#!/bin/sh
# Copyright (C) 2013 g10 Code GmbH
#
# This file is free software; as a special exception the author gives
# unlimited permission to copy and/or distribute it, with or without
# modifications, as long as this notice is preserved.  This file is
# distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY, to the extent permitted by law; without even the implied
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

if [ -z "$(command -v gpg-connect-agent)" ]; then
   echo "gpg-agent not installed and thus not started" >&2
   exit 0;
fi

GPG_AGENT_INFO=
export GPG_AGENT_INFO
GPG_AGENT=$(which gpg-agent)

token=$(echo "gpgme-$(pwd)" | tr ' ' '_')

if [ "$1" = "--stop" ]; then
  if [ "$(gpg-connect-agent --no-autostart getval\ $token /bye 2>/dev/null | head -1)" \
        != "D set" ]; then
    echo "gpg-agent not running" >&2
    exit 0
  fi
  echo "stopping gpg-agent " >&2
  gpg-connect-agent KILLAGENT /bye >/dev/null 2>&1
  exit 0
fi

# Update 'agent-program' in the configuration files to make sure we
# will always start exactly this agent again if we ever need to.
for F in gpg.conf gpgsm.conf
do
  if test -f "$GNUPGHOME/$F"
  then
      cat "$GNUPGHOME/$F" > "$GNUPGHOME/$F~"
      sed -e "s#^agent-program.*#agent-program ${GPG_AGENT}|--debug-quick-random#" \
          >"$GNUPGHOME/$F" <"$GNUPGHOME/$F~"
      rm -f "$GNUPGHOME/$F~"
  fi
done

if [ "$(gpg-connect-agent --no-autostart getval\ $token /bye 2>/dev/null | head -1)" \
      = "D set" ]; then
  echo "gpg-agent already running" >&2
  exit 0
fi

echo "starting gpg-agent.." >&2

# GnuPG prior to 2.1.12 needs --allow-loopback-pinentry for the
# loopback entry to work.  Old versions do not understand this though,
# so we need to be careful.
if "$GPG_AGENT" --gpgconf-test --allow-loopback-pinentry &&
      test -f "$GNUPGHOME/gpg-agent.conf" &&
      ! grep -q allow-loopback-pinentry "$GNUPGHOME/gpg-agent.conf"; then
    echo allow-loopback-pinentry >> "$GNUPGHOME/gpg-agent.conf"
fi

gpg-connect-agent --agent-program="${GPG_AGENT}|--debug-quick-random" putval\ $token\ set /bye
if [ $? -ne 0 -o "$(gpg-connect-agent getval\ $token /bye 2>/dev/null | head -1)" \
      != "D set" ]; then
  echo "error starting gpg-agent" >&2
  exit 1
fi
exit 0