#compdef ali anno burst comp dist flist flists folder folders forw inc mark mhlist mhmail mhn mhparam mhpath mhshow mhstore msgchk next packf pick prev refile repl rmf rmm scan show sortm whom

if [[ -z $commands[mhpath] ]]; then
  _message "MH commands are not available"
  return 1
fi

# Completion for all possible MH commands.
local mymhdir=${$(_call_program mhpath mhpath + 2>/dev/null):-~/Mail}
local mhlib=/usr/lib/mh

local prev="$words[CURRENT-1]" expl

if compset -P 1 -; then
  # get list of options, which MH commands can generate themselves
  # awk is just too icky to use for this, sorry.  send me one if
  # you come up with it.
  local -a options disp
  options=(
    $($words[1] -help | perl -ne 'if (/^\s*-\(?(\S+)/) {
       $n = $1;
       $n =~ s/\)//g;
       print $n =~ s/^\[([a-z]+)\]// ? "$n\n$1$n\n" : "$n\n";
    }')
  )
  if zstyle -t ":completion:${curcontext}:options" prefix-hidden; then
    _wanted options expl option compadd -d disp - "$options[@]"
  else
    disp=( -${options} )
    _wanted options expl option compadd -d disp - "$options[@]"
  fi    
  return
elif compset -P 1 '[+@]' || [[ "$prev" = -draftfolder ]]; then
  # Complete folder names.
  local mhpath

  if [[ $IPREFIX != '@' ]]; then
    [[ $IPREFIX = '+' ]] || IPREFIX=+
    mhpath=$mymhdir
  else
    mhpath=$(mhpath)
  fi

  _wanted files expl 'MH folder' _path_files -W mhpath -/
elif [[ "$prev" = -(editor|(whatnow|rmm|show|more)proc) ]]; then
  _command_names -e
elif [[ "$prev" = -file ]]; then
  _files
elif [[ "$prev" = -(form|audit|filter) ]]; then
  # Need some MH template file, which may be in our own MH directory
  # or with the standard library.
  local mhfpath
  # This is the only place we need mhlib, so leave the test till here.
  mhlib=${${$(mhparam mhlproc 2>/dev/null):h}:-/usr/lib/mh}
  mhfpath=($mymhdir $mhlib)

  _wanted files expl 'MH template file' _files -W mhfpath -g '*(-.)'
elif [[ $service = mhmail ]]; then
  _email_addresses
elif [[ "$prev" = -(no|)cc ]]; then
  _wanted -C "$prev" values expl 'CC address' compadd all to cc me
elif [[ "$prev" = -[rw]cache ]]; then
  _wanted -C "$prev" values expl cache compadd public private never ask
elif [[ "$prev" = -textfield ]]; then
  _wanted -C "$prev" -x headers expl header compadd -M 'm:{a-zA-Z}={A-Za-z}' \
      Subject From To cc
elif [[ "$prev" = -datefield ]]; then
  _wanted -C "$prev" -x headers expl header compadd -M 'm:{a-zA-Z}={A-Za-z}' \
      Delivery-Date
elif [[ $service = mhparam ]]; then
  _wanted parameters expl 'MH parameter' compadd - \
    ${${(f)"$(mhparam -all)"}%%:*}
elif [[ $service = ali ]]; then
  _email_addresses -n MH
elif compset -P '*:'; then
  _message -e number 'number of messages'
else
  # Generate sequences.
  local foldnam folddir f sequences mhneg ret=1

  compset -P '*-' # ignore start of message range

  for f in $words; do
    [[ $f = [@+]* ]] && foldnam=$f
  done
  if [[ $foldnam = '+'* ]]; then
    folddir=$mymhdir/${foldnam#+}
  elif [[ $foldnam = '@'* ]]; then
    folddir=$(mhpath)/${foldnam#@}
  else
    folddir=$(mhpath)
    # leaving foldnam empty works here
  fi

  sequences=( ${${(f)"$(mark $foldnam 2>/dev/null)"}%%:*} )
  mhneg="$(mhparam Sequence-Negation)" && sequences=( {,$mhneg}$^sequences )
  sequences+=( all first last prev next )
  _tags sequences
  while _tags; do
    while _next_label sequences expl sequence; do
      compadd -S ' ' -r '-: \t\n\-' "$expl[@]" -a sequences && ret=0
      _path_files -S ' ' -r '-: \t\n\-' "$expl[@]" -W folddir -g '<->(-.)' &&
          ret=0
    done
    (( ret )) || return 0
  done
  return ret
fi