_autocomplete.history_lines

#autoload

_autocomplete.history_lines() {
  local tag=history-lines
  _tags $tag
  _tags ||
      return 1
  _requested $tag ||
      return 1

  local -A events=()
  local -i min_lines max_lines
  zstyle -s ":autocomplete:${curcontext}:" list-lines min_lines ||
      min_lines=16
  (( max_lines = min( min_lines, HISTNO - 1, LINES - BUFFERLINES ) ))

  if [[ -z $BUFFER ]]; then
    if [[ $curcontext == *-forward:* ]]; then
      local -i inc=1 histno=1
    else
      local -i inc=-1 histno=$(( HISTNO - 1 ))
    fi
    if [[ -o histfindnodups ]]; then
      while (( $#events[@] < max_lines && 0 < histno && histno < HISTNO )); do
        [[ -v history[$histno] && ! -v events[$history[$histno]] ]] &&
            events[$history[$histno]]=$histno
        (( histno += inc ))
      done
      events=( "${(@Oa)${(@kv)events}}" )
    else
      while (( $#events[@] < max_lines && 0 < histno && histno < HISTNO )); do
        [[ -v history[$histno] ]] &&
            events[$histno]="$history[$histno]"
        (( histno += inc ))
      done
    fi
  else
    local -aU queries results reply
    if [[ $curcontext == *-incremental-*:* ]]; then
      local word=$IPREFIX$PREFIX$SUFFIX$ISUFFIX
      local lbuffer="${words[1,CURRENT-1]}[[:blank:]]#"
      local rbuffer="[[:blank:]]#${words[CURRENT+1,-1]}"
      queries=( "$lbuffer*((#ia"{0..$(( min(7, $#word / 3) ))}")${(b)word})*$rbuffer" )
    else
      queries=( '(#ia'{0..$(( min(7, $#words / 3) ))}')*'${words[CURRENT]//$'\0'/*}'*' )
    fi
    if [[ -o histfindnodups ]]; then
      local -a numbers
      local q; for q in $queries[@]; do
        numbers=( "${(@k)history[(R)$~q]}" )
        (( $#numbers[@] > 0 )) &&
            break
      done
      local -a lines=( "${(@v)history[(I)(${(~j:|:)numbers})]}" )
      if [[ $curcontext != *-forward:* ]]; then
        numbers=( "${(@Oa)numbers}" )
        lines=( "${(@Oa)lines}" )
      fi
      events=( "${(@)lines:^numbers}" )
      events=( "${(@Oa)${(@kv)events}}" )
    else
      local q; for q in $queries[@]; do
        events=( "${(@kv)history[(R)$~q]}" )
        (( $#events[@] > 0 )) &&
            break
      done
    fi
  fi

  (( $#events[@] )) ||
      return

  local -a displays=()
  printf -v displays "%s:%s" "${(@kv)events}"
  displays=( "$displays[@]" )

  local -i diff=$(( $#displays[@] - max_lines ))
  local -a sopt
  if [[ $curcontext == *-incremental-* ]]; then
    if [[ $curcontext == *-forward:* ]]; then
        displays=( ${(@n)displays} )
    else
        displays=( ${(@On)displays} )
    fi
    (( diff > 0 )) &&
        shift -p "$diff" displays
    if [[ -n $BUFFER ]]; then
      _autocomplete.sort_by_length $displays[@]
      displays=( $reply[@] )
    fi
    sopt=( -S '' )
  else
    displays=( ${(@n)displays} )
    (( diff > 0 )) &&
        shift "$diff" displays
    sopt=( -S ';' -r '^ ' )
  fi

  local -a matches=( "${displays[@]##[[:blank:]]#<->:}" )
  [[ $curcontext == *-incremental-* ]] &&
      matches=( "${(@)${(@)matches[@]##$~lbuffer}%%$~rbuffer}" )

  local -a match mbegin mend
  displays=(
      "${(@r:COLUMNS-1:)displays[@]/%(#b)(<->):(*)/${(l:$#HISTNO:)match[1]} ${(V)${(Z+C+)match[2]}}}"
      )

  local _comp_no_ignore=1 expl
  _description -2V "$tag" expl 'history line'
  compadd "$expl[@]" "$sopt[@]" -QU -ld displays -a matches
}

_autocomplete.history_lines "$@"