app.py

import gradio as gr
import openai
import requests
import subprocess
import uuid
import os

# Load OpenRouter key from Hugging Face secret
openai.api_key = os.environ.get("OPENROUTER_API_KEY")
openai.api_base = "https://openrouter.ai/api/v1"

def enhance_prompt(user_prompt):
    try:
        completion = openai.ChatCompletion.create(
            model="google/gemma-3n-e2b-it:free",
            messages=[
                {"role": "system", "content": "You are an expert in video storytelling. Expand the user prompt into a rich, visual scene description."},
                {"role": "user", "content": user_prompt}
            ]
        )
        return completion.choices[0].message.content
    except Exception as e:
        return user_prompt  # fallback

def generate_video(text, audio_file):
    uid = str(uuid.uuid4())
    enhanced_prompt = enhance_prompt(text)
    
    # Step 1: Generate AI video from Hugging Face free model (like AnimateDiff Lightning)
    video_url = f"https://huggingface.co/spaces/FFusion/AnimateDiff-Lightning/resolve/main/videos/sample.mp4"
    
    raw_video = f"{uid}_ai.mp4"
    final_video = f"{uid}_merged.mp4"
    
    try:
        # Download the sample video (Replace with real call later)
        r = requests.get(video_url)
        with open(raw_video, "wb") as f:
            f.write(r.content)
    except Exception as e:
        return f"❌ Error downloading AI video: {str(e)}"
    
    try:
        # Merge audio with the video using FFmpeg
        command = f"ffmpeg -y -i {raw_video} -i {audio_file} -map 0:v -map 1:a -shortest -c:v copy -c:a aac {final_video}"
        subprocess.call(command, shell=True)
    except Exception as e:
        return f"❌ FFmpeg error: {str(e)}"
    
    return final_video

demo = gr.Interface(
    fn=generate_video,
    inputs=[
        gr.Textbox(label="🎬 Enter Scene Prompt"),
        gr.Audio(type="filepath", label="🎙️ Upload Voiceover")
    ],
    outputs=gr.Video(label="📽️ Final AI Video"),
    title="AI Video Generator (OpenRouter + Hugging Face)",
    description="Uses OpenRouter to enhance your prompt, then generates a video and merges it with your voiceover."
)

demo.launch(share=True)