from __future__ import annotations

import os
import uuid
from pathlib import Path
from urllib.request import urlopen

from PIL import Image

from .base import BaseImageGen


ASSETS_DIR = "assets"
DEMO_IMAGE = os.path.join(ASSETS_DIR, "demo.jpg")


def ensure_demo_image() -> None:
    os.makedirs(ASSETS_DIR, exist_ok=True)
    if os.path.exists(DEMO_IMAGE):
        return

    url = "https://picsum.photos/1280/720"
    with urlopen(url, timeout=30) as resp:
        data = resp.read()
    with open(DEMO_IMAGE, "wb") as f:
        f.write(data)


class MockImageGen(BaseImageGen):
    def generate(self, prompt: dict[str, str], output_dir: str | Path) -> str:
        # prompt is accepted for interface consistency; mock uses only demo.jpg.
        _ = prompt
        ensure_demo_image()
        out_dir = Path(output_dir)
        out_dir.mkdir(parents=True, exist_ok=True)
        out_path = out_dir / f"shot_{uuid.uuid4().hex}.png"
        try:
            # Convert to PNG so verification criteria can match *.png.
            img = Image.open(DEMO_IMAGE).convert("RGB")
            img.save(str(out_path), format="PNG")
        except Exception:
            # Last-resort: if PNG conversion fails, still write a best-effort copy.
            out_path.write_bytes(Path(DEMO_IMAGE).read_bytes())
        return str(out_path)