Tensor]],
    ]:
        assert check_argument_types()
        return CommonCollateFn(int_pad_value=0)

    @classmethod
    def build_preprocess_fn(
        cls, args: argparse.Namespace, train: bool
    ) -> Optional[Callable[[str, Dict[str, np.array]], Dict[str, np.ndarray]]]:
        assert check_argument_types()
        if args.use_preprocessor:
            retval = CommonPreprocessor(
                train=train,
                token_type=args.token_type,
                token_list=args.token_list,
                bpemodel=args.bpemodel,
                text_cleaner=args.cleaner,
                g2p_type=args.g2p,
                non_linguistic_symbols=args.non_linguistic_symbols,
            )
        else:
            retval = None
        assert check_return_type(retval)
        return retval

    @classmethod
    def required_data_names(
        cls, train: bool = True, inference: bool = False
    ) -> Tuple[str, ...]:
        retval = ("text",)
        return retval

    @classmethod
    def optional_data_names(
        cls, train: bool = True, inference: bool = False
    ) -> Tuple[str, ...]:
        retval = ()
        return retval

    @classmethod
    def build_model(cls, args: argparse.Namespace) -> ESPnetLanguageModel:
        assert check_argument_types()
        if isinstance(args.token_list, str):
            with open(args.token_list, encoding="utf-8") as f:
                token_list = [line.rstrip() for line in f]

            # "args" is saved as it is in a yaml file by BaseTask.main().
            # Overwriting token_list to keep it as "portable".
            args.token_list = token_list.copy()
        elif isinstance(args.token_list, (tuple, list)):
            token_list = args.token_list.copy()
        else:
            raise RuntimeError("token_list must be str or dict")

        vocab_size = len(token_list)
        logging.info(f"Vocabulary size: {vocab_size }")

        # 1. Build LM model
        lm_class = lm_choices.get_class(args.lm)
        lm = lm_class(vocab_size=vocab_size, **args.lm_conf)

        # 2. Build ESPnetModel
        # Assume the last-id is sos_and_eos
        model = ESPnetLanguageModel(lm=lm, vocab_size=vocab_size, **args.model_conf)

        # FIXME(kamo): Should be done in model?
        # 3. Initialize
        if args.init is not None:
            initialize(model, args.init)

        assert check_return_type(model)
        return model