import time
import numpy as np
import torch
import torch.nn.functional as F
from transformers import AutoModelForCTC, AutoProcessor, Wav2Vec2Processor, HubertModel


import queue
from queue import Queue
#from collections import deque
from threading import Thread, Event

from baseasr import BaseASR

class NerfASR(BaseASR):
    def __init__(self, opt, parent):
        super().__init__(opt,parent)

        self.device = 'cuda' if torch.cuda.is_available() else 'cpu'
        if 'esperanto' in self.opt.asr_model:
            self.audio_dim = 44
        elif 'deepspeech' in self.opt.asr_model:
            self.audio_dim = 29
        elif 'hubert' in self.opt.asr_model:
            self.audio_dim = 1024
        else:
            self.audio_dim = 32

        # prepare context cache
        # each segment is (stride_left + ctx + stride_right) * 20ms, latency should be (ctx + stride_right) * 20ms
        self.context_size = opt.m
        self.stride_left_size = opt.l
        self.stride_right_size = opt.r

        # pad left frames
        if self.stride_left_size > 0:
            self.frames.extend([np.zeros(self.chunk, dtype=np.float32)] * self.stride_left_size)

        # create wav2vec model
        print(f'[INFO] loading ASR model {self.opt.asr_model}...')
        if 'hubert' in self.opt.asr_model:
            self.processor = Wav2Vec2Processor.from_pretrained(opt.asr_model)
            self.model = HubertModel.from_pretrained(opt.asr_model).to(self.device) 
        else:   
            self.processor = AutoProcessor.from_pretrained(opt.asr_model)
            self.model = AutoModelForCTC.from_pretrained(opt.asr_model).to(self.device)

        # the extracted features 
        # use a loop queue to efficiently record endless features: [f--t---][-------][-------]
        self.feat_buffer_size = 4
        self.feat_buffer_idx = 0
        self.feat_queue = torch.zeros(self.feat_buffer_size * self.context_size, self.audio_dim, dtype=torch.float32, device=self.device)

        # TODO: hard coded 16 and 8 window size...
        self.front = self.feat_buffer_size * self.context_size - 8 # fake padding
        self.tail = 8
        # attention window...
        self.att_feats = [torch.zeros(self.audio_dim, 16, dtype=torch.float32, device=self.device)] * 4 # 4 zero padding...

        # warm up steps needed: mid + right + window_size + attention_size
        self.warm_up_steps = self.context_size + self.stride_left_size + self.stride_right_size #+ self.stride_left_size   #+ 8 + 2 * 3

    def get_audio_frame(self):         
        try:
            frame = self.queue.get(block=False)
            type = 0
            #print(f'[INFO] get frame {frame.shape}')
        except queue.Empty:
            if self.parent and self.parent.curr_state>1: #播放自定义音频
                frame = self.parent.get_audio_stream(self.parent.curr_state)
                type = self.parent.curr_state
            else:
                frame = np.zeros(self.chunk, dtype=np.float32)
                type = 1

        return frame,type

    def get_next_feat(self): #get audio embedding to nerf
        # return a [1/8, 16] window, for the next input to nerf side.
        if self.opt.att>0:
            while len(self.att_feats) < 8:
                # [------f+++t-----]
                if self.front < self.tail:
                    feat = self.feat_queue[self.front:self.tail]
                # [++t-----------f+]
                else:
                    feat = torch.cat([self.feat_queue[self.front:], self.feat_queue[:self.tail]], dim=0)

                self.front = (self.front + 2) % self.feat_queue.shape[0]
                self.tail = (self.tail + 2) % self.feat_queue.shape[0]

                # print(self.front, self.tail, feat.shape)

                self.att_feats.append(feat.permute(1, 0))
            
            att_feat = torch.stack(self.att_feats, dim=0) # [8, 44, 16]

            # discard old
            self.att_feats = self.att_feats[1:]
        else:
            # [------f+++t-----]
            if self.front < self.tail:
                feat = self.feat_queue[self.front:self.tail]
            # [++t-----------f+]
            else:
                feat = torch.cat([self.feat_queue[self.front:], self.feat_queue[:self.tail]], dim=0)

            self.front = (self.front + 2) % self.feat_queue.shape[0]
            self.tail = (self.tail + 2) % self.feat_queue.shape[0]

            att_feat = feat.permute(1, 0).unsqueeze(0)


        return att_feat

    def run_step(self):

        # get a frame of audio
        frame,type = self.get_audio_frame()
        self.frames.append(frame)
        # put to output
        self.output_queue.put((frame,type))
        # context not enough, do not run network.
        if len(self.frames) < self.stride_left_size + self.context_size + self.stride_right_size:
            return
        
        inputs = np.concatenate(self.frames) # [N * chunk]

        # discard the old part to save memory
        self.frames = self.frames[-(self.stride_left_size + self.stride_right_size):]

        #print(f'[INFO] frame_to_text... ')
        #t = time.time()
        logits, labels, text = self.__frame_to_text(inputs)
        #print(f'-------wav2vec time:{time.time()-t:.4f}s')
        feats = logits # better lips-sync than labels

        # record the feats efficiently.. (no concat, constant memory)
        start = self.feat_buffer_idx * self.context_size
        end = start + feats.shape[0]
        self.feat_queue[start:end] = feats
        self.feat_buffer_idx = (self.feat_buffer_idx + 1) % self.feat_buffer_size

        # very naive, just concat the text output.
        #if text != '':
        #    self.text = self.text + ' ' + text

        # will only run once at ternimation
        # if self.terminated:
        #     self.text += '\n[END]'
        #     print(self.text)
        #     if self.opt.asr_save_feats:
        #         print(f'[INFO] save all feats for training purpose... ')
        #         feats = torch.cat(self.all_feats, dim=0) # [N, C]
        #         # print('[INFO] before unfold', feats.shape)
        #         window_size = 16
        #         padding = window_size // 2
        #         feats = feats.view(-1, self.audio_dim).permute(1, 0).contiguous() # [C, M]
        #         feats = feats.view(1, self.audio_dim, -1, 1) # [1, C, M, 1]
        #         unfold_feats = F.unfold(feats, kernel_size=(window_size, 1), padding=(padding, 0), stride=(2, 1)) # [1, C * window_size, M / 2 + 1]
        #         unfold_feats = unfold_feats.view(self.audio_dim, window_size, -1).permute(2, 1, 0).contiguous() # [C, window_size, M / 2 + 1] --> [M / 2 + 1, window_size, C]
        #         # print('[INFO] after unfold', unfold_feats.shape)
        #         # save to a npy file
        #         if 'esperanto' in self.opt.asr_model:
        #             output_path = self.opt.asr_wav.replace('.wav', '_eo.npy')
        #         else:
        #             output_path = self.opt.asr_wav.replace('.wav', '.npy')
        #         np.save(output_path, unfold_feats.cpu().numpy())
        #         print(f"[INFO] saved logits to {output_path}")
    

        
    def __frame_to_text(self, frame):
        # frame: [N * 320], N = (context_size + 2 * stride_size)
        
        inputs = self.processor(frame, sampling_rate=self.sample_rate, return_tensors="pt", padding=True)
        
        with torch.no_grad():
            result = self.model(inputs.input_values.to(self.device))
            if 'hubert' in self.opt.asr_model:
                logits = result.last_hidden_state # [B=1, T=pts//320, hid=1024]
            else:
                logits = result.logits # [1, N - 1, 32]
        #print('logits.shape:',logits.shape)
        
        # cut off stride
        left = max(0, self.stride_left_size)
        right = min(logits.shape[1], logits.shape[1] - self.stride_right_size + 1) # +1 to make sure output is the same length as input.

        # do not cut right if terminated.
        # if self.terminated:
        #     right = logits.shape[1]

        logits = logits[:, left:right]

        # print(frame.shape, inputs.input_values.shape, logits.shape)
    
        #predicted_ids = torch.argmax(logits, dim=-1)
        #transcription = self.processor.batch_decode(predicted_ids)[0].lower()

        
        # for esperanto
        # labels = np.array(['ŭ', '»', 'c', 'ĵ', 'ñ', '”', '„', '“', 'ǔ', 'o', 'ĝ', 'm', 'k', 'd', 'a', 'ŝ', 'z', 'i', '«', '—', '‘', 'ĥ', 'f', 'y', 'h', 'j', '|', 'r', 'u', 'ĉ', 's', '–', 'fi', 'l', 'p', '’', 'g', 'v', 't', 'b', 'n', 'e', '[UNK]', '[PAD]'])

        # labels = np.array([' ', ' ', ' ', '-', '|', 'E', 'T', 'A', 'O', 'N', 'I', 'H', 'S', 'R', 'D', 'L', 'U', 'M', 'W', 'C', 'F', 'G', 'Y', 'P', 'B', 'V', 'K', "'", 'X', 'J', 'Q', 'Z'])
        # print(''.join(labels[predicted_ids[0].detach().cpu().long().numpy()]))
        # print(predicted_ids[0])
        # print(transcription)

        return logits[0], None,None #predicted_ids[0], transcription # [N,]
    

    def warm_up(self):       
        print(f'[INFO] warm up ASR live model, expected latency = {self.warm_up_steps / self.fps:.6f}s')
        t = time.time()
        #for _ in range(self.stride_left_size):
        #    self.frames.append(np.zeros(self.chunk, dtype=np.float32))
        for _ in range(self.warm_up_steps):
            self.run_step()
        #if torch.cuda.is_available():
        #    torch.cuda.synchronize()
        t = time.time() - t
        print(f'[INFO] warm-up done, actual latency = {t:.6f}s')

        #self.clear_queue()

    #####not used function#####################################
    '''
    def __init_queue(self):
        self.frames = []
        self.queue.queue.clear()
        self.output_queue.queue.clear()
        self.front = self.feat_buffer_size * self.context_size - 8 # fake padding
        self.tail = 8
        # attention window...
        self.att_feats = [torch.zeros(self.audio_dim, 16, dtype=torch.float32, device=self.device)] * 4
        
    def run(self):

        self.listen()

        while not self.terminated:
            self.run_step()

    def clear_queue(self):
        # clear the queue, to reduce potential latency...
        print(f'[INFO] clear queue')
        if self.mode == 'live':
            self.queue.queue.clear()
        if self.play:
            self.output_queue.queue.clear()

    def listen(self):
        # start
        if self.mode == 'live' and not self.listening:
            print(f'[INFO] starting read frame thread...')
            self.process_read_frame.start()
            self.listening = True
        
        if self.play and not self.playing:
            print(f'[INFO] starting play frame thread...')
            self.process_play_frame.start()
            self.playing = True

    def stop(self):

        self.exit_event.set()

        if self.play:
            self.output_stream.stop_stream()
            self.output_stream.close()
            if self.playing:
                self.process_play_frame.join()
                self.playing = False

        if self.mode == 'live':
            #self.input_stream.stop_stream() todo
            self.input_stream.close()
            if self.listening:
                self.process_read_frame.join()
                self.listening = False


    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_value, traceback):
        
        self.stop()

        if self.mode == 'live':
            # live mode: also print the result text.        
            self.text += '\n[END]'
            print(self.text)

def _read_frame(stream, exit_event, queue, chunk):
    while True:
        if exit_event.is_set():
            print(f'[INFO] read frame thread ends')
            break
        frame = stream.read(chunk, exception_on_overflow=False)
        frame = np.frombuffer(frame, dtype=np.int16).astype(np.float32) / 32767 # [chunk]
        queue.put(frame)

def _play_frame(stream, exit_event, queue, chunk):

    while True:
        if exit_event.is_set():
            print(f'[INFO] play frame thread ends')
            break
        frame = queue.get()
        frame = (frame * 32767).astype(np.int16).tobytes()
        stream.write(frame, chunk)
     #########################################################

if __name__ == '__main__':
    import argparse

    parser = argparse.ArgumentParser()
    parser.add_argument('--wav', type=str, default='')
    parser.add_argument('--play', action='store_true', help="play out the audio")
    
    # parser.add_argument('--model', type=str, default='cpierse/wav2vec2-large-xlsr-53-esperanto')
    # parser.add_argument('--model', type=str, default='facebook/wav2vec2-large-960h-lv60-self')
    parser.add_argument('--model', type=str, default='facebook/hubert-large-ls960-ft')

    parser.add_argument('--save_feats', action='store_true')
    # audio FPS
    parser.add_argument('--fps', type=int, default=50)
    # sliding window left-middle-right length.
    parser.add_argument('-l', type=int, default=10)
    parser.add_argument('-m', type=int, default=50)
    parser.add_argument('-r', type=int, default=10)
    
    opt = parser.parse_args()

    # fix
    opt.asr_wav = opt.wav
    opt.asr_play = opt.play
    opt.asr_model = opt.model
    opt.asr_save_feats = opt.save_feats

    if 'deepspeech' in opt.asr_model:
        raise ValueError("DeepSpeech features should not use this code to extract...")

    with ASR(opt) as asr:
        asr.run()
'''