#!/usr/bin/env bash

set -euo pipefail

#############
# VARIABLES #
#############

basedir=$(dirname "$0")
no_header="ceph-docker-common" # pipe separated list of roles with no header, MUST end with '$', e.g: 'foo$|bar$'
merge_in_all="ceph-common$|ceph-docker-common$" # pipe separated list of roles you want to merge in all.yml.sample, MUST end with '$', e.g: 'foo$|bar$'


#############
# FUNCTIONS #
#############

populate_header () {
  cat <<EOF > "$basedir"/group_vars/"$output"
---
# Variables here are applicable to all host groups NOT roles

# This sample file generated by $(basename "$0")

# Dummy variable to avoid error because ansible does not recognize the
# file as a good configuration file when no variable in it.
dummy:

EOF
}

generate_group_vars_file () {
  if [ "$(uname)" == "Darwin" ]; then
    sed '/^---/d; s/^\([A-Za-z[:space:]]\)/#\1/' \
      "$defaults" >> "$basedir"/group_vars/"$output"
    echo >> "$basedir"/group_vars/"$output"
  elif [ "$(uname -s)" == "Linux" ]; then
    sed '/^---/d; s/^\([A-Za-z[:space:]].\+\)/#\1/' \
      "$defaults" >> "$basedir"/group_vars/"$output"
    echo >> "$basedir"/group_vars/"$output"
  else
    echo "Unsupported platform"
    exit 1
  fi
}


########
# MAIN #
########

for role in "$basedir"/roles/ceph-*; do
  rolename=$(basename "$role")

  if echo "$rolename" | grep -qE "$merge_in_all"; then
    output="all.yml.sample"
  elif [[ $rolename == "ceph-agent" ]]; then
    output="agent.yml.sample"
  elif [[ $rolename == "ceph-fetch-keys" ]]; then
    output="ceph-fetch-keys.yml.sample"
  else
    output="${rolename:5}s.yml.sample"
  fi


  # Do not re-regenerate the header for certain roles
  # since we merge them in all.yml.sample
  if ! echo "$rolename" | grep -qE "$no_header"; then
    populate_header
  fi

  defaults="$role"/defaults/main.yml
  if [[ ! -f $defaults ]]; then
    continue
  fi

  generate_group_vars_file
done