app.py

import spaces, json
import random
import re
import torch
import gradio as gr
from diffusers import ZImagePipeline

# ==================== Configuration ====================
MODEL_PATH = "Tongyi-MAI/Z-Image"

# ==================== Model Loading (Global Context) ====================
print(f"Loading Z-Image pipeline from {MODEL_PATH}...")
pipe = ZImagePipeline.from_pretrained(
    MODEL_PATH,
    torch_dtype=torch.bfloat16,
    low_cpu_mem_usage=False,
)
pipe.to("cuda")
print("Pipeline loaded successfully!")

# pipe.transformer.layers._repeated_blocks = ["ZImageTransformerBlock"]
# spaces.aoti_blocks_load(pipe.transformer.layers, "zerogpu-aoti/Z-Image", variant="fa3")


# ==================== Generation Function ====================
@spaces.GPU
def generate(
    prompt: str,
    negative_prompt: str = "",
    width=1024,
    height=1024,
    seed: int = 42,
    num_inference_steps: int = 50,
    guidance_scale: float = 4.0,
    cfg_normalization: bool = False,
    random_seed: bool = True,
    gallery_images: list = [],
    progress=gr.Progress(track_tqdm=True),
):

    if not prompt.strip():
        raise gr.Error("Please enter a prompt.")

    print("prompt: ", prompt)

    # Handle seed
    if random_seed:
        new_seed = random.randint(1, 1000000)
    else:
        new_seed = seed if seed != -1 else random.randint(1, 1000000)

    # Generate
    generator = torch.Generator("cuda").manual_seed(new_seed)

    image = pipe(
        prompt=prompt,
        negative_prompt=negative_prompt if negative_prompt.strip() else None,
        height=height,
        width=width,
        cfg_normalization=cfg_normalization,
        num_inference_steps=num_inference_steps,
        guidance_scale=guidance_scale,
        generator=generator,
    ).images[0]

    if not gallery_images: gallery_images = []
    gallery_images = [image] + gallery_images

    return gallery_images, int(new_seed)


def read_file(path: str) -> str:
    with open(path, 'r', encoding='utf-8') as f:
        content = f.read()
    return content

# ==================== Gradio Interface ====================

css = """
#col-container {
    margin: 0 auto;
    max-width: 960px;
}
h3{
    text-align: center;
    display:block;
}

"""
with open('examples/0_examples.json', 'r') as file: examples = json.load(file)

output_gallery = gr.Gallery(
    label="Generated Images",
    columns=2,
    rows=2,
    height=600,
    object_fit="contain",
    format="png",
    interactive=False,
)

with gr.Blocks(title="Z-Image Demo") as demo:
    with gr.Column(elem_id="col-container"):
        with gr.Column():
            gr.HTML(read_file("static/header.html"))

        with gr.Row():
            with gr.Column(scale=1):
                prompt_input = gr.Textbox(
                    label="Prompt",
                    lines=3,
                    placeholder="Enter your prompt here..."
                )
                negative_prompt_input = gr.Textbox(
                    label="Negative Prompt (optional)",
                    lines=2,
                    placeholder="Enter what you want to avoid..."
                )

                with gr.Row():
                    width = gr.Slider(
                        label="Width",
                        minimum=512,
                        maximum=2048,
                        step=32,
                        value=1024,
                    )

                    height = gr.Slider(
                        label="Height",
                        minimum=512,
                        maximum=2048,
                        step=32,
                        value=1024,
                    )

                with gr.Row():
                    seed = gr.Number(label="Seed", value=42, precision=0)
                    random_seed = gr.Checkbox(label="Random Seed", value=True)

                with gr.Row():
                    num_inference_steps = gr.Slider(
                        label="Inference Steps",
                        minimum=12,
                        maximum=50,
                        value=28,
                        step=1
                    )
                    guidance_scale = gr.Slider(
                        label="Guidance Scale (CFG)",
                        minimum=1.0,
                        maximum=10.0,
                        value=4.0,
                        step=0.1
                    )

                cfg_normalization = gr.Checkbox(
                    label="CFG Normalization",
                    value=False
                )

                generate_btn = gr.Button("Generate", variant="primary")

            with gr.Column(scale=1):
                output_gallery.render()

        gr.Examples(examples=examples, inputs=prompt_input,)
        gr.Markdown(read_file("static/footer.md"))

    generate_btn.click(
        generate,
        inputs=[
            prompt_input,
            negative_prompt_input,
            width,
            height,
            seed,
            num_inference_steps,
            guidance_scale,
            cfg_normalization,
            random_seed,
            output_gallery,
        ],
        outputs=[output_gallery, seed],
        api_name="generate",
    )


# ==================== Launch ====================
if __name__ == "__main__":
    demo.launch(
        server_name="0.0.0.0",
        server_port=7860,
        mcp_server=True,
        css=css
    )