import gradio as gr
import torch
from mingru_lm import MinGRU_LM

# Load the model
model = MinGRU_LM(dim=512, num_tokens=256, num_layers=6)
pt_model = "best_model.pt"
checkpoint = torch.load(pt_model, map_location=torch.device('cpu'))
model.load_state_dict(checkpoint['model_state_dict'])

# Move model to GPU if available
device = 'cuda' if torch.cuda.is_available() else 'cpu'
model = model.to(device)

def decode_tokens(tokens):
    return ''.join([chr(token) for token in tokens if token >= 32 and token < 256])  # ASCII-safe decoding

def tokenize_text(text):
    return [ord(char) for char in text if ord(char) < 256]  # ASCII-safe tokenization

def generate_text(start_text, max_length, temperature):
    model.eval()
    
    tokens = tokenize_text(start_text)
    input_tensor = torch.tensor(tokens, dtype=torch.long).unsqueeze(0).to(device)  # Ensure long tensor
    
    generated_tokens = tokens.copy()

    # Use a generator to yield tokens one by one
    for _ in range(max_length):
        with torch.no_grad():
            logits = model(input_tensor, labels=None)[1]  # Get logits directly
            
            last_token_logits = logits[0, -1, :] / temperature
            probs = torch.softmax(last_token_logits, dim=-1)
            
            # Sample the next token
            next_token = torch.multinomial(probs, num_samples=1).item()
            
            # Only append valid tokens
            if next_token < 256:  
                generated_tokens.append(next_token)
                input_tensor = torch.cat([input_tensor, torch.tensor([[next_token]], device=device)], dim=1)
                
                yield decode_tokens(generated_tokens)
            else:
                continue  # Skip tokens outside ASCII range
        
    yield decode_tokens(generated_tokens)

def wrapper_generate_text(start_text, max_length, temperature):
    async_gen = generate_text(start_text, max_length, temperature)
    
    for output in async_gen:
        yield output

# Gradio interface
with gr.Blocks() as iface:
    gr.Markdown("The MinGRU model is a simplified version of the traditional Gated Recurrent Unit (GRU), designed to reduce complexity and improve efficiency,Trained on the [tiny-stories](https://huggingface.co/datasets/roneneldan/TinyStories?row=19)")
    gr.Markdown("To Learn more visit this [github](https://github.com/dame-cell/MinGru/tree/main)")
    with gr.Row():
        textbox = gr.Textbox(lines=3, label="Enter your prompt", value="Once upon a time")
        max_length = gr.Slider(minimum=10, maximum=500, value=200, step=1, label="Max Length")
        temperature = gr.Slider(minimum=0.1, maximum=2.0, value=0.7, step=0.1, label="Temperature")
    
    output_textbox = gr.Textbox(lines=10, label="Generated Text")
    
    btn = gr.Button("Generate Text")
    
    btn.click(
        wrapper_generate_text, 
        inputs=[textbox, max_length, temperature],
        outputs=output_textbox
    )

iface.launch(show_api=False, server_name="0.0.0.0")