#!/bin/bash

archive_dir="$(dirname "$0")/../archives"

input_file="${1}"
archive_pwd="${2}"
size="$3"

check_dependencies() {
	if ! mkdir -p "$archive_dir"; then
		echo "ERROR: Unable to create archive directory"
		exit 1
	fi

	if ! command -v 7z 2>&1 >/dev/null; then
		echo "ERROR: 7z must be installed"
		exit 1
	fi
}

check_input() {
	if [[ ! -e "${input_file}" ]]; then
		echo "ERROR: Input file '${input_file}' does not exist"
		exit 2
	fi

	echo "Archiving file/directory '${input_file}'" >&2
}

set_volumes() {
	volumes=

	if [[ "$size" =~ ^[1-9][0-9]*$ ]]; then
		volumes="-v${size}m"
	elif [[ -n "$size" ]]; then
		echo "Invalid size $size, must be a number"
		exit 2
	fi

	echo "Volumes set to '$volumes'" >&2
}

generate_name() {
	archive="$archive_dir/$(base64 /dev/urandom | tr -dc [:alnum:] | head -c 20).7z"

	echo "Generated archive name $archive" >&2
}

create_archive() {
	echo "Packing ${input_file} into archive $archive with password ${archive_pwd}"
	[[ -n "$volumes" ]] && echo "and volumes of size $size MB"

	7z a -mhe=on "-p${archive_pwd}" "$volumes" "$archive" "${input_file}" >&2
}

check_dependencies
check_input
set_volumes
generate_name
create_archive