#!/usr/bin/env bash
# Enables the ability to launch a remote DevOps stack,
# attach the VNICs, assign the Public IP's to the VNIC's,
# or run terminate and destroy operations.
workingDir="/var/home/hyperuser/.devopsctl-service"
tsc="${workingDir}/node_modules/.bin/tsc"
tsnode="${workingDir}/node_modules/.bin/ts-node"
controlScript="devopsctl"
# For debugging
#nodemon="/usr/bin/nodemon"
devOpsServer="devops.us.hyperspire.net"
pidFile="${workingDir}/devopsctl.pid"

waitInterval=60   # These will need to be divisible -
updateInterval=30 # just *not* by zero 

networkWaitInterval=10
serverCheckInterval=60
serverLaunchWaitInterval=180
upstreamGateway="gateway.hyperspire.net"
dnsServers=("solv-11.us.hyperspire.net" "solv-22.us.hyperspire.net")

function notify {
  echo "{ status: \"${1}\", message: { ${2} } }"
  return 0
}

function croak {
  echo "{ status: \"WARNING\", message: { condition: \"${1}\" } }"
  return 0
}

function choke {
  echo "{ status: \"FAILED\", message: { error: \"${1}\" } }"
  exit 1
}

[[ $* != "start" && $* != "stop" && $* != "reload" && $* != "status" && $* != "status -l" && $* != "status l" && $* != "network" ]] && choke "Usage: ${controlScript} [ start | stop | reload | status | network ]"
cd "${workingDir}" || choke "Failed to cd ${workingDir}"

function checkNetworkStatus {
  [[ 0 == $(ping -c 1 -W 1 "$upstreamGateway" | grep -c '100%') ]] || networkDown=true
  [[ -z "$networkDown" ]] || sleep "${networkWaitInterval}"

  for ns in "${dnsServers[@]}"; do
    [[ 0 == $(ping -c 1 -W 1 "${ns}" | grep -c '100%') ]] || dnsServerDown=true
    [[ 0 != $(ping -c 1 -W 1 "${ns}" | grep -c '100%') ]] || unset dnsServerDown
    [[ -z "$dnsServerDown" ]] && networkDown=true
  done
  [[ ! $dnsServerDown && 0 == $(ping -c 1 -W 1 "${upstreamGateway}" | grep -c '100%') ]] && unset networkDown
  [[ ! $networkDown && 0 == $(ping -c 1 -W 1 "${devOpsServer}" | grep -c '100%') ]] && unset devOpsDown || devOpsDown=true
  [[ $networkDown == true ]] && croak "networkDown"
  [[ $dnsServerDown == true ]] && croak "dnsServerDown"
  notify "NETWORK" "dnsServerDown: \"${dnsServerDown}\", networkDown: \"${networkDown}\", devOpsDown: \"${devOpsDown}\""
  return 0
}

function runDevOpsStack {
  [[ -f "${pidFile}" ]] && rm "${pidFile}" &>/dev/null
  touch "${pidFile}"
  if ! echo "${1}" >"${pidFile}"; then
    croak "Failed to write PID to ${pidFile}"
  fi
  ${tsnode} "devopsctl-service.ts" /dev/null; then
    notify "SERVER" "\"${devOpsServer}\" powered off"
    sleep "${networkWaitInterval}"
  else
    croak "Failed to power off ${devOpsServer}"
  fi
  export KILL_DEVOPS_SERVER=true
  notify "TERMINATING" "KILL_DEVOPS_SERVER: \"${KILL_DEVOPS_SERVER}\""
  ${tsnode} "devopsctl-service.ts" /dev/null
  service devopsctl.service stop &>/dev/null
  systemctl enable devopsctl.service &>/dev/null
  service devopsctl.service start &>/dev/null
  return 0
}

if [[ $* == "stop" ]]; then
  if ! kill -9 "$(cat ${pidFile})" 2>/dev/null; then
    croak "$(kill -9 $(cat ${pidFile}))"
  fi
  killDevOpsServer
  while [[ $waitInterval -gt 0 ]]; do
    notify "STOPPING" "killDevOpsServer: \"Waiting $waitInterval seconds for DevOps service to stop.\""
    sleep $waitInterval
    ((waitInterval = waitInterval - updateInterval))
    continue
  done
  exit 0
fi

if [[ "reload" == "$*" ]]; then
  killDevOpsServer
  while [[ $waitInterval -gt 0 ]]; do
    notify "TERMINATING" "killDevOpsServer: \"Waiting $waitInterval seconds for DevOps service to shutdown.\""
    sleep $waitInterval
    ((waitInterval = waitInterval - updateInterval))
    continue
  done
  systemctl disable devopsctl.service &>/dev/null

  if [[ ! -f "/etc/systemd/system/devopsctl.service" || $(date '+%s' -r ${workingDir}/devopsctl.service) -gt $(date '+%s' -r /etc/systemd/system/devopsctl.service) ]]; then
    sudo cp -f "${workingDir}/devopsctl.service" "/etc/systemd/system/devopsctl.service"
  fi
  reloadDevOpsServer
  exit 0
fi

if [[ "status" == "$*" ]]; then
  journalctl -xu devopsctl.service | tail -n 16
  echo -e "\e[48;5;237m  \e[0m Showing only the latest status updates."
  echo -e "\e[48;5;237m  \e[0m Use \"${controlScript} -l\" for the full status."
fi

if [[ "status -l" == "$*" || "status l" == "$*" ]]; then
  journalctl -n 256 -rxu devopsctl.service
fi

if [[ "network" == "$*" ]]; then
  checkNetworkStatus
  # For troubleshooting any network related
  # issues that could cause the service to
  # to attempt to run more servers if it
  # presumes the server to be down when it
  # could just be the network went down.
  # notify "NETWORK" "dnsServerDown: \"${dnsServerDown}\", networkDown: \"${networkDown}\", devOpsDown: \"${devOpsDown}\""
fi

function monitorDevopsServer {
 checkNetworkStatus
  if [[ -z $networkDown && -n $devOpsDown ]]; then
    # Once network check succeeds, make sure everything is up to date before procceeding.
    runDevOpsStack "$$"
    sleep ${serverLaunchWaitInterval}
  else
    sleep ${serverCheckInterval}
    echo "{ status: \"RUNNING\", message: { dnsServerDown: \"${dnsServerDown}\", networkDown: \"${networkDown}\", devOpsDown: \"${devOpsDown}\" } }"
  fi
}

if [[ "start" == "$*" ]]; then
  checkNetworkStatus
  if [[ -z $networkDown && -n $devOpsDown ]]; then
    # Once network check succeeds, make sure everything is up to date before procceeding.
    notify "STARTING" "runDevOpsStack: \"true\""
    npm update &>/dev/null
    ${tsc} &>/dev/null
    runDevOpsStack "$$"
    sleep ${serverLaunchWaitInterval}
    while [[ $? -eq 0 ]]; do
      monitorDevopsServer
    done
  else
    while [[ $? -eq 0 ]]; do
      monitorDevopsServer
    done
  fi
fi