#!/bin/bash
#
# list_pkg_ids_by_regexp
#

###
### settings
###

set -e               # exit on any uncaught error
set +o histexpand    # don't expand history expressions
shopt -s nocasematch # case-insensitive regular expressions

###
### functions
###

warn () {
    local message="$@"
    message="${message//\\t/$'\011'}"
    message="${message//\\n/$'\012'}"
    message="${message%"${message##*[![:space:]]}"}"
    printf "%s\n" "$message" 1>&2
}

die () {
    warn "$@"
    exit 1
}

fail_informatively () {
    local message="No match."
    if ! [[ "$1" =~ '*' ]]; then
        message="$message  Suggestion: try '${1}.*'"
    fi
    die "$message"
}

analyze_regexp () {
    if [[ "$1" =~ ^\^ ]]; then
        warn "Note: pkgutil regular expressions are implicitly anchored with '^' at start"
    fi
    if [[ "$1" =~ \$$ ]]; then
        warn "Note: pkgutil regular expressions are implicitly anchored with '$' at end"
    fi
}

###
### main
###

_list_pkg_ids_by_regexp () {
    analyze_regexp "$1"
    if ! /usr/sbin/pkgutil --pkgs="$1"; then
        fail_informatively "$1"
    fi
}

# process args
if [[ $1 =~ ^-+h(elp)?$ || $# -ne 1 ]]; then
    printf "list_pkg_ids_by_regexp <regexp>

Print pkg receipt IDs for installed packages matching a regular
expression, which may be useful in a Cask uninstall stanza, eg

    uninstall pkgutil: 'pkg.regexp.goes.here'

Unlike most other scripts in this directory, package IDs attributed to
Apple are NOT excluded from the output.  This is to avoid uninstalling
essential system files due to an exuberant regexp.

For more information, see

    https://github.com/caskroom/homebrew-cask/blob/master/doc/cask_language_reference/stanzas/uninstall.md

"
    exit
fi

# dispatch main
_list_pkg_ids_by_regexp "${@}"

#