import gradio as gr
from huggingface_hub import InferenceClient
from datasets import load_dataset
import random
import re

# Global datasets - load lazily
math_samples = None

def load_datasets_lazy():
    """Load datasets only when needed - prevents startup crashes"""
    global math_samples
    if math_samples is not None:
        return math_samples
    
    print("🔄 Loading datasets...")
    try:
        gsm8k = load_dataset("openai/gsm8k", "main", streaming=True)
        samples = []
        for i, item in enumerate(gsm8k["train"]):
            samples.append(item["question"])
            if i >= 50:
                break
        print(f"✅ Loaded {len(samples)} GSM8K samples")
        math_samples = samples
        return samples
    except Exception as e:
        print(f"⚠️ Dataset error: {e}, using fallback")
        math_samples = [
            "What is the derivative of f(x) = 3x² + 2x - 1?",
            "A triangle has sides of length 5, 12, and 13. What is its area?",
            "If log₂(x) + log₂(x+6) = 4, find the value of x.",
            "Find the limit: lim(x->0) (sin(x)/x)",
            "Solve the system: x + 2y = 7, 3x - y = 4"
        ]
        return math_samples

def create_math_system_message():
    """Specialized system prompt for mathematics with LaTeX"""
    return """You are Mathetics AI, an advanced mathematics tutor and problem solver.

🧮 **Your Expertise:**
- Step-by-step problem solving with clear explanations
- Multiple solution approaches when applicable
- Proper mathematical notation and terminology using LaTeX
- Verification of answers through different methods

📐 **Problem Domains:**
- Arithmetic, Algebra, and Number Theory
- Geometry, Trigonometry, and Coordinate Geometry
- Calculus (Limits, Derivatives, Integrals)
- Statistics, Probability, and Data Analysis
- Competition Mathematics (AMC, AIME level)

💡 **Teaching Style:**
1. **Understand the Problem** - Identify what's being asked
2. **Plan the Solution** - Choose the appropriate method
3. **Execute Step-by-Step** - Show all work clearly with LaTeX formatting
4. **Verify the Answer** - Check if the result makes sense
5. **Alternative Methods** - Mention other possible approaches

**LaTeX Guidelines:**
- Use $...$ for inline math: $x^2 + y^2 = z^2$
- Use $$...$$ for display math
- Box final answers: \boxed{answer}
- Fractions: \frac{numerator}{denominator}
- Limits: \lim_{x \to 0}
- Derivatives: \frac{d}{dx} or f'(x)

Always be precise, educational, and encourage mathematical thinking."""

def render_latex(text):
    """Enhanced LaTeX rendering - fixes raw code output"""
    if not text or len(text) < 5:
        return text
    
    try:
        # Fix common LaTeX patterns from Qwen
        text = re.sub(r'(?<!\\)\$([^\$]+)\$(?!\$)', r'$\1$', text)
        text = re.sub(r'\$\$([^\$]+)\$\$', r'$$\1$$', text)
        text = re.sub(r'\\\[([^\\]+)\\\]', r'$$\1$$', text)
        text = re.sub(r'\\\(([^\\]+)\\\)', r'$\1$', text)
        
        # Fix escaped LaTeX commands
        text = re.sub(r'\\(lim|frac|sqrt|int|sum|prod|partial|nabla|infty|to|le|ge|neq|approx|cdot|times|div|deg|prime|log|ln|sin|cos|tan|cot|sec|csc|arcsin|arccos|arctan|sinh|cosh)', r'\1', text)
        
        # Ensure boxed answers render
        text = re.sub(r'\\boxed\{([^}]+)\}', r'$$\boxed{\1}$$', text)
        text = re.sub(r'\\frac\{([^}]+)\}\{([^}]+)\}', r'$\frac{\1}{\2}$', text)
        
        # Clean up extra spaces
        text = re.sub(r'\s*([\$\\])\s*', r'\1', text)
        
    except Exception as e:
        print(f"⚠️ LaTeX formatting error: {e}")
    
    return text

def respond(message, history, system_message, max_tokens, temperature, top_p):
    """Enhanced response with proper LaTeX streaming"""
    yield "🤔 Thinking step-by-step..."
    
    client = InferenceClient(model="Qwen/Qwen2.5-Math-7B-Instruct")
    
    messages = []
    if system_message:
        messages.append({"role": "system", "content": system_message})
    
    # Convert history to proper format
    for user_msg, assistant_msg in history:
        if user_msg:
            messages.append({"role": "user", "content": user_msg})
        if assistant_msg:
            messages.append({"role": "assistant", "content": assistant_msg})
    
    messages.append({"role": "user", "content": message})
    
    response = ""
    max_tokens = max(max_tokens, 1536)
    
    try:
        for message_chunk in client.chat_completion(
            messages,
            max_tokens=max_tokens,
            stream=True,
            temperature=temperature,
            top_p=top_p,
            timeout=60
        ):
            choices = message_chunk.choices
            if len(choices) and choices[0].delta.content:
                token = choices[0].delta.content
                response += token
                
                if len(response) % 50 == 0 or token.strip() in ['.', '!', '?', '\n']:
                    formatted = render_latex(response)
                    yield formatted
                else:
                    yield response
                    
        final_formatted = render_latex(response.strip())
        yield final_formatted
            
    except Exception as e:
        error_msg = f"❌ **Error**: {str(e)[:100]}...\n\n💡 Try a simpler problem or wait a moment."
        yield error_msg

def get_random_sample():
    """Get a random sample problem - loads datasets if needed"""
    global math_samples
    if math_samples is None:
        math_samples = load_datasets_lazy()
    if math_samples:
        return random.choice(math_samples)
    return "Solve for x: 2x² + 5x - 3 = 0"

def insert_sample_to_chat(difficulty):
    """Insert random sample into chat input"""
    sample = get_random_sample()
    return sample

def show_help():
    return """**🧮 Math Help Tips:**

1. **Be Specific**: "Find the derivative of x² + 3x" instead of "help with calculus"
2. **Request Steps**: "Show me step-by-step how to solve..."
3. **Ask for Verification**: "Check if my answer x=5 is correct"
4. **Alternative Methods**: "What's another way to solve this integral?"
5. **Use Clear Notation**: "lim(x->0)" for limits

**Pro Tip**: Crank tokens to 1500+ for competition problems!"""

# CLASSIC Chatbot interface (Gradio 3.x compatible)
def chat_response(message, history):
    """Main chat function - compatible with all Gradio versions"""
    bot_response = ""
    for response in respond(
        message, 
        history, 
        create_math_system_message(), 
        1024,  # Default tokens
        0.3,    # Default temperature
        0.85    # Default top_p
    ):
        bot_response = response
        history.append([message, bot_response])
        yield history, ""
    
    return history, ""

# Build the interface
with gr.Blocks(
    title="🧮 Mathetics AI", 
    theme=gr.themes.Soft(),
    css="""
    /* Enhanced math rendering */
    .markdown-body { font-family: 'Times New Roman', Georgia, serif; line-height: 1.6; }
    .katex { font-size: 1.1em !important; color: #2c3e50; }
    .katex-display { font-size: 1.3em !important; text-align: center; margin: 1em 0; padding: 10px; background: #f8f9fa; border-radius: 8px; }
    
    /* Chat styling */
    .message { margin: 10px 0; padding: 12px; border-radius: 8px; }
    .user { background: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 100%); border-left: 4px solid #2196f3; }
    .assistant { background: linear-gradient(135deg, #f5f5f5 0%, #eeeeee 100%); border-left: 4px solid #4caf50; }
    
    /* Sidebar */
    .difficulty-selector { background: linear-gradient(135deg, #fff3e0 0%, #ffe0b2 100%); padding: 15px; border-radius: 10px; margin: 10px 0; border: 1px solid #ffcc80; }
    
    /* Responsive */
    @media (max-width: 768px) { .katex { font-size: 1em !important; } .katex-display { font-size: 1.1em !important; } }
    """
) as demo:
    
    gr.Markdown("""
    # 🧮 **Mathetics AI** - Advanced Mathematics Solver
    
    **Your Personal AI Math Tutor** | Step-by-step solutions with beautiful LaTeX rendering
    
    ---
    """)
    
    # Main chat interface
    chatbot = gr.Chatbot(
        height=500,
        show_label=False,
        avatar_images=("🧑‍🎓", "🤖"),
        bubble_full_width=False
    )
    
    with gr.Row():
        msg = gr.Textbox(
            placeholder="Ask: 'Find the derivative of 3x² + 2x - 1'",
            scale=4,
            show_label=False,
            lines=2
        )
        submit_btn = gr.Button("🚀 Solve", variant="primary", scale=1)
    
    # Controls
    with gr.Row():
        with gr.Column(scale=2):
            token_slider = gr.Slider(256, 2048, value=1024, step=128, label="📝 Max Tokens")
            temp_slider = gr.Slider(0.1, 1.0, value=0.3, step=0.1, label="🎯 Temperature")
            
        with gr.Column(scale=1):
            difficulty_preset = gr.Dropdown(
                choices=["Elementary", "High School", "College", "Competition"],
                value="High School",
                label="🎯 Difficulty",
                elem_classes=["difficulty-selector"]
            )
            sample_btn = gr.Button("🎲 Random Problem", variant="secondary")
            help_btn = gr.Button("❓ Help", variant="secondary")
    
    # Examples
    gr.Examples(
        examples=[
            ["Find the derivative of f(x) = 3x² + 2x - 1"],
            ["A triangle has sides 5, 12, and 13. What is its area?"],
            ["Solve: lim(x->0) sin(x)/x"],
            ["What is ∫(2x³ - 5x + 3) dx?"],
            ["Solve the system: x + 2y = 7, 3x - y = 4"]
        ],
        inputs=msg,
        label="💡 Quick Examples"
    )
    
    # Event handlers
    def submit_message(message, history):
        return chat_response(message, history)
    
    def clear_chat():
        return [], ""
    
    msg.submit(submit_message, [msg, chatbot], [msg, chatbot])
    submit_btn.click(submit_message, [msg, chatbot], [msg, chatbot])
    
    sample_btn.click(
        insert_sample_to_chat,
        inputs=[difficulty_preset],
        outputs=msg
    )
    
    help_btn.click(
        show_help,
        outputs=gr.Markdown(visible=True, label="Help")
    )
    
    # Clear button
    gr.Button("🗑️ Clear Chat", variant="secondary").click(
        clear_chat,
        outputs=[chatbot, msg]
    )
    
    gr.Markdown("""
    ---
    **🔧 Tech:** Qwen2.5-Math-7B • LaTeX rendering • Streaming responses
    **💡 Tip:** Use "lim(x->0)" for limits, crank tokens for complex problems
    """)

if __name__ == "__main__":
    demo.launch()