app.py

# app.py
"""
Gradio Space: GPT‑Image‑1 – BYOT playground  
Generate · Edit (paint mask!) · Variations
==========================================
Adds an **in‑browser paint tool** for the edit / inpaint workflow so users can
draw the mask directly instead of uploading one.

### How mask painting works
* Upload an image.  
* Use the *Mask* canvas to **paint the areas you’d like changed** (white =
  editable, black = keep).  
  Gradio’s built‑in *sketch* tool captures your brush strokes.
* The painted mask is converted to a 1‑channel PNG and sent to the
  `images.edit()` endpoint.

All other controls (size, quality, format, compression, n, background) stay the
same.
"""

from __future__ import annotations

import io
import os
from typing import List, Optional

import gradio as gr
import numpy as np
from PIL import Image
import openai

MODEL = "gpt-image-1"
SIZE_CHOICES = ["auto", "1024x1024", "1536x1024", "1024x1536"]
QUALITY_CHOICES = ["auto", "low", "medium", "high"]
FORMAT_CHOICES = ["png", "jpeg", "webp"]


def _client(key: str) -> openai.OpenAI:
    api_key = key.strip() or os.getenv("OPENAI_API_KEY", "")
    if not api_key:
        raise gr.Error("Please enter your OpenAI API key (never stored)")
    return openai.OpenAI(api_key=api_key)


def _img_list(resp, *, fmt: str, transparent: bool) -> List[str]:
    mime = "image/png" if fmt == "png" or transparent else f"image/{fmt}"
    return [
        f"data:{mime};base64,{d.b64_json}" if hasattr(d, "b64_json") else d.url
        for d in resp.data
    ]


def _common_kwargs(
    prompt: Optional[str],
    n: int,
    size: str,
    quality: str,
    out_fmt: str,
    compression: int,
    transparent_bg: bool,
):
    kwargs = dict(
        model=MODEL,
        n=n,
        size=size,
        quality=quality,
        output_format=out_fmt,
        transparent_background=transparent_bg,
        response_format="url" if out_fmt == "png" and not transparent_bg else "b64_json",
    )
    if prompt is not None:
        kwargs["prompt"] = prompt
    if out_fmt in {"jpeg", "webp"}:
        kwargs["compression"] = f"{compression}%"
    return kwargs


# ---------- Generate ---------- #

def generate(
    api_key: str,
    prompt: str,
    n: int,
    size: str,
    quality: str,
    out_fmt: str,
    compression: int,
    transparent_bg: bool,
):
    client = _client(api_key)
    try:
        resp = client.images.generate(**_common_kwargs(prompt, n, size, quality, out_fmt, compression, transparent_bg))
    except Exception as e:
        raise gr.Error(f"OpenAI error: {e}")
    return _img_list(resp, fmt=out_fmt, transparent=transparent_bg)


# ---------- Edit / Inpaint ---------- #

def _bytes_from_numpy(arr: np.ndarray) -> bytes:
    """Convert RGBA/RGB uint8 numpy array to PNG bytes."""
    img = Image.fromarray(arr.astype(np.uint8))
    out = io.BytesIO()
    img.save(out, format="PNG")
    return out.getvalue()


def edit_image(
    api_key: str,
    image_numpy: np.ndarray,
    mask_numpy: Optional[np.ndarray],
    prompt: str,
    n: int,
    size: str,
    quality: str,
    out_fmt: str,
    compression: int,
    transparent_bg: bool,
):
    if image_numpy is None:
        raise gr.Error("Please upload an image.")
    img_bytes = _bytes_from_numpy(image_numpy)

    mask_bytes: Optional[bytes] = None
    if mask_numpy is not None:
        # Convert painted area (alpha > 0) to white, else black; 1‑channel.
        if mask_numpy.shape[-1] == 4:  # RGBA from gr.Image sketch
            alpha = mask_numpy[:, :, 3]
        else:  # RGB
            alpha = np.any(mask_numpy != 0, axis=-1).astype(np.uint8) * 255
        bw = np.stack([alpha] * 3, axis=-1)  # 3‑channel white/black
        mask_bytes = _bytes_from_numpy(bw)

    client = _client(api_key)
    try:
        resp = client.images.edit(
            image=img_bytes,
            mask=mask_bytes,
            **_common_kwargs(prompt, n, size, quality, out_fmt, compression, transparent_bg),
        )
    except Exception as e:
        raise gr.Error(f"OpenAI error: {e}")
    return _img_list(resp, fmt=out_fmt, transparent=transparent_bg)


# ---------- Variations ---------- #

def variation_image(
    api_key: str,
    image_numpy: np.ndarray,
    n: int,
    size: str,
    quality: str,
    out_fmt: str,
    compression: int,
    transparent_bg: bool,
):
    if image_numpy is None:
        raise gr.Error("Please upload an image.")
    img_bytes = _bytes_from_numpy(image_numpy)
    client = _client(api_key)
    try:
        resp = client.images.variations(
            image=img_bytes,
            **_common_kwargs(None, n, size, quality, out_fmt, compression, transparent_bg),
        )
    except Exception as e:
        raise gr.Error(f"OpenAI error: {e}")
    return _img_list(resp, fmt=out_fmt, transparent=transparent_bg)


# ---------- UI ---------- #

def build_ui():
    with gr.Blocks(title="GPT‑Image‑1 (BYOT)") as demo:
        gr.Markdown("""# GPT‑Image‑1 Playground 🖼️🔑\nGenerate • Edit (paint mask) • Variations""")

        with gr.Accordion("🔐 API key", open=False):
            api = gr.Textbox(label="OpenAI API key", type="password", placeholder="sk‑…")

        # Common controls
        n_slider = gr.Slider(1, 10, value=1, step=1, label="Number of images (n)")
        size = gr.Dropdown(SIZE_CHOICES, value="auto", label="Size")
        quality = gr.Dropdown(QUALITY_CHOICES, value="auto", label="Quality")
        out_fmt = gr.Radio(FORMAT_CHOICES, value="png", label="Format")
        compression = gr.Slider(0, 100, value=75, step=1, label="Compression (JPEG/WebP)")
        transparent = gr.Checkbox(False, label="Transparent background (PNG only)")

        def _toggle_compression(fmt):
            return gr.update(visible=fmt in {"jpeg", "webp"})

        out_fmt.change(_toggle_compression, inputs=out_fmt, outputs=compression)

        with gr.Tabs():
            # ----- Generate Tab ----- #
            with gr.TabItem("Generate"):
                prompt_gen = gr.Textbox(label="Prompt", lines=2, placeholder="A photorealistic ginger cat astronaut on Mars")
                btn_gen = gr.Button("Generate 🚀")
                gallery_gen = gr.Gallery(columns=2, height="auto")
                btn_gen.click(
                    generate,
                    inputs=[api, prompt_gen, n_slider, size, quality, out_fmt, compression, transparent],
                    outputs=gallery_gen,
                )

            # ----- Edit Tab ----- #
            with gr.TabItem("Edit / Inpaint"):
                img_edit = gr.Image(label="Image", type="numpy")
                mask_canvas = gr.Image(label="Mask – paint white where the image should change", type="numpy", tool="sketch")
                prompt_edit = gr.Textbox(label="Edit prompt", lines=2, placeholder="Replace the sky with a starry night")
                btn_edit = gr.Button("Edit 🖌️")
                gallery_edit = gr.Gallery(columns=2, height="auto")
                btn_edit.click(
                    edit_image,
                    inputs=[api, img_edit, mask_canvas, prompt_edit, n_slider, size, quality, out_fmt, compression, transparent],
                    outputs=gallery_edit,
                )

            # ----- Variations Tab ----- #
            with gr.TabItem("Variations"):
                img_var = gr.Image(label="Source image", type="numpy")
                btn_var = gr.Button("Variations 🔄")
                gallery_var = gr.Gallery(columns=2, height="auto")
                btn_var.click(
                    variation_image,
                    inputs=[api, img_var, n_slider, size, quality, out_fmt, compression, transparent],
                    outputs=gallery_var,
                )

    return demo


demo = build_ui()

if __name__ == "__main__":
    demo.launch()