bash_completion.otp

################################################
# Bash completion function for otp.
################################################
#
# This file should be placed in the system's
# /etc/bash_completion.d/otp or it can be placed
# at ~/.bash_completion.otp and this line added
# to ~/.bash_completion:
#
# source ~/.bash_completion.otp
################################################
_otp()
{
    local cur

    COMPREPLY=()
    _get_comp_words_by_ref cur

    # On 10/28/2023, when gpg encryption was added, this
    # cache file was added. The primary reason was performance
    # because tab completion was sluggish with it requiring
    # gpg decryption each time. A little smarter here would be
    # to compare the timestamps between otp.conf and our cache,
    # but that would require knowing the location of otp.conf.
    cache_file=~/.otp_completions.cache
    MAX_AGE=$((60 * 30));  # Thirty minutes
    if [ -f "$cache_file" ]; then
      cache_mtime=$(date +%s -r "$cache_file")
      now=$(date +%s)
      let age=$(("$now" - "$cache_mtime"))
      if [ "$age" -gt 0 -a "$age" -lt "$MAX_AGE" ]; then
        COMPREPLY=( $( compgen -W "$( cat "$cache_file" )" -- "$cur" ) )
        return
      fi
    fi

    # If otp-test exists, we use it to see if completions are
    # possible. This was introduced on 10/28/2023, when gpg
    # encryption was added, because the user will need to provide
    # the passphrase when gpg-agent does not have it cached.
    # If otp-test returns a non-zero value then we print the message
    # that it provided. In most cases it will be that the passphrase
    # is needed for gpg to decrypt the config file.
    OTP_TEST=$(which otp-test)
    if [ -x "$OTP_TEST" ]; then
      msg=$(otp-test 2>/dev/null)
      if [ "$?" -eq 0 ]; then
        otp -l > "$cache_file"
        COMPREPLY=( $( compgen -W "$( cat "$cache_file" )" -- "$cur" ) )
      else
        echo "$msg"
      fi
    else
      otp -l > "$cache_file"
      COMPREPLY=( $( compgen -W "$( cat "$cache_file" )" -- "$cur" ) )
    fi
} &&
complete -F _otp otp