#!/bin/bash

__inarray() {
  local i
  for i in "${@:2}"; do
    [[ $i == "$1" ]] && return
  done
}

__hasprefix() {
  local i
  for i in "${@:2}"; do
    [[ $i = "$1"* ]] && return
  done
}

_pkgfile() {
  local cur=${COMP_WORDS[COMP_CWORD]} prev=${COMP_WORDS[COMP_CWORD - 1]} prevprev=${COMP_WORDS[COMP_CWORD - 2]}

  local shortopts=(-l -s -u -b -C -D -g -i -q -R -r -h -V -v -w -z -0)
  local longopts=(--list --search --update --binaries --glob --ignorecase
                  --quiet --regex --help --version --verbose --raw --null)
  local longoptsarg=(--compress --config --cachedir --repo)
  local allopts=("${shortopts[@]}" "${longopts[@]}" "${longoptsarg[@]}")

  local compressopts=(none gzip bzip2 lz4 lzma lzop xz)

  # maybe mangle the arguments in case we're looking at a --longopt=$val
  [[ $cur = '=' ]] && cur=
  if [[ $prev = '=' ]] && __inarray "$prevprev" "${allopts[@]}"; then
    prev=$prevprev
  fi

  case $prev in
    -C|--config)
      COMPREPLY=($(compgen -f -- "$cur"))
      compopt -o filenames
      return 0
      ;;
    -D|--cachedir)
      COMPREPLY=($(compgen -d -- "$cur"))
      compopt -o filenames
      return 0
      ;;
    -z|--compress)
      COMPREPLY=($(compgen -W '${compressopts[*]}' -- "$cur"))
      return 0
      ;;
    -R|--repo)
      local repos=$(sed '/^\[\(.*\)\]$/!d;s//\1/g;/options/d' /etc/pacman.conf)
      COMPREPLY=($(compgen -W '$repos' -- "$cur"))
      return 0
      ;;
  esac

  case $cur in
    --*)
      if __hasprefix "$cur" "${longoptsarg[@]}"; then
        compopt -o nospace
        COMPREPLY=($(compgen -W '${longoptsarg[*]}' -S = -- "$cur"))
      else
        COMPREPLY=($(compgen -W '${longopts[*]}' -- "$cur"))
      fi
      return 0
      ;;
    -*)
      COMPREPLY=($(compgen -W '${allopts[*]}' -- "$cur"))
      return 0
      ;;
    *)
      # completion based on mode -- always take the last specified
      local i j w mode
      for (( i = 1; i < ${#COMP_WORDS[*]}; ++i )); do
        w=${COMP_WORDS[i]}
        if (( i == 1 )) || [[ ${COMP_WORDS[i-1]} != -* ]]; then
          case $w in
            # mode from shortopt (possibly a bunch mushed together)
            -[^-]*)
              for (( j = 0; j < ${#w}; j++ )); do
                case ${w:j:1} in
                  l|s)
                    mode=${w:j:1}
                    ;;
                esac
              done
              ;;
            # mode from long opt
            --list|--search)
              mode=${w#--}
              ;;
          esac
        fi
      done
      case $mode in
        l|list)
          # complete based on package matches
          COMPREPLY=($(compgen -W '$(command pacman -Ssq)' -- "$cur"))
          return 0
          ;;
        *)
          COMPREPLY=($(compgen -W '${allopts[*]}' -- "$cur"))
          return 0
          ;;
      esac
  esac
}

complete -F _pkgfile pkgfile

# ex:et ts=2 sw=2 ft=sh