#!/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 'POSTGRES_PASSWORD'
	file_env 'POSTGRES_REPLICATOR_USERNAME'
	file_env 'POSTGRES_REPLICATOR_PASSWORD'
	file_env 'POSTGRES_PGPOOL_USERNAME'
	file_env 'POSTGRES_PGPOOL_PASSWORD'
}

docker_temp_server_start() {
  NOTIFY_SOCKET= \
  PGUSER="postgres" \
  pg_ctl -D "${PGDATA}" \
  	-o "-c listen_addresses='' -p 5432" \
   	-w start
}

docker_temp_server_stop() {
	PGUSER="postgres" \
	pg_ctl -D "${PGDATA}" -m fast -w stop
}

pg_setup_conf() {
	{
		printf "\n"
    printf "archive_command          = '/bin/true'\n"
    printf "archive_mode             = on\n"
    printf "hot_standby              = on\n"
    printf "max_replication_slots    = 10\n"
    printf "max_wal_senders          = 10\n"
    printf "wal_compression          = on\n"
    printf "wal_log_hints            = on\n"
    if [[ -n $POSTGRES_MAX_CONNECTIONS ]]; then
      printf "\nmax_connections = '%s'\n" "$POSTGRES_MAX_CONNECTIONS"
    fi
	} >> "$PGDATA/postgresql.conf"
}

pg_setup_hba_conf() {
	{
		printf '\n'
    printf 'local  all  all  trust\n'
    if [[ -n $POSTGRES_REPLICATOR_USERNAME ]]; then
      printf 'local  replication  %s  trust\n' "$POSTGRES_REPLICATOR_USERNAME"
      printf 'host  replication  %s  127.0.0.1/32  trust\n' "$POSTGRES_REPLICATOR_USERNAME"
      printf 'host  replication  %s  %s  trust\n' "$POSTGRES_REPLICATOR_USERNAME" "${POSTGRES_NETWORK:-100.64.0.0/10}"
    fi
    if [[ -n $POSTGRES_PGPOOL_USERNAME ]]; then
      printf 'local  replication  %s  trust\n' "$POSTGRES_PGPOOL_USERNAME"
      printf 'host  replication  %s  127.0.0.1/32  trust\n' "$POSTGRES_PGPOOL_USERNAME"
      printf 'host  replication  %s  %s  trust\n' "$POSTGRES_PGPOOL_USERNAME" "${POSTGRES_NETWORK:-100.64.0.0/10}"
    fi
    printf '\n'
    printf 'host  all all all scram-sha-256\n'
	} >> "$PGDATA/pg_hba.conf"
}

if [ "$(id -u)" = '0' ]; then
	exec gosu postgres "$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

if [[ ! -s "$PGDATA/PG_VERSION" ]]; then
  if [[ -z $POSTGRES_UPSTREAM ]] || [[ -z $POSTGRES_REPLICATOR_USERNAME ]]; then
    initdb --username=postgres --pwfile=<(printf "%s\n" "${POSTGRES_PASSWORD}")
    pg_setup_conf
    pg_setup_hba_conf
    if [[ -n $POSTGRES_REPLICATOR_USERNAME ]] || [[ -n $POSTGRES_PGPOOL_USERNAME ]]; then
      export PGPASSWORD="$POSTGRES_PASSWORD"
      docker_temp_server_start
      if [[ -n $POSTGRES_REPLICATOR_USERNAME ]]; then
        psql -c "CREATE USER ${POSTGRES_REPLICATOR_USERNAME} WITH REPLICATION LOGIN ENCRYPTED PASSWORD '${POSTGRES_REPLICATOR_PASSWORD}';"
      fi
      if [[ -n $POSTGRES_PGPOOL_USERNAME ]]; then
        psql -c "CREATE USER ${POSTGRES_PGPOOL_USERNAME} WITH LOGIN ENCRYPTED PASSWORD '${POSTGRES_PGPOOL_PASSWORD}';"
        psql -c "CREATE EXTENSION pgpool_recovery;" template1
      fi
      docker_temp_server_stop
  		unset PGPASSWORD
    fi
  else
    until pg_basebackup -h "${POSTGRES_UPSTREAM}" -U "${POSTGRES_REPLICATOR_USERNAME}" -D "${PGDATA}" -Fp -Xs -R &> /dev/null
    do
      echo "Upstream host not ready. Waiting for 5 minutes..."
      sleep 300
    done
  fi
fi

sudo service ssh start
postgres