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

ROOT="${LLM_REPRO_ROOT:-/mnt/DATA/git/llm-repro-ui}"
PYTHON="${PYTHON:-$ROOT/.venv/bin/python}"
HOST="${LLM_REPRO_HOST:-127.0.0.1}"
PORT="${LLM_REPRO_PORT:-8501}"
OPEN_BROWSER="${OPEN_BROWSER:-1}"

LOG_DIR="$ROOT/runs/dev-launcher"
SERVER_LOG="$LOG_DIR/streamlit.log"
URL="http://$HOST:$PORT"

server_pid=""

fail() {
  printf 'launch-dev: %s\n' "$*" >&2
  exit 1
}

port_is_free() {
  "$PYTHON" - "$1" "$2" <<'PY'
import socket
import sys

host = sys.argv[1]
port = int(sys.argv[2])
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as sock:
    sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
    try:
        sock.bind((host, port))
    except OSError:
        raise SystemExit(1)
PY
}

wait_for_url() {
  "$PYTHON" - "$1" <<'PY'
import sys
import time
import urllib.request

url = sys.argv[1]
deadline = time.monotonic() + 60
last_error = None
while time.monotonic() < deadline:
    try:
        with urllib.request.urlopen(url, timeout=2) as response:
            if 200 <= response.status < 500:
                raise SystemExit(0)
    except Exception as exc:  # noqa: BLE001 - printed only on timeout.
        last_error = exc
    time.sleep(1)
print(f"Timed out waiting for {url}: {last_error}", file=sys.stderr)
raise SystemExit(1)
PY
}

cleanup() {
  if [ -n "${server_pid:-}" ] && kill -0 "$server_pid" 2>/dev/null; then
    kill "$server_pid" 2>/dev/null || true
  fi
}
trap cleanup EXIT INT TERM

[ -x "$PYTHON" ] || fail "Python virtualenv not found at $PYTHON. Run: cd $ROOT && python -m venv .venv && . .venv/bin/activate && pip install -r requirements.txt"

mkdir -p "$LOG_DIR"
: > "$SERVER_LOG"

port_is_free "$HOST" "$PORT" || fail "$URL is already in use"

if [ -z "${OPENAI_API_KEY:-}" ] && { [ ! -f "$ROOT/.env" ] || ! grep -q '^OPENAI_API_KEY=sk-' "$ROOT/.env"; }; then
  printf 'Warning: OPENAI_API_KEY is not set in the environment or .env. The UI will start, but API calls need a key.\n' >&2
fi

printf 'Starting LLM Reproducibility Harness at %s\n' "$URL"
(
  cd "$ROOT"
  "$PYTHON" -m streamlit run app.py \
    --server.address "$HOST" \
    --server.port "$PORT" \
    --server.headless true
) >"$SERVER_LOG" 2>&1 &
server_pid="$!"

printf 'Waiting for %s\n' "$URL"
wait_for_url "$URL" || {
  tail -n 80 "$SERVER_LOG" >&2 || true
  fail "Streamlit did not become reachable"
}

if [ "$OPEN_BROWSER" = "1" ] && command -v xdg-open >/dev/null 2>&1; then
  xdg-open "$URL" >/dev/null 2>&1 || true
fi

cat <<EOF

LLM Reproducibility Harness is running.
Web UI: $URL

Log:
$SERVER_LOG

Press Ctrl+C to stop the server.
EOF

wait "$server_pid"