import gradio as gr
import requests
import os
import uuid

# --- Configuration ---
MODAL_BACKEND_URL = os.getenv("MODAL_BACKEND_URL", "").strip()

# --- UI Styling ---
CUSTOM_CSS = """
body { font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; }
.gradio-container { max-width: 800px !important; margin: auto; padding-top: 2rem; }
#chatbot {
    background-color: #F8F9FA;
    border-radius: 0.5rem;
    border: 1px solid #DEE2E6;
    min-height: 450px;
}
.message {
    padding: 1rem;
    border-radius: 0.5rem;
}
.message.user {
    background-color: #E9ECEF !important;
}
.message.bot {
    background-color: #FFFFFF !important;
    color: #343a40; /* Ensures text is visible on white background */
}
footer { display: none !important; }
"""

# --- Gradio UI Definition ---
with gr.Blocks(theme=gr.themes.Soft(), css=CUSTOM_CSS, title="MediAgent AI") as demo:
    # --- State Management ---
    conversation_state = gr.State(value={"history": []})
    session_id = gr.State(lambda: str(uuid.uuid4()))

    # --- Header ---
    gr.Markdown("""
    # 🧬 MediAgent AI (Conversational)
    _Your Smart, Role-Aware AI Health Navigator_
    """)

    # --- User Role Selection ---
    user_role = gr.Radio(
        ["patient", "doctor", "health_worker"],
        label="👤 Select Your Role",
        value="patient",
        info="The AI will adapt its communication style and questions based on your role."
    )

    # --- Chat Interface ---
    chatbot = gr.Chatbot(
        label="Conversation",
        elem_id="chatbot",
        bubble_full_width=False,
        avatar_images=(None, "https://i.imgur.com/9k2p4t7.png")
    )

    with gr.Row():
        user_textbox = gr.Textbox(
            scale=4,
            show_label=False,
            placeholder="Type your message here...",
            container=False,
        )
        submit_btn = gr.Button("Send", variant="primary", scale=1, min_width=150)

    with gr.Row():
        clear_btn = gr.ClearButton(
            value="🔄 Start New Conversation",
            components=[chatbot, user_textbox, conversation_state]
        )

    # --- Main UI Logic ---
    def handle_user_turn(
        user_input: str,
        chat_history: list,
        user_role_selection: str,
        current_state: dict,
        sid: str
    ):
        if not user_input.strip():
            return {chatbot: chat_history, conversation_state: current_state}

        chat_history.append((user_input, None))
        yield {chatbot: chat_history}

        if not MODAL_BACKEND_URL:
            error_message = "### ❗ Configuration Error\n**Reason**: `MODAL_BACKEND_URL` environment variable is not set. The administrator needs to configure the application."
            chat_history[-1] = (user_input, error_message)
            yield {chatbot: chat_history}
            return

        headers = {"Content-Type": "application/json"}
        payload = {
            "user_input": user_input,
            "session_id": sid,
            "user_role": user_role_selection,
            "conversation_state": current_state
        }

        try:
            response = requests.post(MODAL_BACKEND_URL, headers=headers, json=payload, timeout=300)
            response.raise_for_status()
            backend_response = response.json()
            bot_response_text = backend_response.get("response_text", "Sorry, I received an empty response.")
            new_state = backend_response.get("conversation_state", current_state)
        except requests.exceptions.RequestException as e:
            bot_response_text = f"### ❗ Network Error\n**Reason**: Could not connect to the backend.\n**Details**: {str(e)}"
            new_state = current_state

        chat_history[-1] = (user_input, bot_response_text)
        yield {chatbot: chat_history, conversation_state: new_state}

    # --- Event Listeners ---
    submit_event = submit_btn.click(
        fn=handle_user_turn,
        inputs=[user_textbox, chatbot, user_role, conversation_state, session_id],
        outputs=[chatbot, conversation_state],
        show_progress="hidden"
    ).then(lambda: gr.update(value=""), outputs=[user_textbox])

    textbox_event = user_textbox.submit(
        fn=handle_user_turn,
        inputs=[user_textbox, chatbot, user_role, conversation_state, session_id],
        outputs=[chatbot, conversation_state],
        show_progress="hidden"
    ).then(lambda: gr.update(value=""), outputs=[user_textbox])

    @clear_btn.click
    def clear_chat():
        return {"history": []}

if __name__ == "__main__":
    print("Gradio App Starting...")
    if not MODAL_BACKEND_URL:
        print("\nWARNING: The `MODAL_BACKEND_URL` environment variable is not set.")
        print("The application will run, but will show a configuration error.\n")
    demo.queue()
    demo.launch()