#!/bin/env sh

TEMPLATE_FILE="$(dirname "$0")/verify-script.template"
if [ ! -f "$TEMPLATE_FILE" ]; then
    echo "'$TEMPLATE_FILE' not found. The template file should have come with this script." 1>&2
    exit 1
fi

FILE_PATH="$1"
if [ ! -f "$FILE_PATH" ]; then
    echo "'$FILE_PATH' not found" 1>&2
    exit 1
fi
FILE_NAME="$(basename "$FILE_PATH")"
FILE_HASH="$(sha256sum "$FILE_PATH" | awk '{print $1}')"

# TODO: argument for the message in case you want to apply it to many files.
read -r -p "Enter message to sign for the file: " MESSAGE
MESSAGE="$MESSAGE\n"

SUBSTITUTED_TEMPLATE=$(sed -e "s!{message}!$MESSAGE!g" -e "s!{filename}!$FILE_NAME!g" -e "s!{filehash}!$FILE_HASH!g" "$TEMPLATE_FILE")

printf '%s' "$SUBSTITUTED_TEMPLATE" > "$1.sh"