app.py

import gradio as gr
import os
from huggingface_hub import InferenceClient
import random
from typing import Generator, Dict, List, Tuple, Optional

# Get token from environment variable
hf_token = os.environ.get("HF_TOKEN")
client = InferenceClient("HuggingFaceH4/zephyr-7b-beta", token=hf_token)

# Story genres with genre-specific example prompts
GENRE_EXAMPLES = {
    "fairy tale": [
        "I follow the shimmer of fairy dust into a hidden forest",
        "I meet a talking rabbit who claims to know a secret about the king's lost crown",
        "A tiny dragon appears at my window, asking for help to find its mother",
        "I step into a clearing where the trees whisper ancient riddles",
        "A friendly witch invites me into her cozy cottage, offering a warm cup of tea"
    ],
    "fantasy": [
        "I enter the ancient forest seeking the wizard's tower",
        "I approach the dragon cautiously with my shield raised",
        "I examine the mysterious runes carved into the stone altar",
        "I try to bargain with the elven council for safe passage"
    ],
    "sci-fi": [
        "I hack into the space station's mainframe",
        "I investigate the strange signal coming from the abandoned planet",
        "I negotiate with the alien ambassador about the peace treaty",
        "I try to repair my damaged spacecraft before oxygen runs out"
    ],
    "mystery": [
        "I examine the crime scene for overlooked evidence",
        "I question the nervous butler about the night of the murder",
        "I follow the suspicious figure through the foggy streets",
        "I check the victim's diary for hidden clues"
    ],
    "horror": [
        "I slowly open the creaking door to the basement",
        "I read the forbidden text while the candles flicker",
        "I hide under the bed as footsteps approach",
        "I investigate the strange noises coming from the attic"
    ],
    "western": [
        "I challenge the outlaw to a duel at high noon",
        "I track the bandits through the desert canyon",
        "I enter the saloon looking for information",
        "I defend the stagecoach from the approaching raiders"
    ],
    "cyberpunk": [
        "I jack into the corporate mainframe to steal data",
        "I negotiate with the street gang for cybernetic upgrades",
        "I hide in the neon-lit alleyway from corporate security",
        "I meet my mysterious client in the underground bar"
    ],
    "historical": [
        "I attend the royal ball hoping to meet the mysterious count",
        "I join the resistance against the occupying forces",
        "I navigate the dangerous politics of the royal court",
        "I set sail on a voyage to discover new lands"
    ],
    "post-apocalyptic": [
        "I scavenge the abandoned shopping mall for supplies",
        "I approach the fortified settlement seeking shelter",
        "I navigate through the radioactive zone using my old map",
        "I hide from the approaching group of raiders"
    ],
    "steampunk": [
        "I pilot my airship through the lightning storm",
        "I present my new invention to the Royal Academy",
        "I investigate the mysterious clockwork automaton",
        "I sneak aboard the emperor's armored train"
    ]
}

# Constants
MAX_HISTORY_LENGTH = 20
MEMORY_WINDOW = 5  # Reduced from 10 to limit context
MAX_TOKENS = 1024  # Reduced from 2048 for faster responses
TEMPERATURE = 0.7  # Slightly reduced for faster convergence
TOP_P = 0.95
MIN_RESPONSE_LENGTH = 100  # Reduced from 200 for quicker display

def get_examples_for_genre(genre):
    """Get example prompts specific to the selected genre"""
    return GENRE_EXAMPLES.get(genre, GENRE_EXAMPLES["fantasy"])

def get_enhanced_system_prompt(genre=None):
    """Generate a detailed system prompt with optional genre specification"""
    selected_genre = genre or "fantasy"
    system_message = f"""You are an interactive storyteller creating an immersive {selected_genre} choose-your-own-adventure story.
For each response you MUST:
1. Write 100-200 words describing the scene, using vivid sensory details
2. Always use second-person perspective ("you", "your") to maintain reader immersion
3. Include dialogue or your character's thoughts that reveal personality and motivations
4. Create a strong sense of atmosphere appropriate for {selected_genre}
5. End EVERY response with exactly three numbered choices like this:

1. [Complete sentence in second-person starting with a verb (e.g., "You decide to..."/"You attempt to...")]
2. [Complete sentence in second-person starting with a verb (e.g., "You sneak towards..."/"You call out to...")]
3. [Complete sentence in second-person starting with a verb (e.g., "You examine..."/"You reach for...")]

IMPORTANT:
- Always maintain second-person perspective throughout the narrative
- Always end with exactly three numbered choices
- Never skip the choices or respond with just narrative
- Each choice must start with "You" followed by a verb
- Format choices exactly as shown above with numbers 1-3

Keep the story cohesive by referencing previous events and choices."""
    return system_message

def respond(
    message: str, 
    chat_history: List[Tuple[str, str]], 
    genre: Optional[str] = None,
    use_full_memory: bool = True
) -> List[Tuple[str, str]]:
    """Generate a response based on the current message and conversation history."""
    if not message.strip():
        return chat_history

    try:
        # Format messages for API - always start with system prompt
        api_messages = [{"role": "system", "content": get_enhanced_system_prompt(genre)}]
        
        # Add chat history in correct format
        if chat_history and use_full_memory:
            for user_msg, bot_msg in chat_history[-MEMORY_WINDOW:]:
                # Only add completed exchanges (where both user and bot messages exist)
                if user_msg and bot_msg:
                    api_messages.append({"role": "user", "content": str(user_msg)})
                    api_messages.append({"role": "assistant", "content": str(bot_msg)})
        
        # Add current message
        api_messages.append({"role": "user", "content": str(message)})

        # Make API call with properly formatted messages
        response = client.chat_completion(
            model="HuggingFaceH4/zephyr-7b-beta",  # Explicitly specify model
            messages=api_messages,
            max_tokens=MAX_TOKENS,
            temperature=TEMPERATURE,
            top_p=TOP_P
        )
        
        # Extract bot message and append to history
        bot_message = response.choices[0].message.content
        new_history = list(chat_history)
        new_history.append((str(message), str(bot_message)))
        return new_history
                        
    except Exception as e:
        # Return existing history plus error message
        return chat_history + [(str(message), f"Story magic temporarily interrupted. Please try again. (Error: {str(e)})")]

def save_story(chat_history):
    """Convert chat history to markdown for download"""
    if not chat_history:
        return "No story to save yet!"
    
    story_text = "# My Interactive Adventure\n\n"
    for user_msg, bot_msg in chat_history:
        story_text += f"**Player:** {user_msg}\n\n"
        story_text += f"**Story:** {bot_msg}\n\n---\n\n"
    
    return story_text

# Define the Gradio interface
with gr.Blocks(theme=gr.themes.Soft()) as demo:
    gr.Markdown("# 🔮 Interactive Story Time")
    with gr.Row():
        status_message = gr.Markdown("Ready to begin your adventure...", visible=True)
    gr.Markdown("Create a completely unique literary world, one choice at a time. Dare to explore the unknown.")
    
    with gr.Row():
        with gr.Column(scale=3):
            # Chat window + user input
            chatbot = gr.Chatbot(
                height=500,
                bubble_full_width=True,
                show_copy_button=True,
                avatar_images=(None, "🧙"),
                type="messages",
                container=True,
                scale=1,
                min_width=800,
                value=[]
            )
            msg = gr.Textbox(
                placeholder="Describe what you want to do next in the story...",
                container=False,
                scale=4,
            )
            
            with gr.Row():
                submit = gr.Button("Continue Story", variant="primary")
                clear = gr.Button("Start New Adventure")
                
        with gr.Column(scale=1):
            gr.Markdown("## Adventure Settings")
            genre = gr.Dropdown(
                choices=list(GENRE_EXAMPLES.keys()),
                label="Story Genre",
                info="Choose the theme of your next adventure",
                value="fantasy"
            )
            full_memory = gr.Checkbox(
                label="Full Story Memory",
                value=True,
                info="When enabled, the AI tries to remember the entire story. If disabled, only the last few exchanges are used."
            )
            
            gr.Markdown("## Story Starters")
            
            # Create four placeholder buttons for story starters
            starter_btn1 = gr.Button("Starter 1")
            starter_btn2 = gr.Button("Starter 2")
            starter_btn3 = gr.Button("Starter 3")
            starter_btn4 = gr.Button("Starter 4")
            starter_buttons = [starter_btn1, starter_btn2, starter_btn3, starter_btn4]

            def update_starter_buttons(selected_genre):
                """Update starter buttons with examples for the selected genre."""
                examples = get_examples_for_genre(selected_genre)
                results = []
                for i in range(4):
                    if i < len(examples):
                        results.append(examples[i])
                    else:
                        results.append("")
                return tuple(results)

            # Initialize with default genre
            initial_button_data = update_starter_buttons("fantasy")

            # Connect each starter button
            for starter_button in starter_buttons:
                # First, update chatbot with starter message
                starter_button.click(
                    fn=lambda x: [(str(x), "")],
                    inputs=[starter_button],
                    outputs=[chatbot],
                    queue=False
                ).success(
                    # Then process the message with respond function
                    fn=respond,
                    inputs=[
                        starter_button,
                        chatbot,
                        genre,
                        full_memory
                    ],
                    outputs=chatbot,
                    queue=True
                )

            # Update buttons when genre changes
            genre.change(
                fn=update_starter_buttons,
                inputs=[genre],
                outputs=starter_buttons
            )

    # Handler for user input
    msg.submit(respond, [msg, chatbot, genre, full_memory], [chatbot])
    submit.click(respond, [msg, chatbot, genre, full_memory], [chatbot])
    
    # Clear the chatbot for a new adventure
    clear.click(lambda: [], None, chatbot, queue=False)
    clear.click(lambda: "", None, msg, queue=False)
    
    # "Download My Story" row
    with gr.Row():
        save_btn = gr.Button("Download My Story", variant="secondary")
        story_output = gr.Markdown(visible=False)
    
    save_btn.click(save_story, inputs=[chatbot], outputs=[story_output])
    save_btn.click(
        fn=lambda: True,
        inputs=None,
        outputs=story_output,
        js="() => {document.getElementById('story_output').scrollIntoView();}",
        queue=False
    )

    # Load initial button data
    demo.load(
        fn=lambda: initial_button_data,
        outputs=starter_buttons,
        queue=False
    )

# Run the app
if __name__ == "__main__":
    demo.launch(server_name="0.0.0.0", server_port=7860)