import os
import requests
import traceback
import gradio as gr
from dotenv import load_dotenv

# Load secrets (from Hugging Face Spaces "Variables and secrets")
load_dotenv()

# Configuration
OPENROUTER_API_KEY = os.getenv("OPENROUTER_API_KEY")
OPENROUTER_MODEL = os.getenv("OPENROUTER_MODEL")
APP_TITLE = os.getenv("APP_TITLE", "Selva Chat Bot")
OPENROUTER_URL = "https://openrouter.ai/api/v1/chat/completions"


def chatbot_fn(message, history):
    """
    message: latest user input (string)
    history: list of tuples (user, bot)
    """
    try:
        if not OPENROUTER_API_KEY:
            return history + [(message, "❌ API key not configured.")]

        # Convert Gradio history to OpenRouter messages format
        messages = [{"role": "system", "content": "You are a helpful, concise, and friendly assistant for Selva's Chat-Bot."}]
        for user_msg, bot_msg in history:
            messages.append({"role": "user", "content": user_msg})
            messages.append({"role": "assistant", "content": bot_msg})

        # Add latest user query
        messages.append({"role": "user", "content": message})

        # API request
        headers = {
            "Authorization": f"Bearer {OPENROUTER_API_KEY}",
            "Content-Type": "application/json",
            "X-Title": APP_TITLE,
        }
        body = {
            "model": OPENROUTER_MODEL,
            "messages": messages,
            "temperature": 0.7,
            "max_tokens": 1000,
        }

        response = requests.post(OPENROUTER_URL, headers=headers, json=body, timeout=30)

        if response.status_code != 200:
            error_data = response.json() if response.headers.get('content-type') == 'application/json' else {"error": response.text}
            error_message = error_data.get("error", "API request failed")
            return history + [(message, f"❌ Error: {error_message}")]

        data = response.json()
        reply = (
            data.get("choices", [{}])[0]
            .get("message", {})
            .get("content", "Sorry, I couldn't generate a response.")
        )

        return history + [(message, reply)]

    except requests.exceptions.Timeout:
        return history + [(message, "❌ Request timeout. Please try again.")]
    except Exception as e:
        traceback.print_exc()
        return history + [(message, f"❌ Internal error: {e}")]


# Gradio Chatbot UI
with gr.Blocks(title=APP_TITLE) as demo:
    gr.Markdown(f"# 🤖 {APP_TITLE}")
    chatbot = gr.Chatbot(height=500)
    msg = gr.Textbox(placeholder="Type your message here...")
    clear = gr.Button("Clear")

    def user_submit(user_message, chat_history):
        return "", chatbot_fn(user_message, chat_history)

    msg.submit(user_submit, [msg, chatbot], [msg, chatbot])
    clear.click(lambda: None, None, chatbot, queue=False)

# Hugging Face Spaces entrypoint
if __name__ == "__main__":
    demo.launch(server_name="0.0.0.0", server_port=7860, debug=True, pwa=True)