package main

import (
	"errors"
	"os"
	"strconv"
)

func getEnvFallback(key string, fallback ...string) (string, error) {
	// Check for function fallback signature
	length := len(fallback)
	if length > 1 {
		return "", errors.New("Invalid signature: Too many fallback values provided!")
	}

	// Try to get environment variable
	value, exists := os.LookupEnv(key)
	if exists {
		return value, nil
	}

	// Try using fallback value instead
	if length == 1 {
		return fallback[0], nil
	} else if length == 0 {
		// No fallback value provided
		return "", errors.New("Panic: No fallback value provided!")
	}

	// Could not get environment variable
	return "", errors.New("Could not get environment variable: " + key)
}

func convertFallback(input string, fallback ...int) (int, error) {
	// Check for function fallback signature
	length := len(fallback)
	if length > 1 {
		return 0, errors.New("Invalid signature: Too many fallback values provided!")
	}

	// Try to convert input to int
	value, err := strconv.Atoi(input)
	if err == nil {
		return value, nil
	}

	// Try using fallback value instead
	if length == 1 {
		return fallback[0], nil
	} else if length == 0 {
		// No fallback value provided
		return 0, errors.New("Panic: No fallback value provided!")
	}

	// Could not convert input
	return 0, err
}