app.py

# import os
import re
import torch
import tempfile
from scipy.io.wavfile import write
from pydub import AudioSegment
from dotenv import load_dotenv
import spaces
import gradio as gr

# Transformers & Models
from transformers import (
    AutoTokenizer,
    AutoModelForCausalLM,
    pipeline,
    AutoProcessor,
    MusicgenForConditionalGeneration,
)
# Coqui TTS
from TTS.api import TTS

# ---------------------------------------------------------------------
# Load Environment Variables
# ---------------------------------------------------------------------
load_dotenv()
HF_TOKEN = os.getenv("HF_TOKEN")

# ---------------------------------------------------------------------
# Global Model Caches
# ---------------------------------------------------------------------
LLAMA_PIPELINES = {}
MUSICGEN_MODELS = {}
TTS_MODELS = {}

# ---------------------------------------------------------------------
# Utility Function: Clean Text
# ---------------------------------------------------------------------
def clean_text(text: str) -> str:
    """
    Removes undesired characters (e.g., asterisks) that might not be recognized by the model's vocabulary.
    """
    # Remove all asterisks. You can add more cleaning steps here as needed.
    return re.sub(r'\*', '', text)

# ---------------------------------------------------------------------
# Helper Functions
# ---------------------------------------------------------------------
def get_llama_pipeline(model_id: str, token: str):
    """
    Returns a cached LLaMA pipeline if available; otherwise, loads it.
    """
    if model_id in LLAMA_PIPELINES:
        return LLAMA_PIPELINES[model_id]

    tokenizer = AutoTokenizer.from_pretrained(model_id, use_auth_token=token)
    model = AutoModelForCausalLM.from_pretrained(
        model_id,
        use_auth_token=token,
        torch_dtype=torch.float16,
        device_map="auto",
        trust_remote_code=True,
    )
    text_pipeline = pipeline("text-generation", model=model, tokenizer=tokenizer)
    LLAMA_PIPELINES[model_id] = text_pipeline
    return text_pipeline


def get_musicgen_model(model_key: str = "facebook/musicgen-large"):
    """
    Returns a cached MusicGen model if available; otherwise, loads it.
    Uses the 'large' variant for higher quality outputs.
    """
    if model_key in MUSICGEN_MODELS:
        return MUSICGEN_MODELS[model_key]

    model = MusicgenForConditionalGeneration.from_pretrained(model_key)
    processor = AutoProcessor.from_pretrained(model_key)

    device = "cuda" if torch.cuda.is_available() else "cpu"
    model.to(device)
    MUSICGEN_MODELS[model_key] = (model, processor)
    return model, processor


def get_tts_model(model_name: str = "tts_models/en/ljspeech/tacotron2-DDC"):
    """
    Returns a cached TTS model if available; otherwise, loads it.
    """
    if model_name in TTS_MODELS:
        return TTS_MODELS[model_name]

    tts_model = TTS(model_name)
    TTS_MODELS[model_name] = tts_model
    return tts_model


# ---------------------------------------------------------------------
# Script Generation Function
# ---------------------------------------------------------------------
@spaces.GPU(duration=100)
def generate_script(user_prompt: str, model_id: str, token: str, duration: int):
    """
    Generates a script, sound design suggestions, and music ideas from a user prompt.
    Returns a tuple of strings: (voice_script, sound_design, music_suggestions).
    """
    try:
        text_pipeline = get_llama_pipeline(model_id, token)

        system_prompt = (
            "You are an expert radio imaging producer specializing in sound design and music. "
            f"Based on the user's concept and the selected duration of {duration} seconds, produce the following: "
            "1. A concise voice-over script. Prefix this section with 'Voice-Over Script:'.\n"
            "2. Suggestions for sound design. Prefix this section with 'Sound Design Suggestions:'.\n"
            "3. Music styles or track recommendations. Prefix this section with 'Music Suggestions:'."
        )
        combined_prompt = f"{system_prompt}\nUser concept: {user_prompt}\nOutput:"

        with torch.inference_mode():
            result = text_pipeline(
                combined_prompt,
                max_new_tokens=300,
                do_sample=True,
                temperature=0.8
            )

        generated_text = result[0]["generated_text"]
        if "Output:" in generated_text:
            generated_text = generated_text.split("Output:")[-1].strip()

        # Default placeholders
        voice_script = "No voice-over script found."
        sound_design = "No sound design suggestions found."
        music_suggestions = "No music suggestions found."

        # Voice-Over Script
        if "Voice-Over Script:" in generated_text:
            parts = generated_text.split("Voice-Over Script:")
            voice_script_part = parts[1]
            if "Sound Design Suggestions:" in voice_script_part:
                voice_script = voice_script_part.split("Sound Design Suggestions:")[0].strip()
            else:
                voice_script = voice_script_part.strip()

        # Sound Design
        if "Sound Design Suggestions:" in generated_text:
            parts = generated_text.split("Sound Design Suggestions:")
            sound_design_part = parts[1]
            if "Music Suggestions:" in sound_design_part:
                sound_design = sound_design_part.split("Music Suggestions:")[0].strip()
            else:
                sound_design = sound_design_part.strip()

        # Music Suggestions
        if "Music Suggestions:" in generated_text:
            parts = generated_text.split("Music Suggestions:")
            music_suggestions = parts[1].strip()

        return voice_script, sound_design, music_suggestions

    except Exception as e:
        return f"Error generating script: {e}", "", ""


# ---------------------------------------------------------------------
# Voice-Over Generation Function
# ---------------------------------------------------------------------
@spaces.GPU(duration=100)
def generate_voice(script: str, tts_model_name: str = "tts_models/en/ljspeech/tacotron2-DDC"):
    """
    Generates a voice-over from the provided script using the Coqui TTS model.
    Returns the file path to the generated .wav file.
    """
    try:
        if not script.strip():
            return "Error: No script provided."

        # Clean the script to remove special characters (e.g., asterisks) that may produce warnings
        cleaned_script = clean_text(script)

        tts_model = get_tts_model(tts_model_name)

        # Generate and save voice
        output_path = os.path.join(tempfile.gettempdir(), "voice_over.wav")
        tts_model.tts_to_file(text=cleaned_script, file_path=output_path)
        return output_path

    except Exception as e:
        return f"Error generating voice: {e}"


# ---------------------------------------------------------------------
# Music Generation Function
# ---------------------------------------------------------------------
@spaces.GPU(duration=200)
def generate_music(prompt: str, audio_length: int):
    """
    Generates music from the 'facebook/musicgen-large' model based on the prompt.
    Returns the file path to the generated .wav file.
    """
    try:
        if not prompt.strip():
            return "Error: No music suggestion provided."

        model_key = "facebook/musicgen-large"
        musicgen_model, musicgen_processor = get_musicgen_model(model_key)

        device = "cuda" if torch.cuda.is_available() else "cpu"
        inputs = musicgen_processor(text=[prompt], padding=True, return_tensors="pt").to(device)

        with torch.inference_mode():
            outputs = musicgen_model.generate(**inputs, max_new_tokens=audio_length)

        audio_data = outputs[0, 0].cpu().numpy()
        normalized_audio = (audio_data / max(abs(audio_data)) * 32767).astype("int16")

        output_path = os.path.join(tempfile.gettempdir(), "musicgen_large_generated_music.wav")
        write(output_path, 44100, normalized_audio)

        return output_path

    except Exception as e:
        return f"Error generating music: {e}"


# ---------------------------------------------------------------------
# Audio Blending with Duration Sync & Ducking
# ---------------------------------------------------------------------
@spaces.GPU(duration=100)
def blend_audio(voice_path: str, music_path: str, ducking: bool, duck_level: int = 10):
    """
    Blends two audio files (voice and music).
    1. If music < voice, loops the music until it meets/exceeds the voice duration.
    2. If music > voice, trims music to the voice duration.
    3. If ducking=True, the music is attenuated by 'duck_level' dB while the voice is playing.
    Returns the file path to the blended .wav file.
    """
    try:
        if not os.path.isfile(voice_path) or not os.path.isfile(music_path):
            return "Error: Missing audio files for blending."

        voice = AudioSegment.from_wav(voice_path)
        music = AudioSegment.from_wav(music_path)

        voice_len = len(voice)  # in milliseconds
        music_len = len(music)  # in milliseconds

        # Loop music if it's shorter than the voice
        if music_len < voice_len:
            looped_music = AudioSegment.empty()
            while len(looped_music) < voice_len:
                looped_music += music
            music = looped_music

        # Trim music if it's longer than the voice
        if len(music) > voice_len:
            music = music[:voice_len]

        if ducking:
            ducked_music = music - duck_level
            final_audio = ducked_music.overlay(voice)
        else:
            final_audio = music.overlay(voice)

        output_path = os.path.join(tempfile.gettempdir(), "blended_output.wav")
        final_audio.export(output_path, format="wav")
        return output_path

    except Exception as e:
        return f"Error blending audio: {e}"


# ---------------------------------------------------------------------
# Gradio Interface with Enhanced UI
# ---------------------------------------------------------------------
with gr.Blocks(css="""
    /* Global Styles */
    body {
        background: linear-gradient(135deg, #1d1f21, #3a3d41);
        color: #f0f0f0;
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    }
    .header {
        text-align: center;
        padding: 2rem 1rem;
        background: linear-gradient(90deg, #6a11cb, #2575fc);
        border-radius: 0 0 20px 20px;
        margin-bottom: 2rem;
    }
    .header h1 {
        margin: 0;
        font-size: 2.5rem;
    }
    .header p {
        font-size: 1.2rem;
    }
    .gradio-container {
        background: #2e2e2e;
        border-radius: 10px;
        padding: 1rem;
    }
    .tab-title {
        font-size: 1.1rem;
        font-weight: bold;
    }
    .footer {
        text-align: center;
        font-size: 0.9em;
        margin-top: 2rem;
        padding: 1rem;
        color: #cccccc;
    }
""") as demo:

    # Custom Header
    with gr.Row(elem_classes="header"):
        gr.Markdown("""
        <h1>🎧 AI Ads Promo</h1>
        <p>Your all-in-one AI solution for crafting engaging audio ads. <br><em>Demo MVP</em></p>
        """)

    gr.Markdown("""
    Welcome to **AI Ads Promo (Demo MVP)**! This platform leverages state-of-the-art AI models to help you generate:
    
    - **Script**: Generate a compelling voice-over script with LLaMA.
    - **Voice Synthesis**: Create natural-sounding voice-overs using Coqui TTS.
    - **Music Production**: Produce custom music tracks with MusicGen.
    - **Audio Blending**: Seamlessly blend voice and music with options for ducking.
    """)

    with gr.Tabs():
        # Step 1: Generate Script
        with gr.Tab("📝 Script Generation"):
            with gr.Row():
                user_prompt = gr.Textbox(
                    label="Promo Idea", 
                    placeholder="E.g., A 30-second promo for a morning show...",
                    lines=2
                )
            with gr.Row():
                llama_model_id = gr.Textbox(
                    label="LLaMA Model ID", 
                    value="meta-llama/Meta-Llama-3-8B-Instruct", 
                    placeholder="Enter a valid Hugging Face model ID"
                )
                duration = gr.Slider(
                    label="Desired Promo Duration (seconds)",
                    minimum=15, 
                    maximum=60, 
                    step=15, 
                    value=30
                )
            generate_script_button = gr.Button("Generate Script", variant="primary")
            script_output = gr.Textbox(label="Generated Voice-Over Script", lines=5, interactive=False)
            sound_design_output = gr.Textbox(label="Sound Design Suggestions", lines=3, interactive=False)
            music_suggestion_output = gr.Textbox(label="Music Suggestions", lines=3, interactive=False)

            generate_script_button.click(
                fn=lambda user_prompt, model_id, dur: generate_script(user_prompt, model_id, HF_TOKEN, dur),
                inputs=[user_prompt, llama_model_id, duration],
                outputs=[script_output, sound_design_output, music_suggestion_output],
            )

        # Step 2: Generate Voice
        with gr.Tab("🎤 Voice Synthesis"):
            gr.Markdown("Generate a natural-sounding voice-over using Coqui TTS.")
            selected_tts_model = gr.Dropdown(
                label="TTS Model",
                choices=[
                    "tts_models/en/ljspeech/tacotron2-DDC",  
                    "tts_models/en/ljspeech/vits", 
                    "tts_models/en/sam/tacotron-DDC", 
                ],
                value="tts_models/en/ljspeech/tacotron2-DDC",
                multiselect=False
            )
            generate_voice_button = gr.Button("Generate Voice-Over", variant="primary")
            voice_audio_output = gr.Audio(label="Voice-Over (WAV)", type="filepath")

            generate_voice_button.click(
                fn=lambda script, tts_model: generate_voice(script, tts_model),
                inputs=[script_output, selected_tts_model],
                outputs=voice_audio_output,
            )

        # Step 3: Generate Music
        with gr.Tab("🎶 Music Production"):
            gr.Markdown("Generate a custom music track using the **MusicGen Large** model.")
            audio_length = gr.Slider(
                label="Music Length (tokens)",
                minimum=128, 
                maximum=1024, 
                step=64, 
                value=512,
                info="Increase tokens for longer audio (inference time may vary)."
            )
            generate_music_button = gr.Button("Generate Music", variant="primary")
            music_output = gr.Audio(label="Generated Music (WAV)", type="filepath")

            generate_music_button.click(
                fn=lambda music_suggestion, length: generate_music(music_suggestion, length),
                inputs=[music_suggestion_output, audio_length],
                outputs=[music_output],
            )

        # Step 4: Blend Audio
        with gr.Tab("🎚️ Audio Blending"):
            gr.Markdown("Blend your voice-over and music track. Music will be looped/truncated to match the voice duration. Enable ducking to lower the music during voice segments.")
            ducking_checkbox = gr.Checkbox(label="Enable Ducking?", value=True)
            duck_level_slider = gr.Slider(
                label="Ducking Level (dB attenuation)", 
                minimum=0, 
                maximum=20, 
                step=1, 
                value=10
            )
            blend_button = gr.Button("Blend Voice + Music", variant="primary")
            blended_output = gr.Audio(label="Final Blended Output (WAV)", type="filepath")

            blend_button.click(
                fn=blend_audio,
                inputs=[voice_audio_output, music_output, ducking_checkbox, duck_level_slider],
                outputs=blended_output
            )

    # Footer
    gr.Markdown("""
    <div class="footer">
        <hr>
        Created with ❤️ by <a href="https://bilsimaging.com" target="_blank" style="color: #88aaff;">bilsimaging.com</a>
        <br>
        <small>AI Ads Promo (Demo MVP) &copy; 2025</small>
    </div>
    """)
    
    # Visitor Badge
    gr.HTML("""
    <div style="text-align: center; margin-top: 1rem;">
        <a href="https://visitorbadge.io/status?path=https%3A%2F%2Fhuggingface.co%2Fspaces%2FBils%2Fradiogold">
            <img src="https://api.visitorbadge.io/api/visitors?path=https%3A%2F%2Fhuggingface.co%2Fspaces%2FBils%2Fradiogold&countColor=%23263759" alt="visitor badge"/>
        </a>
    </div>
    """)

demo.launch(debug=True)