#!/usr/bin/env bash
set -Eeo pipefail

# usage: file_env VAR [DEFAULT]
file_env() {
	local var="$1"
	local fileVar="${var}_FILE"
	local def="${2:-}"
	if [ "${!var:-}" ] && [ "${!fileVar:-}" ]; then
		echo >&2 "error: both $var and $fileVar are set (but are exclusive)"
		exit 1
	fi
	local val="$def"
	if [ "${!var:-}" ]; then
		val="${!var}"
	elif [ "${!fileVar:-}" ]; then
		val="$(< "${!fileVar}")"
	fi
	export "$var"="$val"
	unset "$fileVar"
}

# Setup environment variables
file_env 'POSTGRES_PASSWORD'
file_env 'POSTGRES_USER' 'postgres'
file_env 'POSTGRES_DB' "$POSTGRES_USER"
file_env 'POSTGRES_INITDB_ARGS'

# Initialize database if needed
if [ ! -s "$PGDATA/PG_VERSION" ]; then
	echo "Initializing database..."
	
	/usr/lib/postgresql/16/bin/initdb --username="$POSTGRES_USER" --pwfile=<(echo "$POSTGRES_PASSWORD") $POSTGRES_INITDB_ARGS
	
	# Configure pg_hba.conf for network access
	{
		echo
		echo "host all all all scram-sha-256"
	} >> "$PGDATA/pg_hba.conf"
	
	# Start temporary server for setup
	/usr/lib/postgresql/16/bin/pg_ctl -D "$PGDATA" -w start -o "-c listen_addresses=''" || exit 1
	
	# Create database if needed
	if [ "$POSTGRES_DB" != 'postgres' ]; then
		/usr/lib/postgresql/16/bin/psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname postgres <<-EOSQL
			CREATE DATABASE "$POSTGRES_DB";
		EOSQL
	fi
	
	# Run init scripts if present
	if [ -d /docker-entrypoint-initdb.d ]; then
		for f in /docker-entrypoint-initdb.d/*; do
			case "$f" in
				*.sh)     echo "$0: running $f"; . "$f" ;;
				*.sql)    echo "$0: running $f"; /usr/lib/postgresql/16/bin/psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" < "$f" ;;
				*)        echo "$0: ignoring $f" ;;
			esac
		done
	fi
	
	# Stop temporary server
	/usr/lib/postgresql/16/bin/pg_ctl -D "$PGDATA" -m fast -w stop
	
	echo "Database initialization complete."
fi

# Start PostgreSQL
exec /usr/lib/postgresql/16/bin/postgres "$@"