import gradio as gr
import requests

API_URL = "https://openrouter.ai/api/v1/chat/completions"

def generate_cover_letter(resume, job_desc):
    prompt = f"""
You are a career expert. Write a personalized, ATS-friendly cover letter for this resume and job description.

Resume:
{resume}

Job Description:
{job_desc}
"""
    
    headers = {
        "Content-Type": "application/json"
        # No API key required for free models
    }

    data = {
        "model": "meta-llama/llama-4-maverick:free",
        "messages": [
            {"role": "user", "content": prompt}
        ]
    }

    try:
        response = requests.post(API_URL, headers=headers, json=data)
        if response.status_code == 200:
            return response.json()["choices"][0]["message"]["content"]
        else:
            return f"❌ API Error {response.status_code}: {response.text}"
    except Exception as e:
        return f"❌ Failed to connect to OpenRouter: {str(e)}"

# Gradio UI
demo = gr.Interface(
    fn=generate_cover_letter,
    inputs=[
        gr.Textbox(lines=12, label="Paste Your Resume"),
        gr.Textbox(lines=10, label="Paste Job Description")
    ],
    outputs=gr.Textbox(label="Generated Cover Letter"),
    title="AI Cover Letter Generator",
    description="No API key needed — powered by LLaMA 4 Maverick (free via OpenRouter). Just paste your resume and job description to get a tailored cover letter."
)

demo.launch()