app.py

import tempfile
import gradio as gr
import numpy as np
import soundfile as sf
import torch

from dia.model import Dia


# Load Nari model and config
print("Loading Nari model...")
try:
    # Use the function from inference.py
    model = Dia.from_pretrained("nari-labs/Dia-1.6B", compute_dtype="float32")
except Exception as e:
    print(f"Error loading Nari model: {e}")
    raise


@spaces.GPU
def run_inference(
    text_input: str,
    audio_prompt_input: Optional[Tuple[int, np.ndarray]],
    max_new_tokens: int,
    cfg_scale: float,
    temperature: float,
    top_p: float,
    cfg_filter_top_k: int,
    speed_factor: float,
):
    """
    Runs Nari inference using the globally loaded model and provided inputs.
    Uses temporary files for text and audio prompt compatibility with inference.generate.
    """
    # global model, device  # Access global model, config, device

    if not text_input or text_input.isspace():
        raise gr.Error("Text input cannot be empty.")

    temp_txt_file_path = None
    temp_audio_prompt_path = None
    output_audio = (44100, np.zeros(1, dtype=np.float32))

    try:
        prompt_path_for_generate = None
        if audio_prompt_input is not None:
            sr, audio_data = audio_prompt_input
            # Check if audio_data is valid
            if (
                audio_data is None or audio_data.size == 0 or audio_data.max() == 0
            ):  # Check for silence/empty
                gr.Warning("Audio prompt seems empty or silent, ignoring prompt.")
            else:
                # Save prompt audio to a temporary WAV file
                with tempfile.NamedTemporaryFile(
                    mode="wb", suffix=".wav", delete=False
                ) as f_audio:
                    temp_audio_prompt_path = f_audio.name  # Store path for cleanup

                    # Basic audio preprocessing for consistency
                    # Convert to float32 in [-1, 1] range if integer type
                    if np.issubdtype(audio_data.dtype, np.integer):
                        max_val = np.iinfo(audio_data.dtype).max
                        audio_data = audio_data.astype(np.float32) / max_val
                    elif not np.issubdtype(audio_data.dtype, np.floating):
                        gr.Warning(
                            f"Unsupported audio prompt dtype {audio_data.dtype}, attempting conversion."
                        )
                        # Attempt conversion, might fail for complex types
                        try:
                            audio_data = audio_data.astype(np.float32)
                        except Exception as conv_e:
                            raise gr.Error(
                                f"Failed to convert audio prompt to float32: {conv_e}"
                            )

                    # Ensure mono (average channels if stereo)
                    if audio_data.ndim > 1:
                        if audio_data.shape[0] == 2:  # Assume (2, N)
                            audio_data = np.mean(audio_data, axis=0)
                        elif audio_data.shape[1] == 2:  # Assume (N, 2)
                            audio_data = np.mean(audio_data, axis=1)
                        else:
                            gr.Warning(
                                f"Audio prompt has unexpected shape {audio_data.shape}, taking first channel/axis."
                            )
                            audio_data = (
                                audio_data[0]
                                if audio_data.shape[0] < audio_data.shape[1]
                                else audio_data[:, 0]
                            )
                        audio_data = np.ascontiguousarray(
                            audio_data
                        )  # Ensure contiguous after slicing/mean

                    # Write using soundfile
                    try:
                        sf.write(
                            temp_audio_prompt_path, audio_data, sr, subtype="FLOAT"
                        )  # Explicitly use FLOAT subtype
                        prompt_path_for_generate = temp_audio_prompt_path
                        print(
                            f"Created temporary audio prompt file: {temp_audio_prompt_path} (orig sr: {sr})"
                        )
                    except Exception as write_e:
                        print(f"Error writing temporary audio file: {write_e}")
                        raise gr.Error(f"Failed to save audio prompt: {write_e}")

        # 3. Run Generation

        start_time = time.time()

        # Use torch.inference_mode() context manager for the generation call
        with torch.inference_mode():
            output_audio_np = model.generate(
                text_input,
                max_tokens=max_new_tokens,
                cfg_scale=cfg_scale,
                temperature=temperature,
                top_p=top_p,
                cfg_filter_top_k=cfg_filter_top_k,  # Pass the value here
                use_torch_compile=False,  # Keep False for Gradio stability
                audio_prompt=prompt_path_for_generate,
            )

        end_time = time.time()
        print(f"Generation finished in {end_time - start_time:.2f} seconds.")

        # 4. Convert Codes to Audio
        if output_audio_np is not None:
            # Get sample rate from the loaded DAC model
            output_sr = 44100

            # --- Slow down audio ---
            original_len = len(output_audio_np)
            # Ensure speed_factor is positive and not excessively small/large to avoid issues
            speed_factor = max(0.1, min(speed_factor, 5.0))
            target_len = int(
                original_len / speed_factor
            )  # Target length based on speed_factor
            if (
                target_len != original_len and target_len > 0
            ):  # Only interpolate if length changes and is valid
                x_original = np.arange(original_len)
                x_resampled = np.linspace(0, original_len - 1, target_len)
                resampled_audio_np = np.interp(x_resampled, x_original, output_audio_np)
                output_audio = (
                    output_sr,
                    resampled_audio_np.astype(np.float32),
                )  # Use resampled audio
                print(
                    f"Resampled audio from {original_len} to {target_len} samples for {speed_factor:.2f}x speed."
                )
            else:
                output_audio = (
                    output_sr,
                    output_audio_np,
                )  # Keep original if calculation fails or no change
                print(f"Skipping audio speed adjustment (factor: {speed_factor:.2f}).")
            # --- End slowdown ---

            print(
                f"Audio conversion successful. Final shape: {output_audio[1].shape}, Sample Rate: {output_sr}"
            )

            # Explicitly convert to int16 to prevent Gradio warning
            if (
                output_audio[1].dtype == np.float32
                or output_audio[1].dtype == np.float64
            ):
                audio_for_gradio = np.clip(output_audio[1], -1.0, 1.0)
                audio_for_gradio = (audio_for_gradio * 32767).astype(np.int16)
                output_audio = (output_sr, audio_for_gradio)
                print("Converted audio to int16 for Gradio output.")

        else:
            print("\nGeneration finished, but no valid tokens were produced.")
            # Return default silence
            gr.Warning("Generation produced no output.")

    except Exception as e:
        print(f"Error during inference: {e}")
        import traceback

        traceback.print_exc()
        # Re-raise as Gradio error to display nicely in the UI
        raise gr.Error(f"Inference failed: {e}")

    finally:
        # 5. Cleanup Temporary Files defensively
        if temp_txt_file_path and Path(temp_txt_file_path).exists():
            try:
                Path(temp_txt_file_path).unlink()
                print(f"Deleted temporary text file: {temp_txt_file_path}")
            except OSError as e:
                print(
                    f"Warning: Error deleting temporary text file {temp_txt_file_path}: {e}"
                )
        if temp_audio_prompt_path and Path(temp_audio_prompt_path).exists():
            try:
                Path(temp_audio_prompt_path).unlink()
                print(f"Deleted temporary audio prompt file: {temp_audio_prompt_path}")
            except OSError as e:
                print(
                    f"Warning: Error deleting temporary audio prompt file {temp_audio_prompt_path}: {e}"
                )

    return output_audio


# --- Create Gradio Interface ---
css = """
#col-container {max-width: 90%; margin-left: auto; margin-right: auto;}
"""
# Attempt to load default text from example.txt
default_text = "[S1] Dia is an open weights text to dialogue model. \n[S2] You get full control over scripts and voices. \n[S1] Wow. Amazing. (laughs) \n[S2] Try it now on Git hub or Hugging Face."
example_txt_path = Path("./example.txt")
if example_txt_path.exists():
    try:
        default_text = example_txt_path.read_text(encoding="utf-8").strip()
        if not default_text:  # Handle empty example file
            default_text = "Example text file was empty."
    except Exception as e:
        print(f"Warning: Could not read example.txt: {e}")


# Build Gradio UI
with gr.Blocks(css=css) as demo:
    gr.Markdown("# Nari Text-to-Speech Synthesis")

    with gr.Row(equal_height=False):
        with gr.Column(scale=1):
            text_input = gr.Textbox(
                label="Input Text",
                placeholder="Enter text here...",
                value=default_text,
                lines=5,  # Increased lines
            )
            audio_prompt_input = gr.Audio(
                label="Audio Prompt (Optional)",
                show_label=True,
                sources=["upload", "microphone"],
                type="numpy",
            )
            with gr.Accordion("Generation Parameters", open=False):
                max_new_tokens = gr.Slider(
                    label="Max New Tokens (Audio Length)",
                    minimum=860,
                    maximum=3072,
                    value=model.config.data.audio_length,  # Use config default if available, else fallback
                    step=50,
                    info="Controls the maximum length of the generated audio (more tokens = longer audio).",
                )
                cfg_scale = gr.Slider(
                    label="CFG Scale (Guidance Strength)",
                    minimum=1.0,
                    maximum=5.0,
                    value=3.0,  # Default from inference.py
                    step=0.1,
                    info="Higher values increase adherence to the text prompt.",
                )
                temperature = gr.Slider(
                    label="Temperature (Randomness)",
                    minimum=1.0,
                    maximum=1.5,
                    value=1.3,  # Default from inference.py
                    step=0.05,
                    info="Lower values make the output more deterministic, higher values increase randomness.",
                )
                top_p = gr.Slider(
                    label="Top P (Nucleus Sampling)",
                    minimum=0.80,
                    maximum=1.0,
                    value=0.95,  # Default from inference.py
                    step=0.01,
                    info="Filters vocabulary to the most likely tokens cumulatively reaching probability P.",
                )
                cfg_filter_top_k = gr.Slider(
                    label="CFG Filter Top K",
                    minimum=15,
                    maximum=50,
                    value=30,
                    step=1,
                    info="Top k filter for CFG guidance.",
                )
                speed_factor_slider = gr.Slider(
                    label="Speed Factor",
                    minimum=0.8,
                    maximum=1.0,
                    value=0.94,
                    step=0.02,
                    info="Adjusts the speed of the generated audio (1.0 = original speed).",
                )

            run_button = gr.Button("Generate Audio", variant="primary")

        with gr.Column(scale=1):
            audio_output = gr.Audio(
                label="Generated Audio",
                type="numpy",
                autoplay=False,
            )

    # Link button click to function
    run_button.click(
        fn=run_inference,
        inputs=[
            text_input,
            audio_prompt_input,
            max_new_tokens,
            cfg_scale,
            temperature,
            top_p,
            cfg_filter_top_k,
            speed_factor_slider,
        ],
        outputs=[audio_output],  # Add status_output here if using it
        api_name="generate_audio",
    )

    # Add examples (ensure the prompt path is correct or remove it if example file doesn't exist)
    example_prompt_path = "./example_prompt.mp3"  # Adjust if needed
    examples_list = [
        [
            "[S1] Oh fire! Oh my goodness! What's the procedure? What to we do people? The smoke could be coming through an air duct! \n[S2] Oh my god! Okay.. it's happening. Everybody stay calm! \n[S1] What's the procedure... \n[S2] Everybody stay fucking calm!!!... Everybody fucking calm down!!!!! \n[S1] No! No! If you touch the handle, if its hot there might be a fire down the hallway! ",
            None,
            3072,
            3.0,
            1.3,
            0.95,
            35,
            0.94,
        ],
        [
            "[S1] Open weights text to dialogue model. \n[S2] You get full control over scripts and voices. \n[S1] I'm biased, but I think we clearly won. \n[S2] Hard to disagree. (laughs) \n[S1] Thanks for listening to this demo. \n[S2] Try it now on Git hub and Hugging Face. \n[S1] If you liked our model, please give us a star and share to your friends. \n[S2] This was Nari Labs.",
            example_prompt_path if Path(example_prompt_path).exists() else None,
            3072,
            3.0,
            1.3,
            0.95,
            35,
            0.94,
        ],
    ]

    if examples_list:
        gr.Examples(
            examples=examples_list,
            inputs=[
                text_input,
                audio_prompt_input,
                max_new_tokens,
                cfg_scale,
                temperature,
                top_p,
                cfg_filter_top_k,
                speed_factor_slider,
            ],
            outputs=[audio_output],
            fn=run_inference,
            cache_examples=False,
            label="Examples (Click to Run)",
        )
    else:
        gr.Markdown("_(No examples configured or example prompt file missing)_")

# --- Launch the App ---
if __name__ == "__main__":
    print("Launching Gradio interface...")

    # set `GRADIO_SERVER_NAME`, `GRADIO_SERVER_PORT` env vars to override default values
    # use `GRADIO_SERVER_NAME=0.0.0.0` for Docker
    demo.launch()