#compdef getent

local curcontext="$curcontext" state line expl ret=1
local services databases keys
local -a args
typeset -A opt_args

if _pick_variant -r is_gnu gnu='(Free Soft|GNU|GLIBC|Gentoo)' unix --version; then
  args+=(
    '(- 1 *)'{-\?,--help}'[display help information]'
    '(- 1 *)--usage[display a short usage message]'
    '(- 1 *)'{-V,--version}'[display version information]'
    '*'{-s+,--service=}'[specify service configuration to use]: :->services'
    '(-i --no-idn)'{-i,--no-idn}'[disable IDN encoding]'
  )
fi

_arguments -s -S -C "$args[@]" \
  '1:database:->databases' \
  '*:key:->keys' && ret=0

case $state in
  services)
    # @todo GNU getent supports both `-s svc` and `-s db:svc`; we only complete
    # the former here
    services=( {,/usr}/lib/{,*-linux-gnu/}libnss_*(N-.:fr:t:s/libnss_//) )
    _wanted services expl 'service or database:service' \
      compadd ${(u)services%-*} \
    && ret=0
  ;;
  databases)
    if [[ $is_gnu = gnu ]]; then
      databases=( "${(@)${(@f)$(_call_program databases $words[1] --help \
                   2>/dev/null)}[(r)Supported*,-1]}" )
      databases=( "${=${(@)databases[2,${(@)databases[(i)]}-1]}}" )
    elif [[ $OSTYPE = freebsd* ]]; then
      databases=( ${=${(f)"$(_call_program databases $words[1] 2>&1)"}[-1]} )
    else
      databases=( passwd group hosts ipnodes services protocols ethers networks netmasks )
    fi
    _wanted databases expl database compadd -a databases && ret=0
  ;;
  keys)
    keys=( ${(f)"$(_call_program keys $words[1] ${(kv)opt_args[(i)-s|--service]} $line[1] 2>/dev/null)"} )
    case $line[1] in
      *hosts) _wanted keys expl key compadd ${=keys#* } && ret=0 ;;
      networks|rpc|protocols|services)
        _wanted keys expl key compadd ${=keys%% *} && ret=0
      ;;
      aliases|passwd|shadow|group)
        _wanted keys expl key compadd ${keys%%:*} && ret=0
      ;;
      utmpx)
	if (( CURRENT > 3 )); then
	  _files && ret=0
	else
	  _wanted keys expl key compadd active lastlogin log && ret=0
	fi
      ;;
      *) _message -e keys key;;
    esac
  ;;
esac

return ret