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

# usage: file_env VAR [DEFAULT]
#    ie: file_env 'XYZ_DB_PASSWORD' 'example'
# (will allow for "$XYZ_DB_PASSWORD_FILE" to fill in the value of
#  "$XYZ_DB_PASSWORD" from a file, especially for Docker's secrets feature)

set -x

export GAUSSHOME=/usr/local/mogdb
export PATH=$GAUSSHOME/bin:$PATH
export LD_LIBRARY_PATH=$GAUSSHOME/lib:$LD_LIBRARY_PATH
export LANG=en_US.UTF-8

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"
}

# check to see if this file is being run or sourced from another script
_is_sourced() {
  [ "${#FUNCNAME[@]}" -ge 2 ] &&
    [ "${FUNCNAME[0]}" = '_is_sourced' ] &&
    [ "${FUNCNAME[1]}" = 'source' ]
}

# used to create initial mogdb directories and if run as root, ensure ownership belong to the omm user
docker_create_db_directories() {
  local user
  user="$(id -u)"

  mkdir -p "$PGDATA"
  chmod 700 "$PGDATA"

  # ignore failure since it will be fine when using the image provided directory;
  mkdir -p /var/run/mogdb || :
  chmod 775 /var/run/mogdb || :

  # Create the transaction log directory before initdb is run so the directory is owned by the correct user
  if [ -n "$POSTGRES_INITDB_XLOGDIR" ]; then
    mkdir -p "$POSTGRES_INITDB_XLOGDIR"
    if [ "$user" = '0' ]; then
      find "$POSTGRES_INITDB_XLOGDIR" \! -user postgres -exec chown postgres '{}' +
    fi
    chmod 700 "$POSTGRES_INITDB_XLOGDIR"
  fi

  # allow the container to be started with `--user`
  if [ "$user" = '0' ]; then
    find "$PGDATA" \! -user omm -exec chown omm '{}' +
    find /var/run/mogdb \! -user omm -exec chown omm '{}' +
  fi
}

# initialize empty PGDATA directory with new database via 'initdb'
# arguments to `initdb` can be passed via POSTGRES_INITDB_ARGS or as arguments to this function
# `initdb` automatically creates the "postgres", "template0", and "template1" dbnames
# this is also where the database user is created, specified by `GS_USER` env
docker_init_database_dir() {
  # "initdb" is particular about the current user existing in "/etc/passwd", so we use "nss_wrapper" to fake that if necessary
  if ! getent passwd "$(id -u)" &>/dev/null && [ -e /usr/lib/libnss_wrapper.so ]; then
    export LD_PRELOAD='/usr/lib/libnss_wrapper.so'
    export NSS_WRAPPER_PASSWD="$(mktemp)"
    export NSS_WRAPPER_GROUP="$(mktemp)"
    echo "postgres:x:$(id -u):$(id -g):PostgreSQL:$PGDATA:/bin/false" >"$NSS_WRAPPER_PASSWD"
    echo "postgres:x:$(id -g):" >"$NSS_WRAPPER_GROUP"
  fi

  if [ -n "$POSTGRES_INITDB_XLOGDIR" ]; then
    set -- --xlogdir "$POSTGRES_INITDB_XLOGDIR" "$@"
  fi

  cmdbase="gs_initdb --pwfile=<(echo \"$GS_PASSWORD\")"

  if [ -n "$GS_NODENAME" ]; then
    cmdbase="$cmdbase --nodename=$GS_NODENAME"
  else
    cmdbase="$cmdbase --nodename=mogdb"
  fi

  if [ -n "$ENCODING" ]; then
    cmdbase="$cmdbase --encoding=$ENCODING"
  else
    cmdbase="$cmdbase --encoding=UTF-8"
  fi

  if [ -n "$LOCALE" ]; then
    cmdbase="$cmdbase --locale=$LOCALE"
  else
    cmdbase="$cmdbase --no-locale"
  fi

  if [ -n "$DBCOMPATIBILITY" ]; then
    cmdbase="$cmdbase --dbcompatibility=$DBCOMPATIBILITY"
  else
    cmdbase="$cmdbase --dbcompatibility=PG"
  fi
  if [ -n "$GS_USER" ]; then
    cmdbase="$cmdbase --user=$GS_USER"
  fi

  cmdbase="$cmdbase -D $PGDATA"

  eval "$cmdbase"

  # unset/cleanup "nss_wrapper" bits
  if [ "${LD_PRELOAD:-}" = '/usr/lib/libnss_wrapper.so' ]; then
    rm -f "$NSS_WRAPPER_PASSWD" "$NSS_WRAPPER_GROUP"
    unset LD_PRELOAD NSS_WRAPPER_PASSWD NSS_WRAPPER_GROUP
  fi
}

# print large warning if GS_PASSWORD is long
# error if both GS_PASSWORD is empty and GS_HOST_AUTH_METHOD is not 'trust'
# print large warning if GS_HOST_AUTH_METHOD is set to 'trust'
# assumes database is not set up, ie: [ -z "$DATABASE_ALREADY_EXISTS" ]
docker_verify_minimum_env() {
  # check password first so we can output the warning before postgres
  # messes it up
  if [[ "$GS_PASSWORD" =~ ^(.{8,}).*$ ]] && [[ "$GS_PASSWORD" =~ ^(.*[a-z]+).*$ ]] && [[ "$GS_PASSWORD" =~ ^(.*[A-Z]).*$ ]] && [[ "$GS_PASSWORD" =~ ^(.*[0-9]).*$ ]] && [[ "$GS_PASSWORD" =~ [^a-zA-Z0-9] ]]; then
    cat >&2 <<-'EOWARN'

      Message: The supplied GS_PASSWORD is meet requirements.

EOWARN
  else
    cat >&2 <<-'EOWARN'
      Error: The supplied GS_PASSWORD is not meet requirements.
             Please Check if the password contains uppercase, lowercase, numbers, special characters, and password length(8).
             At least one uppercase, lowercase, numeric, special character.
             Example: Enmo@123
EOWARN
    # exit 1
  fi
  if [ -z "$GS_PASSWORD" ] && [ 'trust' != "$GS_HOST_AUTH_METHOD" ]; then
    # The - option suppresses leading tabs but *not* spaces. :)
    cat >&2 <<-'EOE'
      Error: Database is uninitialized and superuser password is not specified.
             You must specify GS_PASSWORD to a non-empty value for the
             superuser. For example, "-e GS_PASSWORD=password" on "docker run".

             You may also use "GS_HOST_AUTH_METHOD=trust" to allow all
             connections without a password. This is *not* recommended.

EOE
    exit 1
  fi
  if [ 'trust' = "$GS_HOST_AUTH_METHOD" ]; then
    cat >&2 <<-'EOWARN'
                        ********************************************************************************
                        WARNING: GS_HOST_AUTH_METHOD has been set to "trust". This will allow
                                 anyone with access to the mogdb port to access your database without
                                 a password, even if GS_PASSWORD is set.
                                 It is not recommended to use GS_HOST_AUTH_METHOD=trust. Replace
                                 it with "-e GS_PASSWORD=password" instead to set a password in
                                 "docker run".
                        ********************************************************************************
EOWARN
  fi
}

# usage: docker_process_init_files [file [file [...]]]
#    ie: docker_process_init_files /always-initdb.d/*
# process initializer files, based on file extensions and permissions
docker_process_init_files() {
  # gsql here for backwards compatiblilty "${gsql[@]}"
  gsql=(docker_process_sql)

  echo
  local f
  for f; do
    case "$f" in
    *.sh)
      if [ -x "$f" ]; then
        echo "$0: running $f"
        "$f"
      else
        echo "$0: sourcing $f"
        . "$f"
      fi
      ;;
    *.sql)
      echo "$0: running $f"
      docker_process_sql -f "$f"
      echo
      ;;
    *.sql.gz)
      echo "$0: running $f"
      gunzip -c "$f" | docker_process_sql
      echo
      ;;
    *.sql.xz)
      echo "$0: running $f"
      xzcat "$f" | docker_process_sql
      echo
      ;;
    *) echo "$0: ignoring $f" ;;
    esac
    echo
  done
}

# Execute sql script, passed via stdin (or -f flag of pqsl)
# usage: docker_process_sql [gsql-cli-args]
#    ie: docker_process_sql --dbname=mydb <<<'INSERT ...'
#    ie: docker_process_sql -f my-file.sql
#    ie: docker_process_sql <my-file.sql
docker_process_sql() {
  local query_runner=(gsql -v ON_ERROR_STOP=1 --username "$GS_USER" --password "$GS_PASSWORD")
  if [ -n "$GS_DB" ]; then
    query_runner+=(--dbname "$GS_DB")
  fi

  echo "Execute SQL: ${query_runner[@]} $@"
  "${query_runner[@]}" "$@"
}

# create initial database
# uses environment variables for input: GS_DB
docker_setup_db() {
  echo "GS_DB = $GS_DB"
  if [ "$GS_DB" != 'postgres' ]; then
    GS_DB= docker_process_sql --dbname postgres --set db="$GS_DB" --set passwd="$GS_PASSWORD" <<-'EOSQL'
                        CREATE DATABASE :"db" ;

EOSQL
    echo
  fi
}

docker_setup_user() {
  if [ -n "$GS_USERNAME" ]; then
    GS_DB= docker_process_sql --dbname postgres --set db="$GS_DB" --set passwd="$GS_PASSWORD" --set user="$GS_USERNAME" <<-'EOSQL'
                        create user :"user" with login password :"passwd" sysadmin opradmin monadmin;

EOSQL
    echo "default user is $GS_USERNAME"
  else
    echo "default user is mogdb"
  fi
}

docker_setup_rep_user() {
  if [ -n "$SERVER_MODE" ] && [ "$SERVER_MODE" = "primary" ]; then
    GS_DB= docker_process_sql --dbname postgres --set passwd="${REPUSER_PASSWORD}" --set user="repuser" <<-'EOSQL'
                        create user :"user" SYSADMIN REPLICATION password :"passwd" ;
EOSQL
  else
    echo " default no repuser created"
  fi
}

# Loads various settings that are used elsewhere in the script
# This should be called before any other functions
docker_setup_env() {
  export GS_USER=omm
  file_env 'POSTGRES_INITDB_ARGS'
  # default authentication method is md5
  : "${GS_HOST_AUTH_METHOD:=md5}"

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

  declare -g REPUSER_PASSWORD
  if [ -z "${REPUSER_PASSWORD}" ]; then
    REPUSER_PASSWORD="RepUser@2020"
  fi
}

# append GS_HOST_AUTH_METHOD to pg_hba.conf for "host" connections
mogdb_setup_hba_conf() {
 if [ -e /tmp/pg_hba.conf ]; then
   cat /tmp/pg_hba.conf >"$PGDATA/pg_hba.conf"
   echo "Successfully replaced $PGDATA/pg_hba.conf with /tmp/pg_hba.conf."
 fi

  {
    echo
    if [ 'trust' = "$GS_HOST_AUTH_METHOD" ]; then
      echo '# warning trust is enabled for all connections'
    fi
    echo "host all all 0.0.0.0/0 $GS_HOST_AUTH_METHOD"
    echo "host replication $GS_USER 0.0.0.0/0 md5"
    echo "host replication $GS_USERNAME 0.0.0.0/0 md5"
    if [ -n "$SERVER_MODE" ]; then
      echo "host replication repuser $OG_SUBNET trust"
    fi
  } >>"$PGDATA/pg_hba.conf"
}

# append parameter to postgres.conf for connections
mogdb_setup_postgresql_conf() {
  if [ -e /tmp/postgresql.conf ];then
    cat /tmp/postgresql.conf >"$PGDATA/postgresql.conf"
    echo "Successfully replaced $PGDATA/postgresql.conf with /tmp/postgresql.conf."
  fi

  {
    echo
    echo "password_encryption_type = 1"
    echo "wal_level = logical"
    echo "unix_socket_directory = '$PGHOST'"

    if [ -n "$GS_PORT" ]; then
      echo "port = $GS_PORT"
    fi

    if [ -n "$SERVER_MODE" ]; then
      echo "listen_addresses = '0.0.0.0'"
      echo "most_available_sync = on"
      echo "remote_read_mode = non_authentication"
      echo "pgxc_node_name = '$NODE_NAME'"
      echo -e "$REPL_CONN_INFO"
      if [ -e /tmp/replconninfo.conf  ];then
        cat /tmp/replconninfo.conf
      fi

      if [ -n "$SYNCHRONOUS_STANDBY_NAMES" ]; then
        echo "synchronous_standby_names=$SYNCHRONOUS_STANDBY_NAMES"
      fi
    else
      echo "listen_addresses = '*'"
    fi

    if [ -n "$OTHER_PG_CONF" ]; then
      echo -e "$OTHER_PG_CONF"
    fi

  } >>"$PGDATA/postgresql.conf"
}

mogdb_setup_mot_conf() {
  echo "enable_numa = false" >>"$PGDATA/mot.conf"
}

# start socket-only postgresql server for setting up or running scripts
# all arguments will be passed along as arguments to `postgres` (via pg_ctl)
docker_temp_server_start() {
  if [ "$1" = 'mogdb' ]; then
    shift
  fi

  # internal start of server in order to allow setup using gsql client
  # does not listen on external TCP/IP and waits until start finishes
  set -- "$@" -c listen_addresses='127.0.0.1' -p "${PGPORT:-5432}"

  PGUSER="${PGUSER:-$GS_USER}" \
    gs_ctl -D "$PGDATA" \
    -o "$(printf '%q ' "$@")" \
    -w start
}

# stop postgresql server after done setting up user and running scripts
docker_temp_server_stop() {
  PGUSER="${PGUSER:-postgres}" \
    gs_ctl -D "$PGDATA" -m fast -w stop
}

docker_slave_full_backup() {
  gs_ctl build -D "$PGDATA" -b full
}

# check arguments for an option that would cause mogdb to stop
# return true if there is one

_mogdb_want_help() {
  local arg
  count=1
  for arg; do
    case "$arg" in
    # postgres --help | grep 'then exit'
    # leaving out -C on purpose since it always fails and is unhelpful:
    # postgres: could not access the server configuration file "/var/lib/postgresql/data/postgresql.conf": No such file or directory
    -'?' | --help | --describe-config | -V | --version)
      return 0
      ;;
    esac
    if [ "$arg" == "-M" ]; then
      SERVER_MODE=${@:$count+1:1}
      echo "mogdb DB SERVER_MODE = $SERVER_MODE"
      shift
    fi
    count=$(($count + 1))
  done
  return 1
}

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

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

      # PGPASSWORD is required for gsql 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="${PGPASSWORD:-$GS_PASSWORD}"
      docker_temp_server_start "$@"
      if [ -z "$SERVER_MODE" ] || [ "$SERVER_MODE" = "primary" ]; then
        docker_setup_db
        docker_setup_user
        docker_setup_rep_user
        docker_process_init_files /docker-entrypoint-initdb.d/*
      fi

      if [ -n "$SERVER_MODE" ] && [ "$SERVER_MODE" != "primary" ]; then
        docker_slave_full_backup
      fi
      docker_temp_server_stop
      unset PGPASSWORD

      echo
      echo 'mogdb  init process complete; ready for start up.'
      echo
    else
      if [ -n "$REPL_CONN_INFO" ]; then
        gs_guc set -D "$PGDATA" -c "$REPL_CONN_INFO"
      fi

      if [ -e /tmp/replconninfo.conf  ];then
        while read -r replconninfo_line;do
          gs_guc set -D "$PGDATA" -c "$replconninfo_line"
        done < /tmp/replconninfo.conf
      fi

      echo
      echo 'mogdb Database directory appears to contain a database; Skipping initialization'
      echo
    fi
  fi
  exec "$@"
}

if ! _is_sourced; then
  _main "$@"
fi
