#!/usr/bin/env bash
# Re-export the segmentation model that ships in core/dr-segment/models/.
#
# The .onnx is committed (D14), so this is not part of any build — it exists so
# the committed artefact is reproducible rather than a binary someone once
# produced and nobody can regenerate. Run it when bumping the model.
#
#   ./tools/export-seg-model.sh
#
# Requires `uv`. Everything else is fetched into a throwaway venv.
#
# ## Why these export flags
#
# `dynamic=False` is not a default we failed to change: **tract cannot parse
# the dynamic-shape graph at all**, failing shape inference on the neck's
# Concat. A fixed input shape is a hard requirement of the pure-Rust backend
# (see the workspace manifest for why that backend was chosen), and it is what
# makes the tiling option in `semantic.rs` the only route to more resolution.
#
# `imgsz` square rather than a rectangle matched to 3:2: one graph has to
# serve portrait, landscape, square crops and panoramas. A landscape-shaped
# graph trades letterbox waste on 3:2 for worse waste on everything else.
set -euo pipefail

HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO="$(cd "${HERE}/.." && pwd)"
OUT="${REPO}/core/dr-segment/models"

MODEL="${1:-yolo26n-seg}"
IMGSZ="${2:-640}"
WORK="$(mktemp -d)"
trap 'rm -rf "${WORK}"' EXIT

echo "==> exporting ${MODEL} at imgsz=${IMGSZ} in ${WORK}"
cd "${WORK}"
uv venv --python 3.12 venv
VIRTUAL_ENV="${WORK}/venv" uv pip install ultralytics onnx onnxslim

VIRTUAL_ENV="${WORK}/venv" "${WORK}/venv/bin/python" - "${MODEL}" "${IMGSZ}" <<'PY'
import sys, json
from ultralytics import YOLO

name = sys.argv[1]
imgsz = int(sys.argv[2])
m = YOLO(f"{name}.pt")
path = m.export(format="onnx", opset=17, simplify=True, imgsz=imgsz, dynamic=False)
print("ONNX:", path)

# The class names travel with the model rather than being retyped into Rust —
# a hand-copied vocabulary is a silent mismatch waiting to happen when the
# model is bumped.
with open("classes.json", "w") as f:
    json.dump([m.names[i] for i in range(len(m.names))], f, indent=1)
print("classes:", len(m.names))
PY

mkdir -p "${OUT}"
cp "${WORK}/${MODEL}.onnx" "${OUT}/${MODEL}.onnx"
cp "${WORK}/classes.json" "${OUT}/${MODEL}.classes.json"

echo "==> wrote:"
ls -la "${OUT}"
echo
echo "Remember: these weights are AGPL-3.0 (see ${OUT}/LICENCE.md)."