# -*- sh-basic-offset: 2 indent-tabs-mode: nil -*-

declare -a _positional_args
declare _dry_run=no
declare _state_file
declare _task_file
declare _org

while [[ $# -gt 0 ]]; do
  case $1 in
    -n|--dry-run)
      _dry_run="yes"
      shift # past argument
      ;;
    -s|--state)
      if [[ -z "${2:-}" ]] ; then
        echo "$1 takes one argument"
        exit 2
      fi

      _state_file="$2"
      shift # past argument
      shift # past value
      ;;
    -f|--file)
      if [[ -z "${2:-}" ]] ; then
        echo "$1 takes one argument"
        exit 2
      fi

      _task_file="$2"
      shift # past argument
      shift # past value
      ;;
    -o|--org)
      if [[ -z "${2:-}" ]] ; then
        echo "$1 takes one argument"
        exit 2
      fi

      _org="$2"
      shift # past argument
      shift # past value
      ;;
    --*|-*)
      echo "Unknown option $1"
      exit 1
      ;;
    *)
      _positional_args+=("$1") # save positional arg
      shift # past argument
      ;;
  esac
done

set -- "${_positional_args[@]}"

if [[ -z "${_state_file:-}" ]] ; then
  echo "-s|--state must be specified"
  exit 2
fi

if [[ -z "${_task_file:-}" ]] ; then
  echo "-f|--file must be specified"
  exit 2
fi

if ! [[ -f "$_task_file" ]] ; then
  echo "$_task_file must exist and be writable"
  exit 2
fi

if ! [[ -w "$_state_file" ]] ; then
  touch "$_state_file" || ( echo "Couldn't create state file" ; exit 2 )
  echo "[]" > "$_state_file"
fi

if [[ -z "${_org:-}" ]] ; then
  echo "-o|--org must be specified"
  exit 2
fi

if [[ -z "${INFLUX_HOST:-}" ]] ; then
  echo "INFLUX_HOST must be set"
  exit 2
fi

if [[ -z "${INFLUX_TOKEN:-}" ]] ; then
  echo "INFLUX_TOKEN must be set"
  exit 2
fi


if ! influx task list --org "$_org" >/dev/null 2>&1 ; then
  echo "Failed to establish connection to InfuxDB"
  exit 2
fi

declare -a _tasks_to_remove
declare -a _tasks_to_add
declare -a _tasks_to_update

mapfile -t _tasks_to_remove < <(comm -23 <(jq -r '.[].name' < "$_state_file" | sort) <(jq -r '.[].name' < "$_task_file" | sort))
mapfile -t _tasks_to_add < <(comm -13 <(jq -r '.[].name' < "$_state_file" | sort) <(jq -r '.[].name' < "$_task_file" | sort))
mapfile -t _tasks_to_update < <(comm -12 <(jq -r '.[].name' < "$_state_file" | sort) <(jq -r '.[].name' < "$_task_file" | sort))

function task_key_by_name() {
  _file="$1"
  _task="$2"
  _key="$3"

  # shellcheck disable=SC2086 # Intended splitting of JQ_OPTS
  jq ${JQ_OPTS:-} '.[] | select(.name == "'"$_task"'") | .'"$_key" < "$_file"
}

function prepend_if_not_null() {
  _prepend=$1
  _input=$(cat)

  if [[ "$_input" != "null" ]] ; then
    echo "$_prepend $_input"
  fi
}

function generate_flux_file() {
  _task="$1"

  cat <<EOF
option task = {
  name: $(task_key_by_name "$_task_file" "$task" "name")
  $(task_key_by_name "$_task_file" "$task" "cron" | prepend_if_not_null ", cron: ")
  $(JQ_OPTS="-r" task_key_by_name "$_task_file" "$task" "every" | prepend_if_not_null ", every: ")
}

$(cat "$(JQ_OPTS="-r" task_key_by_name "$_task_file" "$task" "flux_file")")

EOF
}

function task_delete() {
  _id="$1"

  influx task delete --id "$_id"
}

function task_create() {
  _flux_file="$1"

  influx task create --org "$_org" --file <(cat "$_flux_file")
}

function task_update() {
  _task="$1"
  _flux_file="$2"

  influx task update --id "$(JQ_OPTS="-r" task_key_by_name "$_state_file" "$_task" "id")" --file "$_flux_file"
}

for task in "${_tasks_to_remove[@]}" ; do
  if [[ "$_dry_run" == "no" ]] ; then
    echo "Removing $task"

    task_delete "$(JQ_OPTS="-r" task_key_by_name "$_state_file" "$task" "id")"
  else
    echo "Would remove $task"
  fi
done

for task in "${_tasks_to_add[@]}" ; do
  if [[ "$_dry_run" == "no" ]] ; then
    echo "Adding $task"
    _flux_file=$(generate_flux_file "$task")

    task_create <(cat <<<"$_flux_file")
  else
    echo "Would add $task"
  fi
done

for task in "${_tasks_to_update[@]}" ; do
  if [[ "$_dry_run" == "no" ]] ; then
    echo "Updating $task"
    _flux_file=$(generate_flux_file "$task")

    _output="$(task_update "$task" <(cat <<<"$_flux_file") 2>&1)"

    if [[ "$?" == "1" ]] && [[ "$_output" == *"404"* ]] ; then
      echo "Failed to update, creating: $_output"
      task_create <(cat <<<"$_flux_file")
    fi
  else
    echo "Would update $task"
  fi
done

_current_state=$(influx task list --org "$_org" --json)

if [[ "$_dry_run" == "no" ]] ; then
  echo "Saving new state"
  cat "$_task_file" <(cat <<<"$_current_state") | jq -s '[.[0] as $new | .[1] as $old | $old[] | select(.name | IN($new[].name))]' > "$_state_file"
fi