import argparse
import json
import subprocess
import sys
import time
from pathlib import Path

ap = argparse.ArgumentParser()
ap.add_argument("--input", action="append", default=[])
ap.add_argument("--outdir", required=True)
ap.add_argument("--params", default="{}")
a = ap.parse_args()
p = json.loads(a.params)

if not p.get("prompt"):
    print("ERROR: prompt is required")
    sys.exit(1)

model = p.get("model", "flux2-klein-4b")
steps = int(p.get("steps", 4))
outdir = Path(a.outdir)
out_png = outdir / f"flux_{model.replace('/', '_')}_s{p.get('seed', 42)}.png"
bindir = Path(sys.executable).parent

if model.startswith("flux2-"):
    cli = bindir / "mflux-generate-flux2"
    model_args = ["--model", model]
    quant_args = []           # klein is small; skip quantization flags
    guidance_args = []        # distilled klein: guidance fixed at 1.0
elif model == "schnell-4bit":
    cli = bindir / "mflux-generate"
    # ungated community pre-quantized weights (~10GB) — no HF license wall
    model_args = ["--model", "dhairyashil/FLUX.1-schnell-mflux-4bit",
                  "--base-model", "schnell"]
    quant_args = []
    guidance_args = []
else:
    cli = bindir / "mflux-generate"
    model_args = ["--model", model]
    quant = str(p.get("quantize", "8"))
    quant_args = ["--quantize", quant] if quant in ("4", "8") else []
    guidance_args = (["--guidance", str(p.get("guidance", 3.5))]
                     if model in ("dev", "krea-dev") else [])

if not cli.exists():
    print(f"ERROR: mflux not installed ({cli} missing). Run scripts/install_mflux.sh")
    sys.exit(1)

cmd = [str(cli), *model_args,
       "--prompt", p["prompt"],
       "--steps", str(steps),
       "--width", str(p.get("width", 1024)),
       "--height", str(p.get("height", 1024)),
       "--seed", str(p.get("seed", 42)),
       "--output", str(out_png),
       *quant_args, *guidance_args]

print("+", " ".join(cmd), flush=True)
print("(first run per model downloads weights from HuggingFace)", flush=True)
t0 = time.time()
res = subprocess.run(cmd, stdout=sys.stdout, stderr=subprocess.STDOUT)
if res.returncode != 0:
    print("HINT: gated-repo/auth errors mean this model needs an HF license accept "
          "+ token (Settings → HuggingFace token). flux2-klein-4b and schnell-4bit "
          "are ungated and need nothing.")
    sys.exit(res.returncode)
elapsed = round(time.time() - t0, 1)

if not out_png.exists():
    pngs = sorted(outdir.glob("*.png"))
    if not pngs:
        print("ERROR: no image produced")
        sys.exit(1)
    out_png = pngs[-1]

(outdir / "result.json").write_text(json.dumps({"outputs": [
    {"path": out_png.name,
     "meta": {"tool": "mflux", "model": model, "steps": steps,
              "seed": p.get("seed", 42), "seconds": elapsed}}]}))
print(f"done in {elapsed}s: {out_png.name}", flush=True)