#!/bin/bash

set -eu -o pipefail

readonly script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
readonly task_worker="${script_dir}/../taskworker.js"

if [[ ${EUID} -ne 0 ]]; then
    echo "This script should be run as root." > /dev/stderr
    exit 1
fi

if [[ $# -eq 0 ]]; then
    echo "No arguments supplied"
    exit 1
fi

if [[ "$1" == "--check" ]]; then
    echo "OK"
    exit 0
fi

readonly task_id="$1"
readonly logfile="$2"
readonly nice="$3"
readonly memory_limit_mb="$4"

readonly service_name="box-task-${task_id}"
systemctl reset-failed "${service_name}" || true

readonly id=$(id -u $SUDO_USER)
readonly ubuntu_version=$(lsb_release -rs)

if [[ "${ubuntu_version}" == "16.04" ]]; then
    options="-p MemoryLimit=${memory_limit_mb}M --remain-after-exit"
else
    options="-p MemoryMax=${memory_limit_mb}M --pipe --wait"

    # Note: BindsTo will kill this task when the box is stopped. but will not kill this task when restarted!
    # For this reason, we have code to kill the tasks both on shutdown and startup.
    # BindsTo does not work on ubuntu 16, this means that even if box is stopped, the tasks keep running
    [[ "$BOX_ENV" == "cloudron" ]] && options="${options} -p BindsTo=box.service"
fi

# DEBUG has to be hardcoded because it is not set in the tests. --setenv is required for ubuntu 16 (-E does not work)
systemd-run --unit "${service_name}" --nice "${nice}" --uid=${id} --gid=${id} ${options} \
    --setenv HOME=${HOME} --setenv USER=${SUDO_USER} --setenv DEBUG=box:* --setenv BOX_ENV=${BOX_ENV} --setenv NODE_ENV=production \
    "${task_worker}" "${task_id}" "${logfile}"
exit_code=$?

if [[ "${ubuntu_version}" == "16.04" ]]; then
    sleep 3
    # we cannot use systemctl is-active because unit is always active until stopped with RemainAfterExit
    while [[ "$(systemctl show -p SubState ${service_name})" == *"running"* ]]; do
        echo "Waiting for service ${service_name} to finish"
        sleep 3
    done
    exit_code=$(systemctl show "${service_name}" -p ExecMainStatus | sed 's/ExecMainStatus=//g')
    systemctl stop "${service_name}" || true # because of remain-after-exit we have to deactivate the service
fi

echo "Service ${service_name} finished with exit code ${exit_code}"
exit "${exit_code}"