#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
PORT="${1:-8888}"

if [[ "${1:-}" == "-h" || "${1:-}" == "--help" ]]; then
  cat <<'EOF'
Usage: ./scripts/start_jupyter.sh [port]

Starts repo-local JupyterLab from .venv with project-local config, runtime,
kernel registration, and notebook defaults.
EOF
  exit 0
fi

if ! [[ "$PORT" =~ ^[0-9]+$ ]]; then
  echo "Port must be an integer, got: $PORT" >&2
  exit 1
fi

if [[ ! -x "$ROOT_DIR/.venv/bin/python" ]]; then
  echo "Missing repo-local .venv at $ROOT_DIR/.venv" >&2
  echo "Create it first with: python3.12 -m venv .venv" >&2
  exit 1
fi

mkdir -p \
  "$ROOT_DIR/.cache/matplotlib" \
  "$ROOT_DIR/.ipython" \
  "$ROOT_DIR/.jupyter_config" \
  "$ROOT_DIR/.jupyter_data" \
  "$ROOT_DIR/.jupyter_runtime"

# Keep JupyterLab away from the broken Homebrew node installation on this machine.
export PATH="$ROOT_DIR/.venv/bin:/usr/bin:/bin:/usr/sbin:/sbin"
export JUPYTER_CONFIG_DIR="$ROOT_DIR/.jupyter_config"
export JUPYTER_DATA_DIR="$ROOT_DIR/.jupyter_data"
export JUPYTER_RUNTIME_DIR="$ROOT_DIR/.jupyter_runtime"
export IPYTHONDIR="$ROOT_DIR/.ipython"
export MPLCONFIGDIR="$ROOT_DIR/.cache/matplotlib"

KERNEL_DIR="$ROOT_DIR/.venv/share/jupyter/kernels/quantum-learning"
if [[ ! -f "$KERNEL_DIR/kernel.json" ]]; then
  "$ROOT_DIR/.venv/bin/python" -m ipykernel install \
    --sys-prefix \
    --name quantum-learning \
    --display-name "QuantumLearning (.venv)" \
    --env IPYTHONDIR "$IPYTHONDIR" \
    --env MPLCONFIGDIR "$MPLCONFIGDIR"
fi

exec "$ROOT_DIR/.venv/bin/jupyter" lab \
  --no-browser \
  --ip=127.0.0.1 \
  --port="$PORT"