#!/bin/sh

# The MIT License (MIT)
#
# Copyright © 2026 pacman64
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the “Software”), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# bunits [options...] [quantity/unit pairs...]
#
# Better UNITS is an easier way to use the `units` command-line app, with a
# focus on shortcuts for converting into international units.
#
# Several unit shortcuts are available, including
#
#   ac, acre, acres
#   cup, cups
#   day, days
#   deg, degs, degree, degrees
#   f, fahr, fahren, fahrenheit, fahrenheits
#   floz,
#   ft, feet, foot, ft2, ft^2, sqft, sqfeet, ft3, ft^3, cuft, cufeet
#   gal, gallon, gallons
#   gb, gib, gibi, gibibytes
#   hr, hour, hours
#   in, inch, inches
#   kb, kib, kibi, kibibytes
#   lb, lbs, pound, pounds
#   mb, mib, mibi, mibibytes
#   mi, mile, miles, mi2, mi^2, miles^2, sqmi, sqmile, sqmiles
#   mi3, mi^3, miles^3, cumi, cumile, cumiles
#   min, minute, minutes
#   mph
#   nmi, nmile, nmiles, nmi2, nmi^2, nmile^2, nmiles^2
#   oz, ozs, ounce, ounces
#   pt, pts, pint, pints, uspint, uspints
#   tb, tib, tibi, tibibytes
#   yd, yds, yard, yards, yd2, yds2, yd^2, yds^2, yard^2, yards^2
#   wk, week, weeks
#
# The options are, available both in single and double-dash versions
#
#   -h, -help    show this help message


case "$1" in
    -h|--h|-help|--help)
        awk '/^# +bunits /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
        exit 0
    ;;
esac

[ "$1" = '--' ] && shift

if [ $# -lt 2 ]; then
    awk '/^# +bunits /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
    exit 0
fi

conv="units -v -H ''"

while [ $# -ge 2 ]; do
    # unit="$(echo "$2" | awk '{ print tolower($0) }')"
    unit="$(echo "$2" | tr '[A-Z]' '[a-z]')"

    case "${unit}" in
        ac|acre|acres) ${conv} "$1 acres" kilometers^2;;
        cup|cups) ${conv} "$1 cups" liters;;
        day|days) ${conv} "$1 days" seconds;;
        deg|degs|degree|degrees) ${conv} "$1 degrees" radians;;
        f|fahr|fahren|fahrenheit|fahrenheits) ${conv} "tempF($1)" tempC;;
        floz) ${conv} "$1 floz" milliliters;;
        ft|feet|foot) ${conv} "$1 feet" meters;;
        ft2|ft^2|sqft|sqfeet) ${conv} "$1 ft^2" meters^2;;
        ft3|ft^3|cuft|cufeet) ${conv} "$1 ft^3" meters^3;;
        gal|gallon|gals|gallons) ${conv} "$1 gallons" liters;;
        gb|gib|gibi|gibibytes) ${conv} "$1 gibibytes" bytes;;
        hr|hour|hours) ${conv} "$1 hours" seconds;;
        in|inch|inches) ${conv} "$1 inches" centimeters;;
        kb|kib|kibi|kibibytes) ${conv} "$1 kibibytes" bytes;;
        lb|lbs|pound|pounds) ${conv} "$1 pounds" kilograms;;
        mb|mib|mibi|mibibytes) ${conv} "$1 mibibytes" bytes;;
        mi|mile|miles) ${conv} "$1 miles" kilometers;;
        min|minute|minutes) ${conv} "$1 minutes" seconds;;
        mi2|mi^2|miles^2|sqmi|sqmile|sqmiles) ${conv} "$1 mi^2" kilometers^2;;
        mi3|mi^3|miles^3|cumi|cumile|cumiles) ${conv} "$1 mi^3" kilometers^3;;
        mph) ${conv} "$1 mph" kph;;
        nmi|nmile|nmiles) ${conv} "$1 nmi" kilometers;;
        nmi2|nmi^2|nmile^2|nmiles^2) ${conv} "$1 nmi^2" kilometers^2;;
        oz|ozs|ounce|ounces) ${conv} "$1 ounces" grams;;
        pt|pts|pint|pints|uspint|uspints) ${conv} "$1 uspints" liters;;
        tb|tib|tibi|tibibytes) ${conv} "$1 tibibytes" bytes;;
        yd|yds|yard|yards) ${conv} "$1 yards" meters;;
        yd2|yds2|yd^2|yds^2|yard^2|yards^2) ${conv} "$1 yards^2" meters^2;;
        wk|wks|week|weeks) ${conv} "$1 weeks" seconds;;
        *) printf "unsupported unit shortcut '%s'\n" "${unit}" >&2; exit 1;;
    esac

    shift
    shift
done

if [ $# -eq 1 ]; then
    printf "you forgot the unit for the last value\n" >&2
    exit 1
fi