app.py

import gradio as gr
import os
from openai import OpenAI

# Initialize OpenRouter client
client = OpenAI(
    base_url="https://openrouter.ai/api/v1",
    api_key=os.environ.get("OPENROUTER_API_KEY"),
)

def generate_subject_lines(email_body, tone, num_suggestions):
    """Generate email subject lines based on content and tone."""
    
    if not email_body.strip():
        return "Please enter email content."
    
    # Construct the prompt
    prompt = f"""Generate {num_suggestions} compelling email subject lines for the following email content.

Tone: {tone}

Email content:
{email_body}

Requirements:
- Make them attention-grabbing but not clickbait
- Keep them under 60 characters when possible
- Match the {tone} tone
- Make each one distinct

Provide only the subject lines, numbered 1-{num_suggestions}."""

    try:
        # Call OpenRouter API with a free model
        response = client.chat.completions.create(
            model="google/gemma-2-9b-it:free",  # Free model on OpenRouter
            messages=[
                {"role": "user", "content": prompt}
            ],
            max_tokens=500,
            temperature=0.8,
        )
        
        result = response.choices[0].message.content
        return result
        
    except Exception as e:
        return f"Error: {str(e)}\n\nMake sure your OPENROUTER_API_KEY is set correctly."

# Create Gradio interface
with gr.Blocks(title="Email Subject Line Generator", theme=gr.themes.Soft()) as demo:
    gr.Markdown("""
    # 📧 Smart Email Subject Line Generator
    
    Generate compelling subject lines for your emails using AI. Perfect for:
    - Business emails
    - Marketing campaigns
    - Cold outreach
    - Newsletter titles
    """)
    
    with gr.Row():
        with gr.Column():
            email_input = gr.Textbox(
                label="Email Content",
                placeholder="Paste your email content here...",
                lines=10
            )
            
            tone_select = gr.Radio(
                choices=["Professional", "Friendly", "Urgent", "Casual", "Formal"],
                label="Tone",
                value="Professional"
            )
            
            num_select = gr.Slider(
                minimum=3,
                maximum=10,
                value=5,
                step=1,
                label="Number of Suggestions"
            )
            
            generate_btn = gr.Button("Generate Subject Lines", variant="primary")
        
        with gr.Column():
            output = gr.Textbox(
                label="Generated Subject Lines",
                lines=15,
                show_copy_button=True
            )
    
    # Example emails
    gr.Markdown("### 📝 Try These Examples:")
    gr.Examples(
        examples=[
            [
                "Hi there,\n\nI wanted to reach out about our new productivity tool that's helped over 5,000 teams save 10+ hours per week. We're offering a free 30-day trial for early adopters. Would you be interested in a quick demo?\n\nBest regards",
                "Professional",
                5
            ],
            [
                "Hey team,\n\nQuick reminder that our monthly all-hands meeting is tomorrow at 2 PM. We'll be discussing Q4 goals and the new office policy. Please come prepared with questions!\n\nSee you there!",
                "Friendly",
                4
            ],
        ],
        inputs=[email_input, tone_select, num_select],
        label=None
    )
    
    # Connect the button
    generate_btn.click(
        fn=generate_subject_lines,
        inputs=[email_input, tone_select, num_select],
        outputs=output
    )

# Launch the app
if __name__ == "__main__":
    demo.launch()