import asyncio
import json
from pathlib import Path

import asyncstdlib
import numpy as np
import pandas as pd
from pydub import AudioSegment

from stf_alternative.compose import get_compose_func_without_keying, get_keying_func
from stf_alternative.dataset import LipGanAudio, LipGanImage, LipGanRemoteImage
from stf_alternative.inference import (
    adictzip,
    ainference_model_remote,
    audio_encode,
    dictzip,
    get_head_box,
    inference_model,
    inference_model_remote,
)
from stf_alternative.preprocess_dir.utils import face_finder as ff
from stf_alternative.readers import (
    AsyncProcessPoolBatchIterator,
    ProcessPoolBatchIterator,
    get_image_folder_async_process_reader,
    get_image_folder_process_reader,
)
from stf_alternative.util import (
    acycle,
    get_crop_mp4_dir,
    get_frame_dir,
    get_preprocess_dir,
    icycle,
    read_config,
)


def calc_audio_std(audio_segment):
    sample = np.array(audio_segment.get_array_of_samples(), dtype=np.int16)
    max_value = np.iinfo(
        np.int8
        if audio_segment.sample_width == 1
        else np.int16
        if audio_segment.sample_width == 2
        else np.int32
    ).max
    return sample.std() / max_value, len(sample)


class RunningAudioNormalizer:
    def __init__(self, ref_audio_segment, decay_rate=0.01):
        self.ref_std, _ = calc_audio_std(ref_audio_segment)
        self.running_var = np.float64(0)
        self.running_cnt = 0
        self.decay_rate = decay_rate

    def __call__(self, audio_segment):
        std, cnt = calc_audio_std(audio_segment)
        self.running_var = (self.running_var + (std**2) * cnt) * (1 - self.decay_rate)
        self.running_cnt = (self.running_cnt + cnt) * (1 - self.decay_rate)

        return audio_segment._spawn(
            (audio_segment.get_array_of_samples() / self.std * self.ref_std)
            .astype(np.int16)
            .tobytes()
        )

    @property
    def std(self):
        return np.sqrt(self.running_var / self.running_cnt)


def get_video_metadata(preprocess_dir):
    json_path = preprocess_dir / "metadata.json"
    with open(json_path, "r") as f:
        return json.load(f)


class Template:
    def __init__(
        self,
        config_path,
        model,
        template_video_path,
        wav_std=False,
        ref_wav=None,
        verbose=False,
    ):
        self.config = read_config(config_path)
        self.model = model

        self.template_video_path = Path(template_video_path)
        self.preprocess_dir = Path(
            get_preprocess_dir(model.work_root_path, model.args.name)
        )

        self.crop_mp4_dir = Path(
            get_crop_mp4_dir(self.preprocess_dir, template_video_path)
        )
        self.dataset_dir = self.crop_mp4_dir / f"{Path(template_video_path).stem}_000"

        self.template_frames_path = Path(
            get_frame_dir(self.preprocess_dir, template_video_path, ratio=1.0)
        )
        self.verbose = verbose
        self.remote = self.model.args.model_type == "remote"

        self.audio_normalizer = (
            RunningAudioNormalizer(ref_wav) if wav_std else lambda x: x
        )
        self.df = pd.read_pickle(self.dataset_dir / "df_fan.pickle")

        metadata = get_video_metadata(self.preprocess_dir)
        self.fps = metadata["fps"]
        self.width, self.height = metadata["width"], metadata["height"]

        self.keying_func = get_keying_func(self)
        self.compose_func = get_compose_func_without_keying(self, ratio=1.0)

        self.move = "move" in self.config.keys() and self.config.move

        self.inference_func = inference_model_remote if self.remote else inference_model
        self.batch_size = self.model.args.batch_size
        self.unit = 1000 / self.fps

    def _get_reader(self, num_skip_frames):
        assert self.template_frames_path.exists()
        return get_image_folder_process_reader(
            data_path=self.template_frames_path,
            num_skip_frames=num_skip_frames,
            preload=self.batch_size,
        )

    def _get_local_face_dataset(self, num_skip_frames):
        return LipGanImage(
            args=self.model.args,
            path=self.dataset_dir,
            num_skip_frames=num_skip_frames,
        )

    def _get_remote_face_dataset(self, num_skip_frames):
        return LipGanRemoteImage(
            args=self.model.args,
            path=self.dataset_dir,
            num_skip_frames=num_skip_frames,
        )

    def _get_mel_dataset(self, audio_segment):
        image_count = round(
            audio_segment.duration_seconds * self.fps
        )  # 패딩 했기 때문에 batch_size로 나뉜다
        ids = list(range(image_count))

        mel = audio_encode(
            model=self.model,
            audio_segment=audio_segment,
            device=self.model.device,
        )

        return LipGanAudio(
            args=self.model.args,
            id_list=ids,
            mel=mel,
            fps=self.fps,
        )

    def _get_face_dataset(self, num_skip_frames):
        if self.remote:
            return self._get_remote_face_dataset(num_skip_frames=num_skip_frames)
        else:
            return self._get_local_face_dataset(num_skip_frames=num_skip_frames)

    def _wrap_reader(self, reader):
        reader = icycle(reader)
        return reader

    def _wrap_dataset(self, dataset):
        dataloader = ProcessPoolBatchIterator(
            dataset=dataset,
            batch_size=self.batch_size,
        )
        return dataloader

    def get_reader(self, num_skip_frames=0):
        reader = self._get_reader(num_skip_frames=num_skip_frames)
        reader = self._wrap_reader(reader)
        return reader

    def get_mel_loader(self, audio_segment):
        mel_dataset = self._get_mel_dataset(audio_segment)
        return self._wrap_dataset(mel_dataset)

    def get_face_loader(self, num_skip_frames=0):
        face_dataset = self._get_face_dataset(num_skip_frames=num_skip_frames)
        return self._wrap_dataset(face_dataset)  # need cycle

    # padding according to batch size.
    def pad(self, audio_segment):
        num_frames = audio_segment.duration_seconds * self.fps
        pad = AudioSegment.silent(
            (self.batch_size - (num_frames % self.batch_size)) * (1000 / self.fps)
        )
        return audio_segment + pad

    def _prepare_data(
        self,
        audio_segment,
        video_start_offset_frame,
    ):
        video_start_offset_frame = video_start_offset_frame % len(self.df)
        padded = self.pad(audio_segment)

        face_dataset = self._get_face_dataset(num_skip_frames=video_start_offset_frame)
        mel_dataset = self._get_mel_dataset(audio_segment=padded)

        n_frames = len(mel_dataset)
        assert n_frames % self.batch_size == 0

        face_loader = self._wrap_dataset(face_dataset)
        mel_loader = self._wrap_dataset(mel_dataset)
        return padded, face_loader, mel_loader

    def gen_infer(
        self,
        audio_segment,
        video_start_offset_frame,
    ):
        padded, face_loader, mel_loader = self._prepare_data(
            audio_segment=audio_segment,
            video_start_offset_frame=video_start_offset_frame,
        )

        for i, v in enumerate(dictzip(iter(mel_loader), iter(face_loader))):
            inferred = self.inference_func(self.model, v, self.model.device)

            for j, it in enumerate(inferred):
                chunk_pivot = i * self.unit * self.batch_size + j * self.unit
                chunk = padded[chunk_pivot : chunk_pivot + self.unit]
                yield it, chunk

    def gen_infer_batch(
        self,
        audio_segment,
        video_start_offset_frame,
    ):
        padded, face_loader, mel_loader = self._prepare_data(
            audio_segment=audio_segment,
            video_start_offset_frame=video_start_offset_frame,
        )

        for i, v in enumerate(dictzip(iter(mel_loader), iter(face_loader))):
            inferred = self.inference_func(self.model, v, self.model.device)
            yield inferred, padded[
                i * self.unit * self.batch_size : (i + 1) * self.unit * self.batch_size
            ]

    def gen_infer_batch_future(
        self,
        pool,
        audio_segment,
        video_start_offset_frame,
    ):
        padded, face_loader, mel_loader = self._prepare_data(
            audio_segment=audio_segment,
            video_start_offset_frame=video_start_offset_frame,
        )

        futures = []
        for i, v in enumerate(dictzip(iter(mel_loader), iter(face_loader))):
            futures.append(
                pool.submit(self.inference_func, self.model, v, self.model.device)
            )

        for i, future in enumerate(futures):
            yield future, padded[
                i * self.unit * self.batch_size : (i + 1) * self.unit * self.batch_size
            ]

    def gen_infer_concurrent(
        self,
        pool,
        audio_segment,
        video_start_offset_frame,
    ):
        for future, chunk in self.gen_infer_batch_future(
            pool, audio_segment, video_start_offset_frame
        ):
            for i, inferred in enumerate(future.result()):
                yield inferred, chunk[i * self.unit : (i + 1) * self.unit]

    def compose(
        self,
        idx,
        frame,
        output,
    ):
        head_box_idx = idx % len(self.df)
        head_box = get_head_box(
            self.df,
            move=self.move,
            head_box_idx=head_box_idx,
        )
        alpha2 = self.keying_func(output, head_box_idx, head_box)
        frame = self.compose_func(alpha2, frame[:, :, :4], head_box_idx)
        return frame

    def gen_frames(
        self,
        audio_segment,
        video_start_offset_frame,
        reader=None,
    ):
        reader = reader or self.get_reader(num_skip_frames=video_start_offset_frame)
        gen_infer = self.gen_infer(audio_segment, video_start_offset_frame)

        for idx, ((o, a), f) in enumerate(
            zip(gen_infer, reader), video_start_offset_frame
        ):
            composed = self.compose(idx, f, o)
            yield composed, a

    def gen_frames_concurrent(
        self,
        pool,
        audio_segment,
        video_start_offset_frame,
        reader=None,
    ):
        reader = reader or self.get_reader(num_skip_frames=video_start_offset_frame)
        gen_infer = self.gen_infer_concurrent(
            pool,
            audio_segment,
            video_start_offset_frame,
        )

        for idx, ((o, a), f) in enumerate(
            zip(gen_infer, reader), video_start_offset_frame
        ):
            yield self.compose(idx, f, o), a


class AsyncTemplate(Template):
    async def agen_infer_batch_future(
        self,
        pool,
        audio_segment,
        video_start_offset_frame,
    ):
        assert self.remote

        padded, face_loader, mel_loader = await self._aprepare_data(
            pool,
            audio_segment=audio_segment,
            video_start_offset_frame=video_start_offset_frame,
        )

        futures = []
        async for i, v in asyncstdlib.enumerate(
            adictzip(aiter(mel_loader), aiter(face_loader))
        ):
            futures.append(
                asyncio.create_task(
                    ainference_model_remote(pool, self.model, v, self.model.device)
                )
            )

        for i, future in enumerate(futures):
            yield future, padded[
                i * self.unit * self.batch_size : (i + 1) * self.unit * self.batch_size
            ]

    async def _awrap_dataset(self, dataset):
        dataloader = AsyncProcessPoolBatchIterator(
            dataset=dataset,
            batch_size=self.batch_size,
        )
        return dataloader

    async def _aprepare_data(
        self,
        pool,
        audio_segment,
        video_start_offset_frame,
    ):
        video_start_offset_frame = video_start_offset_frame % len(self.df)
        padded = self.pad(audio_segment)

        loop = asyncio.get_running_loop()

        face_dataset, mel_dataset = await asyncio.gather(
            loop.run_in_executor(
                pool, self._get_face_dataset, video_start_offset_frame
            ),
            loop.run_in_executor(pool, self._get_mel_dataset, padded),
        )

        n_frames = len(mel_dataset)
        assert n_frames % self.batch_size == 0

        face_loader = await self._awrap_dataset(face_dataset)
        mel_loader = await self._awrap_dataset(mel_dataset)
        return padded, face_loader, mel_loader

    def _aget_reader(self, num_skip_frames):
        assert self.template_frames_path.exists()
        return get_image_folder_async_process_reader(
            data_path=self.template_frames_path,
            num_skip_frames=num_skip_frames,
            preload=self.batch_size,
        )

    def _awrap_reader(self, reader):
        reader = acycle(reader)
        return reader

    def aget_reader(self, num_skip_frames=0):
        reader = self._aget_reader(num_skip_frames=num_skip_frames)
        reader = self._awrap_reader(reader)
        return reader