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

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
APP_HOME="$(cd "${SCRIPT_DIR}/.." && pwd)"
CONFIG_FILE="${APP_HOME}/config/catalogsync.env"
RUN_DIR="${APP_HOME}/run"
LOCK_DIR="${RUN_DIR}/serve.lock"
PID_FILE="${RUN_DIR}/serve.pid"
# shellcheck source=./load_env.sh
source "${SCRIPT_DIR}/load_env.sh"

fail() {
  echo "[serve_console.sh] ERROR: $*" >&2
  exit 1
}

require_var() {
  local var_name="$1"
  if [[ -z "${!var_name:-}" ]]; then
    fail "Missing required config variable: ${var_name} (from ${CONFIG_FILE})"
  fi
}

acquire_serve_lock() {
  mkdir -p "${RUN_DIR}"
  if mkdir "${LOCK_DIR}" 2>/dev/null; then
    echo "$$" > "${LOCK_DIR}/owner_pid"
    return 0
  fi

  local owner_pid=""
  if [[ -f "${LOCK_DIR}/owner_pid" ]]; then
    owner_pid="$(cat "${LOCK_DIR}/owner_pid" 2>/dev/null || true)"
  fi
  if [[ -n "${owner_pid}" ]] && kill -0 "${owner_pid}" 2>/dev/null; then
    fail "Another serve_console instance is running (owner_pid=${owner_pid})"
  fi

  rm -rf "${LOCK_DIR}"
  if ! mkdir "${LOCK_DIR}" 2>/dev/null; then
    fail "Cannot acquire serve lock: ${LOCK_DIR}"
  fi
  echo "$$" > "${LOCK_DIR}/owner_pid"
}

cleanup() {
  local exit_code=$?
  if [[ -n "${SERVER_PID:-}" ]] && kill -0 "${SERVER_PID}" 2>/dev/null; then
    kill -TERM "${SERVER_PID}" 2>/dev/null || true
    wait "${SERVER_PID}" 2>/dev/null || true
  fi
  rm -f "${PID_FILE}"
  rm -rf "${LOCK_DIR}"
  return "${exit_code}"
}

validate_port() {
  local port_value="$1"
  if ! [[ "${port_value}" =~ ^[0-9]+$ ]] || (( port_value < 1 || port_value > 65535 )); then
    fail "WEB_PORT must be an integer in range 1..65535: ${port_value}"
  fi
}

if [[ -f "${CONFIG_FILE}" ]]; then
  load_env_file "${CONFIG_FILE}"
else
  fail "Config file not found: ${CONFIG_FILE}. Copy catalogsync.env.example to catalogsync.env first."
fi

for required_var in DB_PATH ENV_FILE WEB_HOST WEB_PORT LOG_DIR PYTHON_BIN VENV_DIR; do
  require_var "${required_var}"
done
validate_port "${WEB_PORT}"

if [[ -n "${VENV_DIR:-}" && -x "${VENV_DIR}/bin/python" ]]; then
  PYTHON_BIN="${VENV_DIR}/bin/python"
fi

if ! command -v "${PYTHON_BIN}" >/dev/null 2>&1; then
  fail "PYTHON_BIN is not executable or not found in PATH: ${PYTHON_BIN}"
fi

mkdir -p "${APP_HOME}/data" "${LOG_DIR}" "$(dirname "${DB_PATH}")" "$(dirname "${ENV_FILE}")"
export PYTHONPATH="${APP_HOME}/app${PYTHONPATH:+:${PYTHONPATH}}"
acquire_serve_lock
trap cleanup EXIT INT TERM

if [[ -f "${PID_FILE}" ]]; then
  existing_pid="$(cat "${PID_FILE}" 2>/dev/null || true)"
  if [[ -n "${existing_pid}" ]] && kill -0 "${existing_pid}" 2>/dev/null; then
    fail "Server process already running (pid=${existing_pid})"
  fi
  rm -f "${PID_FILE}"
fi

LOG_FILE="${LOG_DIR}/serve_console_$(date +%Y%m%d_%H%M%S).log"
exec > >(tee -a "${LOG_FILE}") 2>&1
echo "[serve_console.sh] logging to ${LOG_FILE}"

# Run from the deployed app directory so `python -m musicdl...` does not
# accidentally import an older checkout from the current working directory.
cd "${APP_HOME}/app"

"${PYTHON_BIN}" -m musicdl.catalogsync.cli serve \
  --db "${DB_PATH}" \
  --env-file "${ENV_FILE}" \
  --host "${WEB_HOST}" \
  --port "${WEB_PORT}" \
  "$@" &
SERVER_PID=$!
echo "${SERVER_PID}" > "${PID_FILE}"
echo "[serve_console.sh] server pid=${SERVER_PID}"
wait "${SERVER_PID}"