"""
Study Ocean AI Mentor — Gradio Web Interface

A beautiful, student-friendly chat interface for the RAG-based
doubt-solving mentor. Built with Gradio for easy deployment.
"""

import gradio as gr
from rag_chain import get_chain, ask_question

# ─── Custom CSS for Premium Look ────────────────────────────
CUSTOM_CSS = """
/* Global */
.gradio-container {
    max-width: 900px !important;
    margin: auto !important;
    font-family: 'Inter', 'Segoe UI', sans-serif !important;
}

/* Header */
.header-section {
    text-align: center;
    padding: 20px 0 10px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 16px;
    margin-bottom: 20px;
    color: white;
}

.header-section h1 {
    font-size: 2em;
    margin: 0;
    color: white !important;
}

.header-section p {
    opacity: 0.9;
    margin: 5px 0 0;
    font-size: 1.05em;
    color: #e8e8ff !important;
}

/* Chat area */
.chatbot {
    border-radius: 12px !important;
    border: 1px solid #e2e8f0 !important;
    min-height: 450px !important;
}

/* Source cards */
.source-card {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: 8px;
    padding: 10px 14px;
    margin: 4px 0;
    font-size: 0.9em;
}

.source-card strong {
    color: #6366f1;
}

/* Override dark mode */
.dark .source-card {
    background: #1e293b;
    border-color: #334155;
}

/* Buttons */
.primary-btn {
    background: linear-gradient(135deg, #667eea, #764ba2) !important;
    border: none !important;
    color: white !important;
    border-radius: 10px !important;
    font-weight: 600 !important;
    padding: 10px 24px !important;
}

.primary-btn:hover {
    opacity: 0.9 !important;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4) !important;
}
"""

# ─── Initialize chain on startup ────────────────────────────
print("🔄 Initializing Study Ocean AI Mentor...")
chain = get_chain()
print("✅ Ready to answer student doubts!\n")


def format_sources(sources: list) -> str:
    """Format source documents into a readable string."""
    if not sources:
        return ""
    
    lines = ["\n\n---\n📖 **Sources Referenced:**\n"]
    for i, src in enumerate(sources, 1):
        lines.append(f"**{i}.** `{src['subject']}` → _{src['file']}_")
    return "\n".join(lines)


def respond(message: str, chat_history: list) -> tuple:
    """Handle a student's question and return the mentor's response."""
    if not message.strip():
        return "", chat_history

    # Get answer from RAG chain
    result = ask_question(chain, message)
    answer = result["answer"]
    sources = result["sources"]

    # Append source references to the answer
    answer_with_sources = answer + format_sources(sources)

    # Update chat history
    chat_history.append((message, answer_with_sources))
    
    return "", chat_history


def clear_chat():
    """Clear the chat history."""
    return [], ""


# ─── Build Gradio Interface ─────────────────────────────────
with gr.Blocks(title="Study Ocean AI Mentor") as app:
    
    # Header
    gr.HTML("""
    <div class="header-section">
        <h1>🎓 Study Ocean AI Mentor</h1>
        <p>Ask any doubt from your study material — I'll explain it step by step!</p>
    </div>
    """)

    # Chatbot
    chatbot = gr.Chatbot(
        label="💬 Chat with Your Mentor",
        elem_classes=["chatbot"],
        height=480,
        avatar_images=(None, "https://api.dicebear.com/7.x/bottts/svg?seed=mentor&backgroundColor=6366f1"),
    )

    # Input area
    with gr.Row():
        msg = gr.Textbox(
            placeholder="Type your doubt here... e.g., 'Explain Newton's third law with examples'",
            label="Your Question",
            scale=5,
            lines=1,
            max_lines=3,
            show_label=False,
            container=False,
        )
        submit_btn = gr.Button("Ask 🚀", elem_classes=["primary-btn"], scale=1)

    # Action buttons
    with gr.Row():
        clear_btn = gr.Button("🗑️ Clear Chat", size="sm")

    # Example questions
    gr.Examples(
        examples=[
            "What are Newton's laws of motion? Explain with examples.",
            "Explain the difference between mitosis and meiosis.",
            "What is the Pythagorean theorem and how do I use it?",
            "Explain the concept of supply and demand in economics.",
            "What are the key features of the Indian Constitution?",
            "Solve: Find the derivative of f(x) = 3x² + 2x - 5",
        ],
        inputs=msg,
        label="💡 Try these example questions:",
    )

    # Tips section
    with gr.Accordion("📌 Tips for Better Answers", open=False):
        gr.Markdown("""
        - **Be specific**: Instead of "explain physics", ask "explain projectile motion with examples"
        - **Mention the topic**: "In organic chemistry, what is an SN2 reaction?"  
        - **Ask for steps**: "Solve step by step: integrate sin(x)cos(x) dx"
        - **Request comparisons**: "Compare TCP and UDP protocols"
        - **Ask for formulas**: "List all the trigonometric identities"
        """)

    # Event handlers
    msg.submit(respond, [msg, chatbot], [msg, chatbot])
    submit_btn.click(respond, [msg, chatbot], [msg, chatbot])
    clear_btn.click(clear_chat, outputs=[chatbot, msg])


# ─── Launch ─────────────────────────────────────────────────
if __name__ == "__main__":
    app.launch(
        server_name="0.0.0.0",
        server_port=7860,
        share=False,
        show_error=True,
        css=CUSTOM_CSS,
        theme=gr.themes.Soft(),
    )