# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import base64
import io

import librosa
import numpy as np
import paddle
import soundfile as sf
from scipy.io import wavfile

from paddlespeech.cli.log import logger
from paddlespeech.cli.tts.infer import TTSExecutor
from paddlespeech.server.engine.base_engine import BaseEngine
from paddlespeech.server.utils.audio_process import change_speed
from paddlespeech.server.utils.config import get_config
from paddlespeech.server.utils.errors import ErrorCode
from paddlespeech.server.utils.exception import ServerBaseException

__all__ = ['TTSEngine']


class TTSServerExecutor(TTSExecutor):
    def __init__(self):
        super().__init__()
        pass


class TTSEngine(BaseEngine):
    """TTS server engine

    Args:
        metaclass: Defaults to Singleton.
    """

    def __init__(self, name=None):
        """Initialize TTS server engine
        """
        super(TTSEngine, self).__init__()

    def init(self, config_file: str) -> bool:
        self.executor = TTSServerExecutor()

        try:
            self.config = get_config(config_file)
            paddle.set_device(self.config.device)

            self.executor._init_from_path(
                am=self.config.am,
                am_config=self.config.am_config,
                am_ckpt=self.config.am_ckpt,
                am_stat=self.config.am_stat,
                phones_dict=self.config.phones_dict,
                tones_dict=self.config.tones_dict,
                speaker_dict=self.config.speaker_dict,
                voc=self.config.voc,
                voc_config=self.config.voc_config,
                voc_ckpt=self.config.voc_ckpt,
                voc_stat=self.config.voc_stat,
                lang=self.config.lang)
        except:
            logger.info("Initialize TTS server engine Failed.")
            return False

        logger.info("Initialize TTS server engine successfully.")
        return True

    def postprocess(self,
                    wav,
                    original_fs: int,
                    target_fs: int=16000,
                    volume: float=1.0,
                    speed: float=1.0,
                    audio_path: str=None):
        """Post-processing operations, including speech, volume, sample rate, save audio file

        Args:
            wav (numpy(float)): Synthesized audio sample points
            original_fs (int): original audio sample rate
            target_fs (int): target audio sample rate
            volume (float): target volume
            speed (float): target speed

        Raises:
            ServerBaseException: Throws an exception if the change speed unsuccessfully.

        Returns:
            target_fs: target sample rate for synthesized audio.
            wav_base64: The base64 format of the synthesized audio.
        """

        # transform sample_rate
        if target_fs == 0 or target_fs > original_fs:
            target_fs = original_fs
            wav_tar_fs = wav
        else:
            wav_tar_fs = librosa.resample(
                np.squeeze(wav), original_fs, target_fs)

        # transform volume
        wav_vol = wav_tar_fs * volume

        # transform speed
        try:  # windows not support soxbindings
            wav_speed = change_speed(wav_vol, speed, target_fs)
        except:
            raise ServerBaseException(
                ErrorCode.SERVER_INTERNAL_ERR,
                "Can not install soxbindings on your system.")

        # wav to base64
        buf = io.BytesIO()
        wavfile.write(buf, target_fs, wav_speed)
        base64_bytes = base64.b64encode(buf.read())
        wav_base64 = base64_bytes.decode('utf-8')

        # save audio
        if audio_path is not None and audio_path.endswith(".wav"):
            sf.write(audio_path, wav_speed, target_fs)
        elif audio_path is not None and audio_path.endswith(".pcm"):
            wav_norm = wav_speed * (32767 / max(0.001,
                                                np.max(np.abs(wav_speed))))
            with open(audio_path, "wb") as f:
                f.write(wav_norm.astype(np.int16))

        return target_fs, wav_base64

    def run(self,
            sentence: str,
            spk_id: int=0,
            speed: float=1.0,
            volume: float=1.0,
            sample_rate: int=0,
            save_path: str=None):
        """ run include inference and postprocess.

        Args:
            sentence (str): text to be synthesized
            spk_id (int, optional): speaker id for multi-speaker speech synthesis. Defaults to 0.
            speed (float, optional): speed. Defaults to 1.0.
            volume (float, optional): volume. Defaults to 1.0.
            sample_rate (int, optional): target sample rate for synthesized audio, 
            0 means the same as the model sampling rate. Defaults to 0.
            save_path (str, optional): The save path of the synthesized audio. 
            None means do not save audio. Defaults to None.

        Raises:
            ServerBaseException: Throws an exception if tts inference unsuccessfully.
            ServerBaseException: Throws an exception if postprocess unsuccessfully.

        Returns:
            lang: model language 
            target_sample_rate: target sample rate for synthesized audio.
            wav_base64: The base64 format of the synthesized audio.
        """

        lang = self.config.lang

        try:
            self.executor.infer(
                text=sentence, lang=lang, am=self.config.am, spk_id=spk_id)
        except:
            raise ServerBaseException(ErrorCode.SERVER_INTERNAL_ERR,
                                      "tts infer failed.")

        try:
            target_sample_rate, wav_base64 = self.postprocess(
                wav=self.executor._outputs['wav'].numpy(),
                original_fs=self.executor.am_config.fs,
                target_fs=sample_rate,
                volume=volume,
                speed=speed,
                audio_path=save_path)
        except:
            raise ServerBaseException(ErrorCode.SERVER_INTERNAL_ERR,
                                      "tts postprocess failed.")

        return lang, target_sample_rate, wav_base64