app.py

# app.py
import os
import gradio as gr
from anthropic import Anthropic
from datetime import datetime, timedelta
from collections import deque

# Initialize Anthropic client - will use the secret key from HuggingFace
anthropic = Anthropic(
    api_key=os.environ.get('ANTHROPIC_API_KEY')
)

# Request tracking
MAX_REQUESTS_PER_DAY = 25  # Conservative limit to start
request_history = deque(maxlen=1000)

def check_api_key():
    """Verify API key is configured"""
    if not os.environ.get('ANTHROPIC_API_KEY'):
        raise ValueError("Anthropic API key not found. Please configure it in HuggingFace Spaces settings.")

def check_rate_limit():
    """Check if we're within rate limits"""
    now = datetime.now()
    # Remove requests older than 24 hours
    while request_history and (now - request_history[0]) > timedelta(days=1):
        request_history.popleft()
    return len(request_history) < MAX_REQUESTS_PER_DAY

def clean_latex(text):
    """Simple LaTeX cleaning"""
    text = text.replace('\n', '\n\n')
    return text

def generate_test(subject):
    """Generate a math test with error handling and rate limiting"""
    try:
        # Check API key
        check_api_key()
        
        # Check rate limit
        if not check_rate_limit():
            return "Daily request limit reached. Please try again tomorrow."
        
        # Record request
        request_history.append(datetime.now())
        
        system_prompt = """You will write math exam questions. Follow these requirements EXACTLY:
        1. Write exactly 3 challenging university-level questions
        2. For LaTeX math formatting:
           - Use $ for simple inline math
           - For equations and solution steps, use $$ on separate lines
           - For multi-step solutions, put each step on its own line in $$ $$
           - DO NOT use \\begin{aligned} or any other environments
        3. Number each question as 1), 2), 3)
        4. Include solutions after each question
        5. Keep formatting simple and clear"""
        
        message = anthropic.messages.create(
            model="claude-3-opus-20240229",
            max_tokens=1500,
            temperature=0.7,
            messages=[{
                "role": "user",
                "content": f"{system_prompt}\n\nWrite an exam for {subject}."
            }]
        )
        
        # Extract usage information
        input_tokens = message.usage.input_tokens
        output_tokens = message.usage.output_tokens
        input_cost = (input_tokens / 1000) * 0.015
        output_cost = (output_tokens / 1000) * 0.075
        total_cost = input_cost + output_cost
        
        usage_stats = f"""
        \n---\nUsage Statistics:
        • Input Tokens: {input_tokens:,}
        • Output Tokens: {output_tokens:,}
        • Total Tokens: {input_tokens + output_tokens:,}
        
        Cost Breakdown:
        • Input Cost: ${input_cost:.4f}
        • Output Cost: ${output_cost:.4f}
        • Total Cost: ${total_cost:.4f}
        """
        
        if hasattr(message, 'content') and len(message.content) > 0:
            response_text = message.content[0].text
            formatted_response = clean_latex(response_text) + usage_stats
            return formatted_response
        else:
            return "Error: No content in response"
            
    except ValueError as e:
        return f"Configuration Error: {str(e)}"
    except Exception as e:
        return f"Error: {str(e)}"

# Subject choices
subjects = [
    "Single Variable Calculus",
    "Multivariable Calculus", 
    "Linear Algebra",
    "Differential Equations",
    "Real Analysis",
    "Complex Analysis",
    "Abstract Algebra",
    "Probability Theory",
    "Numerical Analysis",
    "Topology"
]

# Create Gradio interface
interface = gr.Interface(
    fn=generate_test,
    inputs=gr.Dropdown(
        choices=subjects,
        label="Select Mathematics Subject",
        info="Choose a subject for the exam questions"
    ),
    outputs=gr.Markdown(
        label="Generated Test",
        latex_delimiters=[
            {"left": "$$", "right": "$$", "display": True"},
            {"left": "$", "right": "$", "display": False}
        ]
    ),
    title="Advanced Mathematics Test Generator",
    description="""Generates university-level mathematics exam questions with solutions using Claude 3 Opus.
    Limited to 25 requests per day. Please use responsibly.""",
    theme="default",
    allow_flagging="never"
)

# Launch the interface
if __name__ == "__main__":
    interface.launch()