#autoload

# Complete the arguments of the current command according to the
# descriptions given as arguments to this function.

local long args rest ws cur nth def nm expl descr action opt arg tmp

# Associative arrays used to collect information about the options.

typeset -A opts mopts dopts dmopts odopts odmopts

# See if we support long options, too.

nth=$argv[(I)--]
if (( nth )); then
  long=( "${(@)argv[nth+1,-1]}" )
  argv=("${(@)argv[1,nth-1]}")
else
  long=()
fi

# Now parse the arguments...

args=()
nth=1
while (( $# )); do

  # This describes a one-shot option.

  if [[ "$1" = [-+]* ]]; then
    if [[ "$1" = *:* ]]; then

      # If the option name ends in a `-', the first argument comes
      # directly after the option, if it ends in a `+', the first
      # argument *may* come directly after the option, otherwise it
      # is in the next word.

      if [[ "$1" = [^:]##-:* ]]; then
        dopts[${${1%%:*}[1,-2]}]="${1#*:}"
      elif [[ "$1" = [^:]##+:* ]]; then
        odopts[${${1%%:*}[1,-2]}]="${1#*:}"
      else
        opts[${1%%:*}]="${1#*:}"
      fi
    else
      opts[$1]=''
    fi
  elif [[ "$1" = \*[-+]* ]]; then

    # The same for options that may appear more than once.

    if [[ "$1" = *:* ]]; then
      if [[ "$1" = [^:]##-:* ]]; then
        dmopts[${${1[2,-1]%%:*}[1,-2]}]="${1#*:}"
      elif [[ "$1" = [^:]##+:* ]]; then
        odmopts[${${1[2,-1]%%:*}[1,-2]}]="${1#*:}"
      else
        mopts[${1[2,-1]%%:*}]="${1#*:}"
      fi
    else
      mopts[${1[2,-1]}]=''
    fi
  elif [[ "$1" = \*:* ]]; then

    # This is `*:...', describing `all other arguments'.

    rest="${1[3,-1]}"
  elif [[ "$1" = :* ]]; then

    # This is `:...', describing `the next argument'.

    args[nth++]="${1#*:}"
  else

    # And this is `n:...', describing the `n'th argument.

    args[${1%%:*}]="${1#*:}"
    nth=$(( ${1%%:*} + 1 ))
  fi
  shift
done

if [[ $#long -ne 0 && "$PREFIX" = --* ]]; then

   # If the current words starts with `--' and we should use long
   # options, just call...

  _long_options "$long[@]"
else

  # Otherwise parse the command line...

  ws=( "${(@)words[2,-1]}" )
  cur=$(( CURRENT-2 ))
  nth=1

  # ...until the current word is reached.

  while [[ cur -gt 0 ]]; do

    # `def' holds the description for the option we are currently after.
    # Check if the next argument for the option is optional.

    if [[ "$def" = :* ]]; then
      opt=yes
    else
      opt=''
    fi
    arg=''

    # Remove one description/action pair from `def' if that isn't empty.

    if [[ -n "$def" ]]; then
      if [[ "$def" = ?*:*:* ]]; then
        def="${def#?*:*:}"
      else
        def=''
      fi
    else

      # If it is empty, and the word starts with `--' and we should
      # complete long options, just ignore this word, otherwise make sure
      # we test for options below and handle normal arguments.

      if [[ $#long -eq 0 || "$ws[1]" != --* ]]; then
        opt=yes
	arg=yes
      else
        def=''
      fi
    fi

    if [[ -n "$opt" ]]; then

      # `opt' was set above if we have to test if the word is an option.
      # We first test for the simple options -- those without arguments or
      # those whose arguments have to be given as separate words.

      if (( $+opts[$ws[1]] )); then

        # Options that may only be given once are removed from the
        # associative array so that we are not offered them again.

        def="$opts[$ws[1]]"
        unset "opts[$ws[1]]"
      elif (( $+mopts[$ws[1]] )); then
        def="$mopts[$ws[1]]"
      else

        # If the word is none of the simple options, test for those
        # whose first argument has to or may come directly after the
        # option. This is done in four loops looking very much alike.

        if (( $#dopts )); then

	  # First we get the option names.

	  tmp=( "${(@k)dopts}" )

	  # Then we loop over them and see if the current word begins
	  # with one of the option names.

	  while (( $#tmp )); do
	    [[ "$ws[1]" = ${tmp[1]}* ]] && break
	    shift 1 tmp
	  done

	  if (( $#tmp )); then

	    # It does. So use the description for it, but only from
	    # the second argument on, because we are searching the
	    # description for the next command line argument.

	    opt=''
	    def="$dopts[$tmp[1]]"
	    unset "dopts[$tmp[1]]"
	    if [[ "$def" = ?*:*:* ]]; then
              def="${def#?*:*:}"
            else
              def=''
	    fi
          fi
        fi
	if [[ -n "$opt" && $#dmopts -ne 0 ]]; then
	  tmp=( "${(@k)dmopts}" )
	  while (( $#tmp )); do
	    [[ "$ws[1]" = ${tmp[1]}* ]] && break
	    shift 1 tmp
	  done

	  if (( $#tmp )); then
	    opt=''
	    def="$dmopts[$tmp[1]]"
	    if [[ "$def" = ?*:*:* ]]; then
              def="${def#?*:*:}"
            else
              def=''
            fi
          fi
	fi
        if [[ -n "$opt" && $#odopts -ne 0 ]]; then
	  tmp=( "${(@k)odopts}" )
	  while (( $#tmp )); do
	    [[ "$ws[1]" = ${tmp[1]}* ]] && break
	    shift 1 tmp
	  done

	  if (( $#tmp )); then
	    opt=''
	    def="$odopts[$tmp[1]]"
	    unset "odopts[$tmp[1]]"

	    # For options whose first argument *may* come after the
	    # option, we skip over the first description only if there
	    # is something after the option name on the line.

	    if [[ "$ws[1]" != "$tmp[1]" ]]; then
	      if [[ "$def" = ?*:*:* ]]; then
                def="${def#?*:*:}"
              else
                def=''
              fi
	    fi
          fi
        fi
	if [[ -n "$opt" && $#odmopts -ne 0 ]]; then
	  tmp=( "${(@k)odmopts}" )
	  while (( $#tmp )); do
	    [[ "$ws[1]" = ${tmp[1]}* ]] && break
	    shift 1 tmp
	  done

	  if (( $#tmp )); then
	    opt=''
	    def="$odmopts[$tmp[1]]"
	    if [[ "$ws[1]" != "$tmp[1]" ]]; then
	      if [[ "$def" = ?*:*:* ]]; then
                def="${def#?*:*:}"
              else
                def=''
              fi
            fi
          fi
	fi

	# If we didn't find a matching option description and we were
	# told to use normal argument descriptions, just increase
	# our counter `nth'.

        if [[ -n "$opt" && -n "$arg" ]]; then
          def=''
	  (( nth++ ))
        fi
      fi
    fi

    shift 1 ws
    (( cur-- ))
  done

  # Now generate the matches.

  nm="$compstate[nmatches]"

  if [[ -z "$def" || "$def" = :* ]]; then

    # We either don't have a description for an argument of an option
    # or we have a description for a optional argument.

    if [[ -z "$def" ]]; then

      # If we have none at all, use the one for this argument position.

      def="$args[nth]"
      [[ -z "$def" ]] && def="$rest"
    fi

    # In any case, we have to complete option names here, but we may
    # be in a string that starts with an option names and continues with
    # the first argument, test that (again, four loops).

    opt=yes
    if (( $#dopts )); then

      # Get the option names.

      tmp=( "${(@k)dopts}" )
      while (( $#tmp )); do
        if compset -P "$tmp[1]"; then

	  # The current string starts with the option name, so ignore
	  # that and complete the rest of the string.

	  def="$dopts[$tmp[1]]"
	  opt=''
	  break
        fi
	shift 1 tmp
      done
    fi
    if [[ -n "$opt" && $#dmopts -ne 0 ]]; then
      tmp=( "${(@k)dmopts}" )
      while (( $#tmp )); do
        if compset -P "$tmp[1]"; then
	  def="$dmopts[$tmp[1]]"
	  opt=''
	  break
        fi
	shift 1 tmp
      done
    fi
    if [[ -n "$opt" && $#odopts -ne 0 ]]; then
      tmp=( "${(@k)odopts}" )
      while (( $#tmp )); do
        if compset -P "$tmp[1]"; then
	  def="$odopts[$tmp[1]]"
	  opt=''
	  break
        fi
	shift 1 tmp
      done
    fi
    if [[ -n "$opt" && $#odmopts -ne 0 ]]; then
      tmp=( "${(@k)odmopts}" )
      while (( $#tmp )); do
        if compset -P "$tmp[1]"; then
	  def="$odmopts[$tmp[1]]"
	  opt=''
	  break
        fi
	shift 1 tmp
      done
    fi
    if [[ -n "$opt" ]]; then

      # We aren't in an argument directly after a option name, so
      # all option names are possible matches.

      _description expl option
      compadd "$expl[@]" - "${(@k)opts}" "${(@k)mopts}" \
                           "${(@k)dopts}" "${(@k)dmopts}" \
			   "${(@k)odopts}" "${(@k)odmopts}"
    fi
  fi

  # Now add the matches from the description, if any.

  if [[ -n "$def" ]]; then

    # Ignore the leading colon describing optional arguments.

    [[ "$def" = :* ]] && def="$def[2,-1]"

    # Get the description and the action.

    descr="${def%%:*}"
    action="${${def#*:}%%:*}"

    _description expl "$descr"

    if [[ -z "$action" ]]; then

      # An empty action means that we should just display a message.
      _message "$descr"
      return 1
    elif [[ "$action[1]" = \( ]]; then

      # Anything inside `(...)' is added directly.

      compadd "$expl[@]" - ${=action[2,-2]}
    elif [[ "$action" = \ * ]]; then

      # If the action starts with a space, we just call it.

      $=action
    else

      # Otherwise we call it with the description-arguments built above.

      action=( $=action )
      "$action[1]" "$expl[@]" "${(@)action[2,-1]}"
    fi
  fi

  # Set the return value.

  [[  nm -ne "$compstate[nmatches]" ]]
fi