# -*- mode: snippet -*-
# name: Bash script template with standard CLI processing and helper functions.
# key: bash-script
# contributor: Branko Majic <branko@majic.rs>
# type: snippet
# --
#!/bin/bash
#
# `(file-name-nondirectory (buffer-file-name))`
#
# Copyright (C) `(format-time-string "%Y")`, Branko Majic <branko@majic.rs>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

# Treat unset variables as errors.
set -u

PROGRAM="`(file-name-nondirectory (buffer-file-name))`"
VERSION="${1:version}"

function usage() {
    cat <<EOF
\$PROGRAM \$VERSION, ${2:short description }

Usage:
  \$PROGRAM [OPTIONS] ${3:arguments}
EOF
}

function short_help() {
    cat <<EOF
\$(usage)

For more details see \$PROGRAM -h.
EOF
}

function long_help() {
    cat <<EOF
\$(usage)

\$PROGRAM ${4:long description}

\$PROGRAM accepts the following options:

    -q
        Quiet mode.
    -d
        Enable debug mode.
    -v
        Show script version and licensing information.
    -h
        Show full help.

Please report bugs and send feature requests to <branko@majic.rs>.
EOF
}

function version() {
        cat <<EOF
\$PROGRAM, version \$VERSION

+-----------------------------------------------------------------------+
| Copyright (C) `(format-time-string "%Y")`, Branko Majic <branko@majic.rs>                    |
|                                                                       |
| This program is free software: you can redistribute it and/or modify  |
| it under the terms of the GNU General Public License as published by  |
| the Free Software Foundation, either version 3 of the License, or     |
| (at your option) any later version.                                   |
|                                                                       |
| This program is distributed in the hope that it will be useful,       |
| but WITHOUT ANY WARRANTY; without even the implied warranty of        |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         |
| GNU General Public License for more details.                          |
|                                                                       |
| You should have received a copy of the GNU General Public License     |
| along with this program.  If not, see <http://www.gnu.org/licenses/>. |
+-----------------------------------------------------------------------+

EOF
}

# Set-up colours for message printing if we're not piping and terminal is
# capable of outputting the colors.
_COLOR_TERMINAL=\$(tput colors 2>&1)
if [[ -t 1 ]] && (( _COLOR_TERMINAL > 0 )); then
    _TEXT_BOLD=\$(tput bold)
    _TEXT_WHITE=\$(tput setaf 7)
    _TEXT_BLUE=\$(tput setaf 6)
    _TEXT_GREEN=\$(tput setaf 2)
    _TEXT_YELLOW=\$(tput setaf 3)
    _TEXT_RED=\$(tput setaf 1)
    _TEXT_RESET=\$(tput sgr0)
else
    _TEXT_BOLD=""
    _TEXT_WHITE=""
    _TEXT_BLUE=""
    _TEXT_GREEN=""
    _TEXT_YELLOW=""
    _TEXT_RED=""
    _TEXT_RESET=""
fi

# Set-up functions for printing coloured messages.
function debug() {
    if [[ $DEBUG != 0 ]]; then
        echo "\${_TEXT_BOLD}\${_TEXT_BLUE}[DEBUG]\${_TEXT_RESET}" "\$@"
    fi
}

function info() {
    if [[ $QUIET == 0 ]]; then
        echo "\${_TEXT_BOLD}\${_TEXT_WHITE}[INFO] \${_TEXT_RESET}" "\$@"
    fi
}

function success() {
    if [[ $QUIET == 0 ]]; then
        echo "\${_TEXT_BOLD}\${_TEXT_GREEN}[OK]   \${_TEXT_RESET}" "\$@"
    fi
}

function warning() {
    echo "\${_TEXT_BOLD}\${_TEXT_YELLOW}[WARN] \${_TEXT_RESET}" "\$@" >&2
}

function error() {
    echo "\${_TEXT_BOLD}\${_TEXT_RED}[ERROR]\${_TEXT_RESET}" "\$@" >&2
}

# Define error codes.
SUCCESS=0
ERROR_ARGUMENTS=1

# Disable debug and quiet modes by default.
DEBUG=0
QUIET=0

# If no arguments were given, just show usage help.
if [[ -z \${1-} ]]; then
    short_help
    exit "$SUCCESS"
fi

# Parse the arguments
while getopts "qdvh" opt; do
    case "\$opt" in
        q) QUIET=1;;
        d) DEBUG=1;;
        v) version
           exit "$SUCCESS";;
        h) long_help
           exit "$SUCCESS";;
        *) short_help
           exit "$ERROR_ARGUMENTS";;
    esac
done
i=\$OPTIND
shift \$(( i-1 ))

# Quiet and debug are mutually exclusive.
if [[ \$QUIET != 0 && \$DEBUG != 0 ]]; then
    error "Quiet and debug options are mutually exclusive."
    exit "\$ERROR_ARGUMENTS"
fi