import gradio as gr
from transformers import pipeline
import subprocess
import os
import pyttsx3
import shutil

# === TEXT SCRIPT GENERATOR ===
generator = pipeline("text-generation", model="gpt2")

def generate_script(prompt):
    result = generator(f"Scene: {prompt}\nDescription:", max_length=80, num_return_sequences=1)
    return result[0]["generated_text"]

# === VOICE GENERATOR using pyttsx3 (Fast + CPU Friendly)
def generate_voice(script):
    engine = pyttsx3.init()
    engine.setProperty('rate', 150)
    engine.save_to_file(script, 'voice.wav')
    engine.runAndWait()
    return "voice.wav"

# === BACKGROUND MUSIC MIXER ===
def merge_voice_and_music(voice_path, music_path, output_path="final_audio.wav"):
    command = [
        "ffmpeg", "-y",
        "-i", voice_path,
        "-i", music_path,
        "-filter_complex", "[1:0]volume=0.3[a1];[0:0][a1]amix=inputs=2:duration=shortest",
        "-c:a", "aac",
        "-shortest",
        output_path
    ]
    subprocess.call(command)
    return output_path

# === DUMMY VIDEO GENERATOR (use uploaded sample)
def generate_video(prompt):
    shutil.copyfile("sample.mp4", "modelscope_output.mp4")
    return "modelscope_output.mp4"

# === MERGE AUDIO + VIDEO ===
def merge_audio_video(audio_path, video_path):
    output = "final_output.mp4"
    subprocess.call([
        "ffmpeg", "-y", "-i", video_path, "-i", audio_path,
        "-c:v", "copy", "-c:a", "aac", "-shortest", output
    ])
    return output

# === FULL PIPELINE ===
def full_pipeline(prompt):
    script = generate_script(prompt)
    voice = generate_voice(script)
    final_audio = merge_voice_and_music(voice, "bg_music.mp3")
    video = generate_video(prompt)
    final_video = merge_audio_video(final_audio, video)
    return final_video, script

# === UI ===
with gr.Blocks() as demo:
    gr.Markdown("# 🎬 Free AI Reels Generator (CPU Only Version)")
    gr.Markdown("Script + Voice + Music + Video on 100% free CPU tier")

    with gr.Row():
        input_prompt = gr.Textbox(label="🎤 Scene Prompt", placeholder="e.g. A monk in the Himalayas walking through mist")
        generate_btn = gr.Button("Generate Reel")

    output_video = gr.Video(label="🎞️ Final Output")
    output_script = gr.Textbox(label="📝 Script")

    generate_btn.click(fn=full_pipeline, inputs=input_prompt, outputs=[output_video, output_script])

demo.launch()