app.py

"""
Gradio web interface for AI Examiner Agent.
Run:  python app.py
"""

import gradio as gr
from agent import ExaminerAgent

_agent: ExaminerAgent | None = None


def init_exam(api_key: str):
    """Called when the user clicks 'Start Exam'. Resets chat completely."""
    global _agent

    if not api_key.strip():
        return [{
            "role": "assistant",
            "content": "Please enter your Groq API key first."
        }], gr.update(interactive=False)

    try:
        _agent = ExaminerAgent(api_key.strip())
        opening = _agent.start()
        return [{"role": "assistant", "content": opening}], gr.update(interactive=True)
    except Exception as e:
        _agent = None
        err = str(e)
        if "401" in err or "invalid_api_key" in err or "Invalid API Key" in err:
            msg = "Invalid API key. Please check your Groq API key at console.groq.com and try again."
        elif "429" in err or "rate_limit" in err:
            msg = "Rate limit reached. Your daily token quota is exhausted. Please wait until tomorrow or upgrade your Groq plan."
        elif "403" in err:
            msg = "Access denied. Your API key does not have permission to use this model."
        elif "404" in err:
            msg = "Model not found. Please contact support."
        elif "connection" in err.lower() or "timeout" in err.lower():
            msg = "Connection error. Please check your internet connection and try again."
        else:
            msg = f"Error: {e}"
        return [{"role": "assistant", "content": msg}], gr.update(interactive=False)


def user_message(message: str, history: list):
    """Called when the student sends a message."""
    global _agent

    if not message.strip():
        return history, ""

    if _agent is None:
        return history + [
            {"role": "user", "content": message},
            {"role": "assistant", "content": "Please click Start Exam first."},
        ], ""

    # Block messages after exam is finished
    if _agent.exam_finished:
        return history + [
            {"role": "user", "content": message},
            {"role": "assistant", "content": "The exam is already finished. Click Start Exam to begin a new session."},
        ], ""

    history = history + [{"role": "user", "content": message}]

    try:
        reply = _agent.chat(message)
    except Exception as e:
        err = str(e)
        if "429" in err or "rate_limit" in err:
            reply = "Rate limit reached. Daily quota exhausted — please try again tomorrow."
        elif "401" in err or "invalid_api_key" in err:
            reply = "Invalid API key. Please restart and enter a valid Groq key."
        elif "connection" in err.lower() or "timeout" in err.lower():
            reply = "Connection error. Please check your internet and try again."
        elif "tool_use_failed" in err or "Failed to call a function" in err:
            # Leaked function call that wasn't caught — restart agent turn
            try:
                reply = _agent.chat("Please continue.")
            except Exception:
                reply = "Model error. Please try sending your message again."
        else:
            reply = f"Error: {e}"

    history = history + [{"role": "assistant", "content": reply}]
    return history, ""


# ─── UI ──────────────────────────────────────────────────────────────────────

CSS = """
@import url('https://fonts.googleapis.com/css2?family=Space+Mono:wght@400;700&family=Syne:wght@400;600;800&display=swap');

body, .gradio-container {
    background: #0d0f14 !important;
    font-family: 'Syne', sans-serif !important;
}

.title-block {
    text-align: center;
    padding: 2rem 1rem 1rem;
}
.title-block h1 {
    font-family: 'Syne', sans-serif;
    font-weight: 800;
    font-size: 2.6rem;
    letter-spacing: -1px;
    background: linear-gradient(135deg, #e2ff5d 0%, #00ffc2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin: 0;
}
.title-block p {
    color: #8b95a8;
    font-family: 'Space Mono', monospace;
    font-size: 0.82rem;
    margin-top: 0.4rem;
}

.gr-button-primary {
    background: linear-gradient(135deg, #e2ff5d, #00ffc2) !important;
    color: #0d0f14 !important;
    font-family: 'Space Mono', monospace !important;
    font-weight: 700 !important;
    border: none !important;
    border-radius: 6px !important;
}
.gr-button-primary:hover { filter: brightness(1.1) !important; }

label { color: #8b95a8 !important; font-family: 'Space Mono', monospace !important; font-size: 0.78rem !important; }
input, textarea { background: #141820 !important; border: 1px solid #2a3040 !important; color: #e8ecf4 !important; border-radius: 6px !important; }

.info-box {
    background: #141820;
    border: 1px solid #2a3040;
    border-radius: 8px;
    padding: 1rem 1.2rem;
    font-family: 'Space Mono', monospace;
    font-size: 0.75rem;
    color: #5a6478;
    line-height: 1.7;
}
.info-box strong { color: #e2ff5d; }
"""

with gr.Blocks(title="AI Examiner Agent") as demo:

    gr.HTML("""
    <div class="title-block">
        <h1>⬡ AI Examiner Agent</h1>
        <p>NLP course · oral exam simulation · powered by AI</p>
    </div>
    """)

    with gr.Row():
        with gr.Column(scale=1, min_width=260):
            gr.HTML("""
            <div class="info-box">
                <strong>How it works</strong><br>
                1. Paste your Groq API key<br>
                2. Click <em>Start Exam</em><br>
                3. Tell the bot your name &amp; email<br>
                4. Answer NLP questions<br>
                5. Get your score &amp; feedback
                <br><br>
                <strong>Demo students</strong><br>
                test@test.com / test
            </div>
            """)

            api_key = gr.Textbox(
                label="Groq API Key",
                placeholder="gsk_...",
                type="password",
                lines=1,
            )
            start_btn = gr.Button("▶ Start Exam", variant="primary")

        with gr.Column(scale=3):
            chatbot = gr.Chatbot(
                label="Exam Chat",
                height=520,
                show_label=False,
                layout="bubble",
            )
            with gr.Row():
                msg_input = gr.Textbox(
                    placeholder="Type your answer here…",
                    show_label=False,
                    lines=1,
                    scale=5,
                    interactive=False,
                )
                send_btn = gr.Button("Send →", scale=1, variant="primary")

    # Start Exam — clears chat history completely, creates new agent
    start_btn.click(
        fn=init_exam,
        inputs=[api_key],
        outputs=[chatbot, msg_input],
    )

    send_btn.click(
        fn=user_message,
        inputs=[msg_input, chatbot],
        outputs=[chatbot, msg_input],
    )

    msg_input.submit(
        fn=user_message,
        inputs=[msg_input, chatbot],
        outputs=[chatbot, msg_input],
    )


if __name__ == "__main__":
    demo.launch(share=False, css=CSS)