#!/bin/bash

# Functions
# Error
function error {
    >&2 echo -e "\033[1;31mERROR:\033[0m $1"; shift
    exit "${1:-1}"
}

# Throw a value
function throw-value {
    error "Value \"${1}\" invalid for ${2}." 1
}

function screenshot-path {
    printf '%s%s-screenshot-%s.png' "${screenshot_d}/" "${LOGNAME}" "$(date +'%Y_%m_%d_%s')"
}

# Variables
declare -a prepend _command append
screenshot_d=/tmp

# Arguments
selection_mode="$1"; shift
saving_mode="$1"   ; shift

# Command building
_command+=(grim)
case "$selection_mode" in
    full)
        :
        ;;
    area)
        _command+=(-g -)
        prepend+=(slurp)
        ;;
    *)
        throw-value "$selection_mode" 'selection mode'
        ;;
esac
case "$saving_mode" in
    clip)
        _command+=(-)
        append+=(wl-copy -t image/png)
        ;;
    file)
        _command+=("$(screenshot-path)")
        ;;
    *)
        throw-value "$saving_mode" 'saving mode'
        ;;
esac

# Debug
#echo "${prepend[@]} | ${_command[@]} | ${append[@]}"
#exit 0

# Execution
set -xe
"${prepend[@]}" | "${_command[@]}" | "${append[@]}"