#compdef hostname

local variant=$OSTYPE ret=1
local -a context line state state_descr args aopts=( -A '-*' )
local -A opt_args

# May be overridden below
args=( '(-4 -6 -d -f -i -r -s)1: :_guard "^-*" "host name"' )

# On badly behaved systems it may be dangerous to call `hostname --help` or
# similar, so for now we'll avoid _pick_variant and just trust this. In the
# future, we should replace this by a method that can safely detect Solaris,
# BusyBox, etc. (@todo)
[[ $OSTYPE == linux* ]] &&
(( $+commands[nisdomainname] || $+commands[ypdomainname] )) &&
variant+=-net-tools

case $variant in
  *-net-tools)
    aopts=( )
    args=(
      '(: * -)'{-h,--help}'[display help information]'
      '(: * -)'{-V,--version}'[display version information]'
      + '(g)' # Get
      '(: gs s)'{-A,--all-fqdns}'[display FQDNs resolved from network interface addresses]'
      '(: gs s)'{-d,--domain}'[display DNS domain only]'
      '(: gs s)'{-f,--fqdn,--long}'[display host name with DNS domain (FQDN)]'
      '(: gs s)'{-i,--ip-address}'[display IP addresses for host (via DNS resolution)]'
      '(: gs s)'{-I,--all-ip-addresses}'[display IP addresses for host (via network interfaces)]'
      '(: gs s)'{-s,--short}'[display short host name only]'
      + '(gs)' # Get/set
      '(g)'{-y,--yp,--nis}'[display NIS domain only]'
      + s # Set
      '(-b --boot g)'{-b,--boot}'[always set a host name]'
      '(: -F --file g)'{-F+,--file=}'[read host name to set from specified file]: :_files'
      + o
      '(-F --file g)1: :->host-or-domain'
    )
  ;;
  darwin*|dragonfly*|freebsd*|netbsd*|openbsd*)
    args+=(
      '(: -4 -6 -d -f)-s[display short host name only]'
    )
    ;| # MATCH AGAIN
  darwin*|freebsd*)
    args+=(
      '(: -d -s)-f[display host name with DNS domain (FQDN)]'
      '(: -f -s)-d[display DNS domain only]'
    )
    ;;
  dragonfly*)
    args+=(
      '(: -6 -r)-4[use first IPv4 address on interface (with -i)]'
      '(: -4 -r)-6[use first IPv6 address on interface (with -i)]'
      '(: -r)-i+[retrieve host name via specified interface]: :_net_interfaces'
      '(: -4 -6 -i)-r+[retrieve host name via specified IP address]: :_bind_addresses'
    )
    ;;
esac

_arguments -s -S $aopts : $args && ret=0

[[ $state == host-or-domain ]] && {
  [[ -prefix -* ]] ||
  if [[ -n ${opt_args[(i)*-(-y|--yp|--nis)]} ]]; then
    _message -e nis-domains 'NIS domain' && ret=0
  else
    _message -e host-names 'host name' && ret=0
  fi
}

return ret
