from transformers import AutoTokenizer
import re
import torch

def model_fn(model_dir):

    # Load Tokenizer, Model and Default template
    tokenizer = AutoTokenizer.from_pretrained(model_dir)
    model = torch.load(f"{model_dir}/torch_model.pt")
    template = open(f"{model_dir}/default_template.txt","r").read()
    return model, tokenizer, template

def predict_fn(data, load_list):

    # Get model, tokenzier and template from the model_fn
    model, tokenizer, template = load_list

    # Parse the input request into correct format to generate model input
    request_inputs = data.pop("inputs", data)
    messages = request_inputs["messages"]
    char_name = request_inputs["char_name"]
    user_name = request_inputs["user_name"]
    chats_curled = request_inputs["chats_curled"]
    user_input = [
        "{name}: {message}".format(
            name = char_name if (id["role"] == "AI") else user_name,
            message = id["message"].strip()
        ) for id in messages
    ]

    # Tokenize the model input
    while True:
        prompt = template.format(char_name = char_name, user_name = user_name, user_input = "\n".join([user_input]))
        input_ids = tokenizer(prompt + f"\n{char_name}:", return_tensors = "pt").to("cuda")
        if input_ids.input_ids.size(1) > 2048:
            chats_curled += 1
            user_input = user_input[chats_curled*2:]
        else: break

    encoded_output = model.generate(
        input_ids["input_ids"],
        max_new_tokens = 50,
        temperature = 0.5,
        top_p = 0.9,
        top_k = 0,
        repetition_penalty = 1.1,
        pad_token_id = 50256,
        num_return_sequences = 1
    )
    decoded_output = tokenizer.decode(encoded_output[0], skip_special_tokens=True).replace(prompt,"")

    # Parse the decoded output to the expected response
    decoded_output = decoded_output.split(f"{char_name}:", 1)[1].split(f"{user_name}:",1)[0].strip()
    parsed_result = re.sub('\*.*?\*', '', decoded_output).strip()
    if len(parsed_result) != 0: decoded_output = parsed_result
    decoded_output = " ".join(decoded_output.replace("*","").split())
    try:
        parsed_result = decoded_output[:[m.start() for m in re.finditer(r'[.!?]', decoded_output)][-1]+1]
        if len(parsed_result) != 0: decoded_output = parsed_result
    except Exception: pass
    return {
        "role": "AI",
        "message": decoded_output,
        "chats_curled": chats_curled
    }