#!/bin/sh

# config
INTERVAL=1
REPORTER=stdout

#init
__METRICS=()

# load utils
for util in ./lib/utils/*.sh; do source $util; done

# load reporter
source ./reporters/${REPORTER}.sh
copy_function init      __r_${REPORTER}_init
copy_function report    __r_${REPORTER}_report
copy_function terminate __r_${REPORTER}_terminate
copy_function docs      __r_${REPORTER}_docs
unset -f init report terminate docs

# load metrics
for file in ./metrics/*.sh; do
  filename=$(basename $file)
  metric=${filename%.*}

  # soruce file and copy functions
  source $file
  copy_function init      __m_${metric}_init
  copy_function collect   __m_${metric}_collect
  copy_function terminate __m_${metric}_terminate
  copy_function docs      __m_${metric}_docs
  unset -f init collect terminate docs

  # register metric
  __METRICS+=($metric)
done

# init metrics
for metric in ${__METRICS[@]}; do
  if ! is_function __m_${metric}_init; then
    continue
  fi

  __m_${metric}_init
done

# print docs for metrics
echo "Available metrics:"
for metric in ${__METRICS[@]}; do
  if ! is_function __m_${metric}_docs; then
    continue
  fi

  echo "[$metric]"
  __m_${metric}_docs
  echo
done

# collect metrics
while true; do
  for metric in ${__METRICS[@]}; do
    if ! is_function __m_${metric}_collect; then
      continue
    fi

    report () {
      local result
      if [ -z $2 ]; then
        label=$metric
        result="$1"
      else
        label="$metric.$1"
        result="$2"
      fi
      __r_${REPORTER}_report $label $result
    }

    __m_${metric}_collect
  done

  sleep $INTERVAL
done

# trap 'kill $(jobs -pr)' SIGINT SIGTERM EXIT
# trap "trap - SIGTERM && kill -- -$$" SIGINT SIGTERM EXIT