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

# This script extends the original entrypoint with support for adding
# a non-superuser owner to the $POSTGRES_DB database

# source vendor entrypoint
. /usr/local/bin/docker-entrypoint.sh

# create initial database
# uses environment variables for input: POSTGRES_DB
docker_setup_db() {
    if [ "$POSTGRES_DB_USER" != 'postgres' ]; then
        if [ -n "$POSTGRES_DB_PASSWORD" ]; then
            POSTGRES_DB= docker_process_sql --dbname postgres --set user="$POSTGRES_DB_USER" --set password="$POSTGRES_DB_PASSWORD" <<-'EOSQL'
                        CREATE USER :"user" WITH PASSWORD :'password' ;
                EOSQL
            echo
        else
            POSTGRES_DB= docker_process_sql --dbname postgres --set user="$POSTGRES_DB_USER" <<-'EOSQL'
                        CREATE USER :"user" ;
                EOSQL
            echo
        fi
        if [ "$POSTGRES_DB" != 'postgres' ]; then
            POSTGRES_DB= docker_process_sql --dbname postgres --set db="$POSTGRES_DB" --set user="$POSTGRES_DB_USER" <<-'EOSQL'
                        CREATE DATABASE :"db" WITH OWNER = :"user" ;
                EOSQL
            echo
        fi
    else
        if [ "$POSTGRES_DB" != 'postgres' ]; then
            POSTGRES_DB= docker_process_sql --dbname postgres --set db="$POSTGRES_DB" <<-'EOSQL'
                        CREATE DATABASE :"db" ;
                EOSQL
            echo
        fi
    fi
}

# Loads various settings that are used elsewhere in the script
# This should be called before any other functions
docker_setup_env() {
    file_env 'POSTGRES_PASSWORD'

    file_env 'POSTGRES_USER' 'postgres'
    file_env 'POSTGRES_DB' "$POSTGRES_USER"
    file_env 'POSTGRES_INITDB_ARGS'
    # default authentication method is md5
    : "${POSTGRES_HOST_AUTH_METHOD:=md5}"

    file_env 'POSTGRES_DB_USER' "$POSTGRES_USER"
    file_env 'POSTGRES_DB_PASSWORD'

    declare -g DATABASE_ALREADY_EXISTS
    # look specifically for PG_VERSION, as it is expected in the DB dir
    if [ -s "$PGDATA/PG_VERSION" ]; then
        DATABASE_ALREADY_EXISTS='true'
    fi
}

_main() {
    # if first arg looks like a flag, assume we want to run postgres server
    if [ "${1:0:1}" = '-' ]; then
        set -- postgres "$@"
    fi

    if [ "$1" = 'postgres' ] && ! _pg_want_help "$@"; then
        docker_setup_env
        # setup data directories and permissions (when run as root)
        docker_create_db_directories
        if [ "$(id -u)" = '0' ]; then
            # then restart script as postgres user
            exec gosu postgres "$BASH_SOURCE" "$@"
        fi

        # only run initialization on an empty data directory
        if [ -z "$DATABASE_ALREADY_EXISTS" ]; then
            docker_verify_minimum_env

            # check dir permissions to reduce likelihood of half-initialized database
            ls /docker-entrypoint-initdb.d/ > /dev/null

            docker_init_database_dir
            pg_setup_hba_conf

            # PGPASSWORD is required for psql when authentication is required for 'local' connections via pg_hba.conf and is otherwise harmless
            # e.g. when '--auth=md5' or '--auth-local=md5' is used in POSTGRES_INITDB_ARGS
            export PGPASSWORD="${PGPASSWORD:-$POSTGRES_PASSWORD}"
            docker_temp_server_start "$@"

            docker_setup_db
            docker_process_init_files /docker-entrypoint-initdb.d/*

            docker_temp_server_stop
            unset PGPASSWORD

            echo
            echo 'PostgreSQL init process complete; ready for start up.'
            echo
        else
            echo
            echo 'PostgreSQL Database directory appears to contain a database; Skipping initialization'
            echo
        fi
    fi

    exec "$@"
}

if ! _is_sourced; then
    _main "$@"
fi