#!/usr/bin/env bash

load_env_defaults() {
  local env_file="${1:-.env}"

  if [[ ! -f "$env_file" ]]; then
    return 0
  fi

  while IFS= read -r line || [[ -n "$line" ]]; do
    if [[ "$line" =~ ^[[:space:]]*$ ]] || [[ "$line" =~ ^[[:space:]]*# ]]; then
      continue
    fi

    if [[ "$line" != *=* ]]; then
      continue
    fi

    local key="${line%%=*}"
    local value="${line#*=}"

    key="${key#"${key%%[![:space:]]*}"}"
    key="${key%"${key##*[![:space:]]}"}"
    value="${value#"${value%%[![:space:]]*}"}"
    value="${value%"${value##*[![:space:]]}"}"

    if [[ ! "$key" =~ ^[A-Za-z_][A-Za-z0-9_]*$ ]]; then
      continue
    fi

    if [[ -n "${!key+x}" ]]; then
      continue
    fi

    if [[ "$value" =~ ^\"(.*)\"$ ]]; then
      value="${BASH_REMATCH[1]}"
    elif [[ "$value" =~ ^\'(.*)\'$ ]]; then
      value="${BASH_REMATCH[1]}"
    fi

    export "$key=$value"
  done < "$env_file"
}