import streamlit as st
import time

from better_transformer import *

def main():

    # Enable CUDA if available and load in tokenizer
    device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
    tokenizer, EMPTY_TOKENS = load_tokenizer(device)

    st.title("TinyStories Transformer Demo 🤖")

    st.subheader("Data and Training")
    
    st.markdown("""We used the dataset from Microsoft Research's [TinyStories Paper](https://arxiv.org/pdf/2305.07759.pdf) (Eldan and Li), 
    which consists of 2.1 million synthetic short children's stories generated by GPT-4, to train a PyTorch Transformer LLM.""")
    st.markdown("""Our model uses EleutherAI's [gpt-neo-1.3B tokenizer](https://huggingface.co/EleutherAI/gpt-neo-1.3B) (vocab size 50,257) and consists of 8 transformer blocks, 
    16 attention heads, and an embedding dimension of 768, for a total of ~56M non-embedding parameters. The model was trained overnight on 8 H100 GPUs, achieving a lower cross-entropy 
    validation loss than any of the models in the TinyStories paper (likely due to a larger vocab size).""")
    st.markdown("""Despite the simple themes and limited vocabulary present in the training data, the model is
    quite effective at generating new short stories. **Try it out below!**""")

    st.subheader("How Do I Prompt?")
    st.markdown(
        """
        Instead of generating a new story from scratch, you can "prompt" the model by writing the first few sentences of a story, and let it finish from there. It can even jump in mid-sentence!

        The model can struggle with some prompts, especially those outside of its limited domain. If a response isn't satisfactory, try repeating the generation, or make the following modifications:
        """
    )
    st.markdown(
        """
        - **Use simple vocabulary and syntax** - words, structures, and themes you'd see in a children's story.
        - Use common first names only - the model can struggle with longer or uncommon names.

        `SAMPLE PROMPT: Once upon a time, there was a little girl named Lily. She loved to play at the park with her friend Timmy. One day, Lily and Timmy`
        """
    )
        
    st.subheader("Let's make some stories! 📖")

    # Input from user
    user_input = st.text_input("Enter your prompt:", placeholder="Write a prompt to make a story of your own, or leave it empty for a random story!").strip()

    ## Default values for advanced settings
    user_seed = None # Remove if we're not rigging the "random" demo
    generation_method = "top-k"
    specified_k = 5
    specified_nucleus = 0.5
    specified_temperature = 0.4
    max_tokens = 1000

    if st.checkbox("Show Advanced Settings"):
        user_seed = st.number_input("Randomness Seed:", value = None, step = 1, placeholder="Use to replicate response", min_value = 1)
        generation_method = st.selectbox("Method of Generation:", ("top-k", "nucleus", "temperature", "multinomial", "greedy"), index = 0).strip()

        if generation_method == "top-k":
            specified_k = st.number_input("Value for k:", value = 5, step = 1)

        if generation_method == "nucleus":
            specified_nucleus = st.number_input("Nucleus Cutoff:", value = 0.5, step = 0.05, min_value = 0.0, max_value = 1.0)

        if generation_method == "temperature":
            specified_temperature = st.number_input("Value for temperature:", value = 0.4, step = 0.05, min_value = 0.0, max_value = 1.0)

        max_tokens = st.slider('Max Tokens Generated:', 50, 1000, 1000)





    # model_version = st.radio("Which model would you like to use?", ["smoll", "beeg"])
    # small_model = load_casey_model(tokenizer, device)
    model = load_big_model(tokenizer, device)
    model.to('cuda')
    model.cuda()


    if st.button('Write my story!'):
        placeholder = st.empty()
        # if model_version == 'smoll':
        #     model = load_casey_model(tokenizer, device)
        # elif model_version == 'beeg':
        #     model = load_big_model(tokenizer, device)
        # with placeholder.container():
        #     st.write("Model Loaded! Preparing to Generate...")


        

        with st.spinner(""):
            result = generate(model, tokenizer, device, method=generation_method, k=specified_k, 
                            p_nucleus=specified_nucleus, temp=specified_temperature, max_new_tokens=max_tokens, 
                            cond=user_input, deterministic=user_seed)
            st.markdown("\n")
            st.markdown("\n")
            st.markdown("\n")
            st.markdown("\n")

        streamed_input = ""
        for word in user_input.split(' '):
            streamed_input += word
            with placeholder.container():
                st.markdown(f"**{streamed_input}**")
            streamed_input += " "
            time.sleep(0.1)

        if user_input != "": ##conditional
            result = result[len(user_input) + 3 :]
            streamed_result = f"**{streamed_input[:-1]}**"
            time.sleep(1)
        else: ##unconditional
            streamed_result = ""


        for word in result.split(' '):
            streamed_result += word + ' '
            with placeholder.container():
                st.markdown(f"{streamed_result}")
            time.sleep(0.1)
        if st.button('Clear Output'):
            placeholder = st.empty()

    st.markdown('####')
    st.caption('UCLA DSU Project Fall 2023: Daniel Mendelevitch, Terry Ming, Casey Tattersall, Sean Tjoa')
    st.caption(r'Data Attribution: Tinystories (License: CDLA-Sharing-1.0)  https://arxiv.org/abs/2305.07759')


if __name__ == "__main__":
    main()