#compdef locate mlocate slocate

# Decide if we are using mlocate or slocate.
local ltype basename=${words[1]:t} input
# If we can't, use this guess.
local best_guess=mlocate

case $basename in
  ([ms]locate)
  ltype=$basename
  ;;

  (locate)
  input="$(_call_program locate $words[1] -V 2>&1)"
  case $input in
    (*mlocate*)
    ltype=mlocate
    ;;

    (*(#i)secure locate*)
    ltype=slocate
    ;;

    (*(#i)gnu locate*|*findutils*gnu*)
    ltype=gnu
    ;;

    (*illegal option*)
    if [[ $OSTYPE == (freebsd|openbsd|dragonfly|darwin)* ]]; then
      ltype=bsd
    else
      ltype=$best_guess
    fi
    ;;

    # guess
    (*)
    ltype=$best_guess
    ;;
  esac
  ;;

  (*)
  # too dangerous to run: guess
  ltype=$best_guess
esac

case $ltype in
  (mlocate)
  # actually, -d can take a colon-separate list
  # -r/--regexp mean no normal arguments, so shouldn't complete
  # -m and --mmap are ignored, so don't bother
  # -s and --stdio likewise
  _arguments -s -S : \
    {-b,--basename}'[match only the basename of files in the database]' \
    {-c,--count}'[output the number of matching entries]' \
    {-d,--database=}'[use alternative database]:database:_files' \
    {-e,--existing}'[restrict display to existing files]' \
    {-L,--follow}'[follow symbolic links to find existing files (default)]' \
    {-h,--help}'[show help]' \
    {-i,--ignore-case}'[ignore case distinctions in patterns]' \
    {-l,-n,--limit=}'[limit search results]:file limit: ' \
    {-P,-H,--nofollow}'[don'\''t follow symbolic links]' \
    {-0,--null}'[output separated by NUL characters]' \
    {-S,--statistics}'[show database statistics]' \
    {-q,--quiet}'[don'\''t report errors]' \
    {-r,--regexp=}'[search for given basic regexp]:basic regexp: ' \
    --regex'[patterns are extended regexps]' \
    {-V,--version}'[show version]' \
    {-w,--wholename}'[match entire file path (default)]' \
    '*:pattern: '
  ;;

  (slocate)
  # -d can take path
  # -e can take a comma-separated list of directories.
  # -f should complete list of file system types like mount
  _arguments -s -S : \
    -u'[create slocate database starting at path /]' \
    -U'[create slocate database starting at given path]:directory:_files -/' \
    -c'[parse GNU locate updatedb with -u, -U]' \
    -e'[exclude directories with -u, -U]:directories:_files -/' \
    -f'[exclude file system types from db with -u, -U]:file system:_file_systems' \
    -l'[security level]:level:(0 1)' \
    -q'[quiet mode]' \
    -n'[limit search results]:file limit: ' \
    -i'[case insensitive search]' \
    {-r,--regexp=}'[use basic regular expression]:regexp: ' \
    {-o,--output=}'[specify database to create]:database:_files' \
    {-d,--database=}'[specify database to search]:database:_files' \
    {-h,--help}'[display help]' \
    {-v,--verbose}'[display files when creating database]' \
    {-V,--version}'[display version]' \
    '*:pattern: '
  ;;

  (gnu)
  _arguments -s : \
    {-d,--database=}'[use alternative database]:database:_files' \
    {-e,--existing}'[restrict display to existing files]' \
    {-E,--non-existing}'[allow display of nonexistent files (default)]' \
    {-i,--ignore-case}'[ignore case distinctions in patterns]' \
    {-w,--wholename}'[match entire file path (default)]' \
    {-b,--basename}'[match only the basename of files in the database]' \
    {-l,-n,--limit=}'[limit search results]:file limit: ' \
    {-S,--statistics}'[show database statistics]' \
    {-0,--null}'[output separated by NUL characters]' \
    {-c,--count}'[output the number of matching entries]' \
    {-P,-H,--nofollow}'[don'\''t follow symbolic links]' \
    {-L,--follow}'[follow symbolic links to find existing files (default)]' \
    {-A,-all}'[match all arguments instead of at least one]' \
    {-p,--print}'[include search results with statistics or count]' \
    {-r,--regex=}'[patterns are regular expressions]:basic regexp: ' \
    --regextype='[select type of regular expression]' \
    {-V,--version}'[show version]' \
    --help'[show help]' \
    '*:pattern: '
  ;;

  (bsd)
  _arguments -s -S -A '-*' \
    '(-S)-0[separate file names by NUL characters]' \
    '(- *)-S[show database statistics and exit]' \
    '(-S)-c[output the number of matching file names]' \
    '(-S)*-d[specify database to search]:database:_files' \
    '(-S)-i[ignore case distinctions in pattern and database]' \
    '(-S)-l[limit output to specified number of file names]:file limit: ' \
    '(-S)-m[use mmap(2) instead of stdio(3) (default)]' \
    '(-S)-s[use stdio(3) instead of mmap(2)]' \
    '*:pattern: '
  ;;
esac