#!/usr/bin/env bash

trim_env_whitespace() {
  local value="$1"
  value="${value#"${value%%[![:space:]]*}"}"
  value="${value%"${value##*[![:space:]]}"}"
  printf '%s' "${value}"
}

load_env_file() {
  local env_file="$1"
  local raw_line=""
  local normalized=""
  local key=""
  local value=""
  local trimmed_value=""
  local quote_char=""

  [[ -f "${env_file}" ]] || return 1

  while IFS= read -r raw_line || [[ -n "${raw_line}" ]]; do
    raw_line="${raw_line%$'\r'}"
    normalized="$(trim_env_whitespace "${raw_line}")"
    if [[ -z "${normalized}" || "${normalized:0:1}" == "#" ]]; then
      continue
    fi
    if [[ "${normalized}" == export\ * ]]; then
      normalized="${normalized#export }"
    fi
    if [[ "${normalized}" != *=* ]]; then
      continue
    fi

    key="$(trim_env_whitespace "${normalized%%=*}")"
    if [[ -z "${key}" ]]; then
      continue
    fi

    value="${normalized#*=}"
    trimmed_value="$(trim_env_whitespace "${value}")"
    if [[ ${#trimmed_value} -ge 2 ]]; then
      quote_char="${trimmed_value:0:1}"
      if [[ ( "${quote_char}" == "'" || "${quote_char}" == '"' ) && "${trimmed_value: -1}" == "${quote_char}" ]]; then
        value="${trimmed_value:1:${#trimmed_value}-2}"
      else
        value="${trimmed_value}"
      fi
    else
      value="${trimmed_value}"
    fi

    printf -v "${key}" '%s' "${value}"
    export "${key}"
  done < "${env_file}"
}