#!/usr/bin/env bash

# A small script to standardize handling boolean environment variables.
# Exits with 0 if and only if the given name corresponds to an env var that is defined, and has value of "true", 1, or "yes".
# A variable not defined defaults to false, so if you want to set a certain variable to default to true (like we do
# for IS_DEVNET for example), export it from `.envrc.vars`
# example usage:
# if (env-bool IS_DEVNET); then echo "you are in devnet mode"; fi
# if ! (env-bool IS_DEVNET); then echo "you are NOT in devnet mode"; fi

var=$1
val=${!var}

if [ -z "$val" ]; then
  # the variable is not defined, defaulting to false
  exit 1
fi

if [ "$val" == "true" ] || [ "$val" == "1" ] || [ "$val" == "yes" ]; then exit 0; fi
if [ "$val" == "false" ] || [ "$val" == "0" ] || [ "$val" == "no" ]; then exit 1; fi

echo "Warning: Unexpected value for variable $var: $val (defaulting to false)" >&2

exit 1