# TODO(mmoss) Support configuring multiple repositories (e.g. stable and
# testing)
REPOCONFIG="@@REPOCONFIG@@"

APT_GET="`which apt-get 2> /dev/null`"
APT_CONFIG="`which apt-config 2> /dev/null`"

# Parse apt configuration and return requested variable value.
apt_config_val() {
  APTVAR="$1"
  if [ -x "$APT_CONFIG" ]; then
    "$APT_CONFIG" dump | sed -e "/^$APTVAR /"'!d' -e "s/^$APTVAR \"\(.*\)\".*/\1/"
  fi
}

# Install the repository signing key (see also:
# http://www.google.com/linuxrepositories/aboutkey.html)
install_key() {
  APT_KEY="`which apt-key 2> /dev/null`"
  if [ -x "$APT_KEY" ]; then
    "$APT_KEY" add - >/dev/null 2>&1 <<KEYDATA
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.4.2.2 (GNU/Linux)

mQGiBEXwb0YRBADQva2NLpYXxgjNkbuP0LnPoEXruGmvi3XMIxjEUFuGNCP4Rj/a
kv2E5VixBP1vcQFDRJ+p1puh8NU0XERlhpyZrVMzzS/RdWdyXf7E5S8oqNXsoD1z
fvmI+i9b2EhHAA19Kgw7ifV8vMa4tkwslEmcTiwiw8lyUl28Wh4Et8SxzwCggDcA
feGqtn3PP5YAdD0km4S4XeMEAJjlrqPoPv2Gf//tfznY2UyS9PUqFCPLHgFLe80u
QhI2U5jt6jUKN4fHauvR6z3seSAsh1YyzyZCKxJFEKXCCqnrFSoh4WSJsbFNc4PN
b0V0SqiTCkWADZyLT5wll8sWuQ5ylTf3z1ENoHf+G3um3/wk/+xmEHvj9HCTBEXP
78X0A/0Tqlhc2RBnEf+AqxWvM8sk8LzJI/XGjwBvKfXe+l3rnSR2kEAvGzj5Sg0X
4XmfTg4Jl8BNjWyvm2Wmjfet41LPmYJKsux3g0b8yzQxeOA4pQKKAU3Z4+rgzGmf
HdwCG5MNT2A5XxD/eDd+L4fRx0HbFkIQoAi1J3YWQSiTk15fw7RMR29vZ2xlLCBJ
bmMuIExpbnV4IFBhY2thZ2UgU2lnbmluZyBLZXkgPGxpbnV4LXBhY2thZ2VzLWtl
eW1hc3RlckBnb29nbGUuY29tPohjBBMRAgAjAhsDBgsJCAcDAgQVAggDBBYCAwEC
HgECF4AFAkYVdn8CGQEACgkQoECDD3+sWZHKSgCfdq3HtNYJLv+XZleb6HN4zOcF
AJEAniSFbuv8V5FSHxeRimHx25671az+uQINBEXwb0sQCACuA8HT2nr+FM5y/kzI
A51ZcC46KFtIDgjQJ31Q3OrkYP8LbxOpKMRIzvOZrsjOlFmDVqitiVc7qj3lYp6U
rgNVaFv6Qu4bo2/ctjNHDDBdv6nufmusJUWq/9TwieepM/cwnXd+HMxu1XBKRVk9
XyAZ9SvfcW4EtxVgysI+XlptKFa5JCqFM3qJllVohMmr7lMwO8+sxTWTXqxsptJo
pZeKz+UBEEqPyw7CUIVYGC9ENEtIMFvAvPqnhj1GS96REMpry+5s9WKuLEaclWpd
K3krttbDlY1NaeQUCRvBYZ8iAG9YSLHUHMTuI2oea07Rh4dtIAqPwAX8xn36JAYG
2vgLAAMFB/wKqaycjWAZwIe98Yt0qHsdkpmIbarD9fGiA6kfkK/UxjL/k7tmS4Vm
CljrrDZkPSQ/19mpdRcGXtb0NI9+nyM5trweTvtPw+HPkDiJlTaiCcx+izg79Fj9
KcofuNb3lPdXZb9tzf5oDnmm/B+4vkeTuEZJ//IFty8cmvCpzvY+DAz1Vo9rA+Zn
cpWY1n6z6oSS9AsyT/IFlWWBZZ17SpMHu+h4Bxy62+AbPHKGSujEGQhWq8ZRoJAT
G0KSObnmZ7FwFWu1e9XFoUCt0bSjiJWTIyaObMrWu/LvJ3e9I87HseSJStfw6fki
5og9qFEkMrIrBCp3QGuQWBq/rTdMuwNFiEkEGBECAAkFAkXwb0sCGwwACgkQoECD
D3+sWZF/WACfeNAu1/1hwZtUo1bR+MWiCjpvHtwAnA1R3IHqFLQ2X3xJ40XPuAyY
/FJG
=Quqp
-----END PGP PUBLIC KEY BLOCK-----
KEYDATA
  fi
}

# Set variables for the locations of the apt sources lists.
find_apt_sources() {
  APTDIR=$(apt_config_val Dir)
  APTETC=$(apt_config_val 'Dir::Etc')
  APT_SOURCES="$APTDIR$APTETC$(apt_config_val 'Dir::Etc::sourcelist')"
  APT_SOURCESDIR="$APTDIR$APTETC$(apt_config_val 'Dir::Etc::sourceparts')"
}

# Add the Google repository to the apt sources.
# Returns:
# 0 - no update necessary
# 1 - sources were updated
# 2 - error
update_sources_lists() {
  find_apt_sources

  if [ -d "$APT_SOURCESDIR" ]; then
    # Nothing to do if it's already there.
    SOURCELIST=$(grep -H "$REPOCONFIG" "$APT_SOURCESDIR/@@PACKAGE@@.list" \
      2>/dev/null | cut -d ':' -f 1)
    if [ -n "$SOURCELIST" ]; then
      return 0
    fi

    printf "$REPOCONFIG\n" > "$APT_SOURCESDIR/@@PACKAGE@@.list"
    if [ $? -eq 0 ]; then
      return 1
    fi
  fi
  # TODO(mmoss) What are the chances that any distro we support doesn't provide
  # APT_SOURCESDIR nowadays? Should we just bail if we get here? It makes
  # cleanup easier if we don't have to worry about undoing changes to
  # APT_SOURCES, which may conflict with other changes or manual edits.

  # Nothing to do if it's already there.
  SOURCELIST=$(grep -H "$REPOCONFIG" "$APT_SOURCES" 2>/dev/null \
    | cut -d ':' -f 1)
  if [ -n "$SOURCELIST" ]; then
    return 0
  fi

  if [ -w "$APT_SOURCES" ]; then
    printf "$REPOCONFIG #@@PACKAGE@@\n" >> "$APT_SOURCES"
    return 1
  fi

  return 2
}

# Remove a repository from the apt sources.
# Returns:
# 0 - successfully removed, or not configured
# 1 - failed to remove
clean_sources_lists() {
  find_apt_sources

  if [ -d "$APT_SOURCESDIR" ]; then
    # Check if our package.list has this repo configured.
    SOURCELIST=$(grep -H "$REPOCONFIG" "$APT_SOURCESDIR/@@PACKAGE@@.list" \
      2>/dev/null | cut -d ':' -f 1)
    if [ -n "$SOURCELIST" ]; then
      sed -i -e "\,$REPOCONFIG,d" "$SOURCELIST"
      if [ $? -ne 0 ]; then
        return 1
      fi
      # Delete file if empty (all comments or whitespace)
      LINECOUNT=$(sed -e '/^[[:space:]]*\(#.*\|$\)/d' "$SOURCELIST" | wc -l)
      if [ "$LINECOUNT" = "0" ]; then
        rm -f "$SOURCELIST"
      fi
    fi
  fi

  # Also check if it was added to the global sources.list
  SOURCELIST=$(grep -H "$REPOCONFIG" "$APT_SOURCES" 2>/dev/null \
    | cut -d ':' -f 1)
  if [ -n "$SOURCELIST" ]; then
    # Remove repo line(s) marked with our package comment
    sed -i -e "\,$REPOCONFIG #@@PACKAGE@@,d" "$SOURCELIST"
    if [ $? -ne 0 ]; then
      return 1
    fi
  fi

  return 0
}