import argparse
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.asr.encoder.abs_encoder import AbsEncoder
from espnet2.asr.encoder.conformer_encoder import ConformerEncoder
from espnet2.asr.encoder.rnn_encoder import RNNEncoder
from espnet2.asr.encoder.transformer_encoder import TransformerEncoder
from espnet2.asr.frontend.abs_frontend import AbsFrontend
from espnet2.asr.frontend.default import DefaultFrontend
from espnet2.asr.frontend.windowing import SlidingWindow
from espnet2.diar.decoder.abs_decoder import AbsDecoder
from espnet2.diar.decoder.linear_decoder import LinearDecoder
from espnet2.diar.espnet_model import ESPnetDiarizationModel
from espnet2.layers.abs_normalize import AbsNormalize
from espnet2.layers.global_mvn import GlobalMVN
from espnet2.layers.label_aggregation import LabelAggregate
from espnet2.layers.utterance_mvn import UtteranceMVN
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 int_or_none
from espnet2.utils.types import str2bool
from espnet2.utils.types import str_or_none

frontend_choices = ClassChoices(
    name="frontend",
    classes=dict(default=DefaultFrontend, sliding_window=SlidingWindow),
    type_check=AbsFrontend,
    default="default",
)
normalize_choices = ClassChoices(
    "normalize",
    classes=dict(
        global_mvn=GlobalMVN,
        utterance_mvn=UtteranceMVN,
    ),
    type_check=AbsNormalize,
    default="utterance_mvn",
    optional=True,
)
label_aggregator_choices = ClassChoices(
    "label_aggregator",
    classes=dict(label_aggregator=LabelAggregate),
    default="label_aggregator",
)
encoder_choices = ClassChoices(
    "encoder",
    classes=dict(
        conformer=ConformerEncoder,
        transformer=TransformerEncoder,
        rnn=RNNEncoder,
    ),
    type_check=AbsEncoder,
    default="rnn",
)
decoder_choices = ClassChoices(
    "decoder",
    classes=dict(linear=LinearDecoder),
    type_check=AbsDecoder,
    default="linear",
)


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

    # Add variable objects configurations
    class_choices_list = [
        # --frontend and --frontend_conf
        frontend_choices,
        # --normalize and --normalize_conf
        normalize_choices,
        # --encoder and --encoder_conf
        encoder_choices,
        # --decoder and --decoder_conf
        decoder_choices,
        # --label_aggregator and --label_aggregator_conf
        label_aggregator_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):
        group = parser.add_argument_group(description="Task related")

        group.add_argument(
            "--num_spk",
            type=int_or_none,
            default=None,
            help="The number fo speakers (for each recording) used in system training",
        )

        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(
            "--input_size",
            type=int_or_none,
            default=None,
            help="The number of input dimension of the feature",
        )

        group.add_argument(
            "--model_conf",
            action=NestedDictAction,
            default=get_default_kwargs(ESPnetDiarizationModel),
            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",
        )

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

    @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()
        # NOTE(kamo): int value = 0 is reserved by CTC-blank symbol
        return CommonCollateFn(float_pad_value=0.0, int_pad_value=-1)

    @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:
            # FIXME (jiatong): add more arugment here
            retval = CommonPreprocessor(train=train)
        else:
            retval = None
        assert check_return_type(retval)
        return retval

    @classmethod
    def required_data_names(
        cls, train: bool = True, inference: bool = False
    ) -> Tuple[str, ...]:
        if not inference:
            retval = ("speech", "spk_labels")
        else:
            # Recognition mode
            retval = ("speech",)
        return retval

    @classmethod
    def optional_data_names(
        cls, train: bool = True, inference: bool = False
    ) -> Tuple[str, ...]:
        # (Note: jiatong): no optional data names for now
        retval = ()
        assert check_return_type(retval)
        return retval

    @classmethod
    def build_model(cls, args: argparse.Namespace) -> ESPnetDiarizationModel:
        assert check_argument_types()

        # 1. frontend
        if args.input_size is None:
            # Extract features in the model
            frontend_class = frontend_choices.get_class(args.frontend)
            frontend = frontend_class(**args.frontend_conf)
            input_size = frontend.output_size()
        else:
            # Give features from data-loader
            args.frontend = None
            args.frontend_conf = {}
            frontend = None
            input_size = args.input_size

        # 2. Normalization layer
        if args.normalize is not None:
            normalize_class = normalize_choices.get_class(args.normalize)
            normalize = normalize_class(**args.normalize_conf)
        else:
            normalize = None

        # 3. Label Aggregator layer
        label_aggregator_class = label_aggregator_choices.get_class(
            args.label_aggregator
        )
        label_aggregator = label_aggregator_class(**args.label_aggregator_conf)

        # 3. Encoder
        encoder_class = encoder_choices.get_class(args.encoder)
        # Note(jiatong): Diarization may not use subsampling when processing
        encoder = encoder_class(input_size=input_size, **args.encoder_conf)

        # 4. Decoder
        decoder_class = decoder_choices.get_class(args.decoder)
        decoder = decoder_class(
            num_spk=args.num_spk,
            encoder_output_size=encoder.output_size(),
            **args.decoder_conf,
        )

        # 5. Build model
        model = ESPnetDiarizationModel(
            frontend=frontend,
            normalize=normalize,
            label_aggregator=label_aggregator,
            encoder=encoder,
            decoder=decoder,
            **args.model_conf,
        )

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

        assert check_return_type(model)
        return model