import gradio as gr
import torch
import soundfile as sf
from snac import SNAC
from transformers import AutoTokenizer, AutoModelForCausalLM

device = torch.device("cuda" if torch.cuda.is_available() else "cpu")

def find_last_instance_of_separator(lst, element=50258):
    reversed_list = lst[::-1]
    try:
        reversed_index = reversed_list.index(element)
        return len(lst) - 1 - reversed_index
    except ValueError:
        raise ValueError

def reconstruct_tensors(flattened_output):
    def count_elements_between_hashes(lst):
        try:
            first_index = lst.index(50258)
            second_index = lst.index(50258, first_index + 1)
            return second_index - first_index - 1
        except ValueError:
            return "List does not contain two '#' symbols"

    def remove_elements_before_hash(flattened_list):
        try:
            first_hash_index = flattened_list.index(50258)
            return flattened_list[first_hash_index:]
        except ValueError:
            return "List does not contain the symbol '#'"

    def list_to_torch_tensor(tensor1):
        tensor = torch.tensor(tensor1)
        tensor = tensor.unsqueeze(0)
        return tensor

    flattened_output = remove_elements_before_hash(flattened_output)
    last_index = find_last_instance_of_separator(flattened_output)
    flattened_output = flattened_output[:last_index]

    codes = []
    tensor1 = []
    tensor2 = []
    tensor3 = []
    tensor4 = []

    n_tensors = count_elements_between_hashes(flattened_output)
    if n_tensors == 7:
        for i in range(0, len(flattened_output), 8):
            tensor1.append(flattened_output[i+1])
            tensor2.append(flattened_output[i+2])
            tensor3.append(flattened_output[i+3])
            tensor3.append(flattened_output[i+4])
            tensor2.append(flattened_output[i+5])
            tensor3.append(flattened_output[i+6])
            tensor3.append(flattened_output[i+7])
            codes = [list_to_torch_tensor(tensor1).to(device), list_to_torch_tensor(tensor2).to(device), list_to_torch_tensor(tensor3).to(device)]

    if n_tensors == 15:
        for i in range(0, len(flattened_output), 16):
            tensor1.append(flattened_output[i+1])
            tensor2.append(flattened_output[i+2])
            tensor3.append(flattened_output[i+3])
            tensor4.append(flattened_output[i+4])
            tensor4.append(flattened_output[i+5])
            tensor3.append(flattened_output[i+6])
            tensor4.append(flattened_output[i+7])
            tensor4.append(flattened_output[i+8])
            tensor2.append(flattened_output[i+9])
            tensor3.append(flattened_output[i+10])
            tensor4.append(flattened_output[i+11])
            tensor4.append(flattened_output[i+12])
            tensor3.append(flattened_output[i+13])
            tensor4.append(flattened_output[i+14])
            tensor4.append(flattened_output[i+15])
            codes = [list_to_torch_tensor(tensor1).to(device), list_to_torch_tensor(tensor2).to(device), list_to_torch_tensor(tensor3).to(device), list_to_torch_tensor(tensor4).to(device)]

    return codes

def load_model():
    tokenizer = AutoTokenizer.from_pretrained("Lwasinam/voicera-jenny-finetune")
    model = AutoModelForCausalLM.from_pretrained("Lwasinam/voicera-jenny-finetune").to(device)
    snac_model = SNAC.from_pretrained("hubertsiuzdak/snac_24khz").eval()
    return model, tokenizer, snac_model

def SpeechDecoder(codes, snac_model):
    codes = codes.squeeze(0).tolist()
    reconstructed_codes = reconstruct_tensors(codes)
    audio_hat = snac_model.to(device).decode(reconstructed_codes)
    audio_path = "reconstructed_audio.wav"
    sf.write(audio_path, audio_hat.squeeze().cpu().detach().numpy(), 24000)
    return audio_path

def generate_audio(text, tokenizer, model, snac_model):
    output_codes = []
    with torch.no_grad():
        input_text = text
        input_ids = tokenizer(input_text, return_tensors='pt').to(device)
        output_codes = model.generate(input_ids['input_ids'], attention_mask=input_ids['attention_mask'], max_length=1024,
                                      num_beams=5, top_p=0.95, temperature=0.8, do_sample=True, repetition_penalty=2.0)
        audio_path = SpeechDecoder(output_codes, snac_model)
    return audio_path

def main(text):
    model, tokenizer, snac_model = load_model()
    audio_path = generate_audio(text, tokenizer, model, snac_model)
    return audio_path

# Define the Gradio interface
iface = gr.Interface(
    fn=main,
    inputs='textbox',
    outputs="audio",
    title="Voicera TTS",
    description="Generate speech from text using Voicera TTS model."
)

if __name__ == "__main__":
    iface.launch()