#!/usr/bin/env bash

set -Eeo pipefail

file_env() {
	local var="$1"
	local fileVar="${var}_FILE"
	local def="${2:-}"
	if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
		printf >&2 'error: both %s and %s are set (but are exclusive)\n' "$var" "$fileVar"
		exit 1
	fi
	local val="$def"
	if [ "${!var:-}" ]; then
		val="${!var}"
	elif [ "${!fileVar:-}" ]; then
		val="$(< "${!fileVar}")"
	fi
	export "$var"="$val"
	unset "$fileVar"
}

docker_setup_env() {
	file_env 'PGPOOL_ADMIN_USERNAME'
	file_env 'PGPOOL_ADMIN_PASSWORD'
	file_env 'POSTGRES_PGPOOL_USERNAME'
	file_env 'POSTGRES_PGPOOL_PASSWORD'
  file_env 'POSTGRES_REPLICATOR_USERNAME'
  file_env 'POSTGRES_REPLICATOR_PASSWORD'
}

if [ "$(id -u)" = '0' ]; then
  service ssh start
  chown -R postgres /etc/pgpool2
	exec gosu postgres "$BASH_SOURCE"
fi

install --directory --owner postgres --group postgres --mode 700 /var/lib/postgresql/.ssh
cp /ssh/* /var/lib/postgresql/.ssh/
chmod 600 /var/lib/postgresql/.ssh/*

docker_setup_env

{
  printf "%s:" "$PGPOOL_ADMIN_USERNAME"
  pg_md5 "$PGPOOL_ADMIN_PASSWORD"
  printf "\n"
} > /etc/pgpool2/pcp.conf
{
  printf "localhost:9898:%s:%s\n" "$PGPOOL_ADMIN_USERNAME" "$PGPOOL_ADMIN_PASSWORD"
  printf "pgpool:9898:%s:%s\n" "$PGPOOL_ADMIN_USERNAME" "$PGPOOL_ADMIN_PASSWORD"
} > ~/.pcppass
chmod 600 /etc/pgpool2/pcp.conf ~/.pcppass
#{
#  openssl rand -base64 33
#} > ~/.pgpoolkey
#chmod 600 ~/.pgpoolkey
# pg_enc -m -k ~/.pgpoolkey -u $POSTGRES_PGPOOL_USERNAME $POSTGRES_PGPOOL_PASSWORD

{
  printf "# Backend Clustering Mode\n\n"
  printf "backend_clustering_mode = 'streaming_replication'\n"

  printf "\n# Connections\n\n"
  printf "listen_addresses        = '*'\n"
  printf "port                    = 5432\n"
  printf "unix_socket_directories = '/var/run/postgresql'\n"
  printf "unix_socket_group       = 'postgres'\n"
  printf "unix_socket_permissions = 0777\n"
  printf "pcp_port                = 9898\n"
  printf "pcp_socket_dir          = '/var/run/postgresql'\n"

  printf "\n# Backend Connections\n\n"
  IFS=':'
  n=0
  for backend in $PGPOOL_BACKEND
  do
    printf "\nbackend_hostname%d       = '%s'\n" $n $backend
    printf "backend_port%d           = 5432\n" $n
    printf "backend_data_directory%d = '/var/lib/postgresql/data'\n" $n
  ((n+=1))
  done
  unset IFS

  printf "\n# Authentication\n\n"
  printf "enable_pool_hba                = off\n"
  printf "pool_passwd                    = ''\n"
  printf "allow_clear_text_frontend_auth = on\n"

  printf "\n# Pools\n\n"
  printf "process_management_mode = 'dynamic'\n"

  printf "\n# Logs\n\n"
  printf "log_line_prefix        = '%m: %a pid %p: '\n"
  printf "log_per_node_statement = on\n"
  printf "logging_collector      = off\n"

  printf "\n# Replication Mode\n\n"

  printf "sr_check_period                = 10\n"
  printf "sr_check_user                  = %s\n" "$POSTGRES_REPLICATOR_USERNAME"
#  printf "sr_check_password             = %s\n" "$POSTGRES_REPLICATOR_PASSWORD"
  printf "sr_check_password              = ''\n"
  printf "follow_primary_command         = '/etc/pgpool2/follow_primary.sh %%d %%h %%p %%D %%m %%H %%M %%P %%r %%R'\n"
  printf "replication_mode               = off\n"
  printf "master_slave_mode              = on\n"
  printf "load_balance_mode              = on\n"
  printf "reset_query_on_pool_release    = on\n"
  printf "replicate_on_reset             = on\n"
  printf "online_recovery                = on\n"
  printf "detach_false_primary           = on\n"
  printf "failover_command               = '/etc/pgpool2/failover.sh %%d %%h %%p %%D %%m %%H %%M %%P %%r %%R %%N %%S'\n"
  printf "recovery_user                  = postgres\n"
  printf "recovery_password              = ''\n"
  printf "recovery_1st_stage_command     = recovery_1st_stage\n"
  printf "recovery_timeout               = 60\n"
  printf "client_idle_limit_in_recovery  = -1\n"
  printf "health_check_timeout           = 5\n"
  printf "health_check_period            = 5\n"
  printf "health_check_user              = %s\n" "$POSTGRES_PGPOOL_USERNAME"
#  printf "health_check_password = '%s'\n" "$PGPOOL_PASSWORD"
  printf "health_check_password          = ''\n"
  printf "statement_cache_mode           = off\n"
  printf "query_cache_mode               = off\n"

} > /etc/pgpool2/pgpool.conf

/usr/sbin/pgpool

while true
do
  echo "$(date)"
  sleep 3600
done