#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ####################################################### #
# FunAutoSpeechRecognizer: https://github.com/alibaba-damo-academy/FunASR
# ####################################################### #
import io
import numpy as np
import base64
import wave
from funasr import AutoModel
from .base_stt import STTBase

def decode_str2bytes(data):
    # 将Base64编码的字节串解码为字节串
    if data is None:
        return None
    return base64.b64decode(data.encode('utf-8'))

class FunAutoSpeechRecognizer(STTBase):
    def __init__(self, 
                 model_path="paraformer-zh-streaming", 
                 device="cuda", 
                 RATE=16000, 
                 cfg_path=None, 
                 debug=False, 
                 chunk_ms=480, 
                 encoder_chunk_look_back=4, 
                 decoder_chunk_look_back=1, 
                 **kwargs):
        super().__init__(RATE=RATE, cfg_path=cfg_path, debug=debug)
        
        
        self.asr_model = AutoModel(model=model_path, device=device, **kwargs)
        
        self.encoder_chunk_look_back = encoder_chunk_look_back #number of chunks to lookback for encoder self-attention
        self.decoder_chunk_look_back = decoder_chunk_look_back #number of encoder chunks to lookback for decoder cross-attention
        
        #[0, 8, 4] 480ms, [0, 10, 5] 600ms
        if chunk_ms == 480:
            self.chunk_size = [0, 8, 4] 
        elif chunk_ms == 600:
            self.chunk_size = [0, 10, 5]
        else:
            raise ValueError("`chunk_ms` should be 480 or 600, and type is int.")
        self.chunk_partial_size = self.chunk_size[1] * 960
        self.audio_cache = {}
        self.asr_cache = {}

        # self.audio_cache = None
        # self.asr_cache = {}
        
        self._init_asr()
        
    def check_audio_type(self, audio_data):
        """check audio data type and convert it to bytes if necessary."""
        if isinstance(audio_data, bytes):
            pass
        elif isinstance(audio_data, list):
            audio_data = b''.join(audio_data)
        elif isinstance(audio_data, str):
            audio_data = decode_str2bytes(audio_data)
        elif isinstance(audio_data, io.BytesIO):
            wf = wave.open(audio_data, 'rb')
            audio_data = wf.readframes(wf.getnframes())
        elif isinstance(audio_data, np.ndarray):
            pass
        else:
            raise TypeError(f"audio_data must be bytes, list, str, \
                io.BytesIO or numpy array, but got {type(audio_data)}")
        
        if isinstance(audio_data, bytes):
            audio_data = np.frombuffer(audio_data, dtype=np.int16)
        elif isinstance(audio_data, np.ndarray):
            if audio_data.dtype != np.int16:
                audio_data = audio_data.astype(np.int16)
        else:
            raise TypeError(f"audio_data must be bytes or numpy array, but got {type(audio_data)}")
        return audio_data
    
    def _init_asr(self):
        # 随机初始化一段音频数据
        init_audio_data = np.random.randint(-32768, 32767, size=self.chunk_partial_size, dtype=np.int16)
        self.session_signup("init")
        self.asr_model.generate(input=init_audio_data, cache=self.asr_cache, is_final=False, chunk_size=self.chunk_size, encoder_chunk_look_back=self.encoder_chunk_look_back, decoder_chunk_look_back=self.decoder_chunk_look_back, session_id="init")
        self.session_signout("init")
        # print("init ASR model done.")
    
    # when chat trying to use asr , sign up
    def session_signup(self,session_id):
        self.audio_cache[session_id] = None
        self.asr_cache[session_id] = {}

    # when chat finish using asr , sign out
    def session_signout(self,session_id):
        del self.audio_cache[session_id]
        del self.asr_cache[session_id]

    def streaming_recognize(self,
                            session_id, 
                            audio_data, 
                            is_end=False, 
                            auto_det_end=False):
        """recognize partial result
        
        Args:
            audio_data: bytes or numpy array, partial audio data
            is_end: bool, whether the audio data is the end of a sentence
            auto_det_end: bool, whether to automatically detect the end of a audio data
        """
        text_dict = dict(text=[], is_end=is_end)

        audio_cache = self.audio_cache[session_id]
        
        audio_data = self.check_audio_type(audio_data)
        if audio_cache is None:
            audio_cache = audio_data
        else:
            if audio_cache.shape[0] > 0:
                audio_cache = np.concatenate([audio_cache, audio_data], axis=0)
        
        if not is_end and audio_cache.shape[0] < self.chunk_partial_size:
            self.audio_cache[session_id] = audio_cache
            return text_dict
        
        total_chunk_num = int((len(audio_cache)-1)/self.chunk_partial_size)
        
        if is_end:
            # if the audio data is the end of a sentence, \
            # we need to add one more chunk to the end to \
            # ensure the end of the sentence is recognized correctly.
            auto_det_end = True
        
        if auto_det_end:
            total_chunk_num += 1

        end_idx = None
        for i in range(total_chunk_num):
            if auto_det_end:
                is_end = i == total_chunk_num - 1
            start_idx = i*self.chunk_partial_size
            if auto_det_end:
                end_idx = (i+1)*self.chunk_partial_size if i < total_chunk_num-1 else -1
            else:
                end_idx = (i+1)*self.chunk_partial_size if i < total_chunk_num else -1
            # print(f"cut part: {start_idx}:{end_idx}, is_end: {is_end}, i: {i}, total_chunk_num: {total_chunk_num}")
            # t_stamp = time.time()
            
            speech_chunk = audio_cache[start_idx:end_idx]

            # TODO: exceptions processes
            # print("i:", i)
            try:
                res = self.asr_model.generate(input=speech_chunk, cache=self.asr_cache, is_final=is_end, chunk_size=self.chunk_size, encoder_chunk_look_back=self.encoder_chunk_look_back, decoder_chunk_look_back=self.decoder_chunk_look_back, session_id=session_id)
            except ValueError as e:
                print(f"ValueError: {e}")
                continue
            text_dict['text'].append(self.text_postprecess(res[0], data_id='text'))
            # print(f"each chunk time: {time.time()-t_stamp}")
            
        if is_end:
            audio_cache = None
        else:
            if end_idx:
                audio_cache = audio_cache[end_idx:] # cut the processed part from audio_cache
        text_dict['is_end'] = is_end
        
        
        self.audio_cache[session_id] = audio_cache
        return text_dict
    
    def streaming_recognize_origin(self,
                            session_id, 
                            audio_data, 
                            is_end=False, 
                            auto_det_end=False):
        """recognize partial result
        
        Args:
            audio_data: bytes or numpy array, partial audio data
            is_end: bool, whether the audio data is the end of a sentence
            auto_det_end: bool, whether to automatically detect the end of a audio data
        """
        text_dict = dict(text=[], is_end=is_end)

        audio_cache = self.audio_cache[session_id]
        asr_cache = self.asr_cache[session_id]
        
        audio_data = self.check_audio_type(audio_data)
        if audio_cache is None:
            audio_cache = audio_data
        else:
            if audio_cache.shape[0] > 0:
                audio_cache = np.concatenate([audio_cache, audio_data], axis=0)
        
        if not is_end and audio_cache.shape[0] < self.chunk_partial_size:
            self.audio_cache[session_id] = audio_cache
            return text_dict
        
        total_chunk_num = int((len(audio_cache)-1)/self.chunk_partial_size)
        
        if is_end:
            # if the audio data is the end of a sentence, \
            # we need to add one more chunk to the end to \
            # ensure the end of the sentence is recognized correctly.
            auto_det_end = True
        
        if auto_det_end:
            total_chunk_num += 1

        end_idx = None
        for i in range(total_chunk_num):
            if auto_det_end:
                is_end = i == total_chunk_num - 1
            start_idx = i*self.chunk_partial_size
            if auto_det_end:
                end_idx = (i+1)*self.chunk_partial_size if i < total_chunk_num-1 else -1
            else:
                end_idx = (i+1)*self.chunk_partial_size if i < total_chunk_num else -1
            # print(f"cut part: {start_idx}:{end_idx}, is_end: {is_end}, i: {i}, total_chunk_num: {total_chunk_num}")
            # t_stamp = time.time()
            
            speech_chunk = audio_cache[start_idx:end_idx]

            # TODO: exceptions processes
            try:
                res = self.asr_model.generate(input=speech_chunk, cache=asr_cache, is_final=is_end, chunk_size=self.chunk_size, encoder_chunk_look_back=self.encoder_chunk_look_back, decoder_chunk_look_back=self.decoder_chunk_look_back)
            except ValueError as e:
                print(f"ValueError: {e}")
                continue
            text_dict['text'].append(self.text_postprecess(res[0], data_id='text'))
            # print(f"each chunk time: {time.time()-t_stamp}")
            
        if is_end:
            audio_cache = None
            asr_cache = {}
        else:
            if end_idx:
                audio_cache = audio_cache[end_idx:] # cut the processed part from audio_cache
        text_dict['is_end'] = is_end
        
        
        self.audio_cache[session_id] = audio_cache
        self.asr_cache[session_id] = asr_cache
        return text_dict