#!/bin/bash

set -e

. /usr/share/debconf/confmodule

TALER_HOME="/var/lib/taler-exchange"

# usage: fixperm user:group perms file
function fixperm() {
  chown "$1" "$3"
  chmod "$2" "$3"
}

# usage: lncfg user home target
function lncfg() {
  local cf=$TALER_HOME/$2/.config
  if [ ! -e $cf ]; then
    mkdir $cf
    chown $(stat -L -c %u $TALER_HOME/$2):$(stat -L -c %g $TALER_HOME/$2) $cf
  fi
  ln -sf $3 $cf/taler.conf
}

case "${1}" in
configure)
  db_version 2.0

  db_get taler-exchange/eusername
  _EUSERNAME="${RET:-taler-exchange-httpd}"

  db_get taler-exchange/rsecusername
  _RSECUSERNAME="${RET:-taler-exchange-secmod-rsa}"

  db_get taler-exchange/esecusername
  _ESECUSERNAME="${RET:-taler-exchange-secmod-eddsa}"

  db_get taler-exchange/wireusername
  _WIREUSERNAME="${RET:-taler-exchange-wire}"

  db_get taler-exchange/aggrusername
  _AGGRUSERNAME="${RET:-taler-exchange-aggregator}"

  db_get taler-exchange/groupname
  _GROUPNAME="${RET:-taler-private}"

  db_get taler-exchange/dbgroupname
  _DBGROUPNAME="${RET:-taler-exchange-db}"

  db_stop

  CONFIG_FILE="/etc/default/taler-exchange"

  # Creating taler groups as needed
  if ! getent group ${_GROUPNAME} >/dev/null; then
    echo -n "Creating new Taler group ${_GROUPNAME}:"
    addgroup --quiet --system ${_GROUPNAME}
    echo " done."
  fi
  if ! getent group ${_DBGROUPNAME} >/dev/null; then
    echo -n "Creating new Taler group ${_DBGROUPNAME}:"
    addgroup --quiet --system ${_DBGROUPNAME}
    echo " done."
  fi

  # Creating taler users if needed
  if ! getent passwd ${_EUSERNAME} >/dev/null; then
    echo -n "Creating new Taler user ${_EUSERNAME}:"
    adduser --quiet --system --ingroup ${_GROUPNAME} --home ${TALER_HOME}/httpd ${_EUSERNAME}
    adduser ${_EUSERNAME} ${_DBGROUPNAME}
    echo " done."
  fi
  if ! getent passwd ${_RSECUSERNAME} >/dev/null; then
    echo -n "Creating new Taler user ${_RSECUSERNAME}:"
    adduser --quiet --system --ingroup ${_GROUPNAME} --home ${TALER_HOME}/secmod-rsa ${_RSECUSERNAME}
    echo " done."
  fi
  if ! getent passwd ${_ESECUSERNAME} >/dev/null; then
    echo -n "Creating new Taler user ${_ESECUSERNAME}:"
    adduser --quiet --system --ingroup ${_GROUPNAME} --home ${TALER_HOME}/secmod-eddsa ${_ESECUSERNAME}
    echo " done."
  fi
  if ! getent passwd ${_WIREUSERNAME} >/dev/null; then
    echo -n "Creating new Taler user ${_WIREUSERNAME}:"
    adduser --quiet --system --home ${TALER_HOME}/wire ${_WIREUSERNAME}
    adduser --quiet ${_WIREUSERNAME} ${_DBGROUPNAME}
    echo " done."
  fi
  if ! getent passwd ${_AGGRUSERNAME} >/dev/null; then
    echo -n "Creating new Taler user ${_AGGRUSERNAME}:"
    adduser --quiet --system --home ${TALER_HOME}/aggregator ${_AGGRUSERNAME}
    adduser --quiet ${_AGGRUSERNAME} ${_DBGROUPNAME}
    echo " done."
  fi

  # Writing new values to configuration file
  echo -n "Writing new configuration file:"
  CONFIG_NEW=$(tempfile)

  cat >"${CONFIG_NEW}" <<EOF
# This file controls the behaviour of the Taler init script.
# It will be parsed as a shell script.
# please do not edit by hand, use 'dpkg-reconfigure taler-exchange'.

TALER_EUSER=${_EUSERNAME}
TALER_RSECUSER=${_RSECUSERNAME}
TALER_ESECUSER=${_ESECUSERNAME}
TALER_WIREUSER=${_WIREUSERNAME}
TALER_AGGRUSER=${_AGGRUSERNAME}
TALER_GROUP=${_GROUPNAME}
EOF

  cat >"/etc/systemd/system/taler-exchange-httpd.socket" <<EOF
[Unit]
Description=Taler Exchange Socket
PartOf=taler-exchange-httpd.service

[Socket]
ListenStream=/var/lib/taler-exchange/exchange.sock
Accept=no
Service=taler-exchange-httpd.service
SocketUser=${_EUSERNAME}
SocketGroup=www-data
SocketMode=0660

[Install]
WantedBy=sockets.target
EOF

  cat >"/etc/systemd/system/taler-exchange-httpd.service" <<EOF
[Unit]
Description=GNU Taler payment system exchange REST API
AssertPathExists=/var/lib/taler-exchange/
Requires=taler-exchange-httpd.socket taler-exchange-secmod-rsa.service taler-exchange-secmod-eddsa.service
Wants=taler-exchange-wirewatch.service taler-exchange-aggregator.service taler-exchange-transfer.service
After=postgres.service network.target

[Service]
EnvironmentFile=/etc/default/taler-exchange
User=${_EUSERNAME}
Type=simple
Restart=on-failure
ExecStart=/usr/bin/taler-exchange-httpd -c /etc/taler/exchange-service-default.conf
StandardOutput=journal
StandardError=journal
PrivateTmp=no
PrivateDevices=yes
ProtectSystem=full

[Install]
WantedBy=multi-user.target
EOF

  cat >"/etc/systemd/system/taler-exchange-secmod-rsa.service" <<EOF
[Unit]
Description=GNU Taler payment system exchange RSA security module

[Service]
EnvironmentFile=/etc/default/taler-exchange
User=${_RSECUSERNAME}
Type=simple
Restart=on-failure
ExecStart=/usr/bin/taler-exchange-secmod-rsa -c /etc/taler/exchange-service-default.conf
StandardOutput=journal
StandardError=journal
PrivateTmp=no
PrivateDevices=yes
ProtectSystem=full

EOF
  cat >"/etc/systemd/system/taler-exchange-secmod-eddsa.service" <<EOF
[Unit]
Description=GNU Taler payment system exchange EdDSA security module

[Service]
EnvironmentFile=/etc/default/taler-exchange
User=${_ESECUSERNAME}
Type=simple
Restart=on-failure
ExecStart=/usr/bin/taler-exchange-secmod-eddsa -c /etc/taler/exchange-service-default.conf
StandardOutput=journal
StandardError=journal
PrivateTmp=no
PrivateDevices=yes
ProtectSystem=full

EOF
  cat >"/etc/systemd/system/taler-exchange-wirewatch.service" <<EOF
[Unit]
Description=GNU Taler payment system exchange wirewatch service
After=network.target

[Service]
EnvironmentFile=/etc/default/taler-exchange
User=${_WIREUSERNAME}
Type=simple
Restart=on-failure
ExecStart=/usr/bin/taler-exchange-wirewatch -c /etc/taler/exchange-service-wire.conf
StandardOutput=journal
StandardError=journal
PrivateTmp=yes
PrivateDevices=yes
ProtectSystem=full


EOF
  cat >"/etc/systemd/system/taler-exchange-transfer.service" <<EOF
[Unit]
Description=GNU Taler payment system exchange transfer service
After=network.target

[Service]
EnvironmentFile=/etc/default/taler-exchange
User=${_WIREUSERNAME}
Type=simple
Restart=on-failure
ExecStart=/usr/bin/taler-exchange-wirewatch -c /etc/taler/exchange-service-wire.conf
StandardOutput=journal
StandardError=journal
PrivateTmp=yes
PrivateDevices=yes
ProtectSystem=full

EOF
  cat >"/etc/systemd/system/taler-exchange-aggregator.service" <<EOF
[Unit]
Description=GNU Taler payment system exchange aggregator service

[Service]
EnvironmentFile=/etc/default/taler-exchange
User=${_AGGRUSERNAME}
Type=simple
Restart=on-failure
ExecStart=/usr/bin/taler-exchange-aggregator -c /etc/taler/exchange-service-default.conf
StandardOutput=journal
StandardError=journal
PrivateTmp=yes
PrivateDevices=yes
ProtectSystem=full


EOF

  cp -f "${CONFIG_NEW}" "${CONFIG_FILE}"
  rm -f "${CONFIG_NEW}"
  echo " done."

  echo -n "Setting up system services "

  mkdir -p /var/lib/taler-exchange/tmp
  chown root:${_GROUPNAME} /var/lib/taler-exchange/tmp
  chmod 770 /var/lib/taler-exchange/tmp
  chmod +s /var/lib/taler-exchange/tmp

  fixperm ${_WIREUSERNAME}:root 460 /etc/taler/exchange-wire-gateway.conf
  fixperm root:${_DBGROUPNAME} 640 /etc/taler/exchange-db.conf

  systemctl daemon-reload >/dev/null 2>&1 || true

  echo "done."

  echo -n "Linking config files"
  lncfg ${_EUSERNAME} httpd /etc/taler/exchange-service-default.conf
  lncfg ${_RSECUSERNAME} secmod-rsa /etc/taler/exchange-service-default.conf
  lncfg ${_ESECUSERNAME} secmod-eddsa /etc/taler/exchange-service-default.conf
  lncfg ${_AGGRUSERNAME} aggregator /etc/taler/exchange-service-default.conf
  lncfg ${_WIREUSERNAME} wire /etc/taler/exchange-service-wire.conf
  echo " done"

  # Cleaning
  echo "All done."
  ;;

abort-upgrade | abort-remove | abort-deconfigure) ;;

*)
  echo "postinst called with unknown argument \`${1}'" >&2
  exit 1
  ;;
esac

#DEBHELPER#

exit 0