package config

import (
	"log"
	"os"
)

// Config holds application configuration loaded from the environment.
type Config struct {
	DatabaseURL string
	Port        string
	UsersFile   string
	JWTSecret   string
}

// Load reads configuration from environment variables.
// DATABASE_URL is required (no silent default — fails fast if missing).
// PORT defaults to "3000".
// USERS_FILE defaults to "users.env".
// JWT_SECRET is required.
func Load() *Config {
	dbURL := os.Getenv("DATABASE_URL")
	if dbURL == "" {
		log.Fatal("DATABASE_URL environment variable is required but not set. " +
			"Copy .env.example to .env and set the correct value.")
	}

	jwtSecret := os.Getenv("JWT_SECRET")
	if jwtSecret == "" {
		log.Fatal("JWT_SECRET environment variable is required but not set.")
	}

	port := os.Getenv("PORT")
	if port == "" {
		port = "3000"
	}

	usersFile := os.Getenv("USERS_FILE")
	if usersFile == "" {
		usersFile = "users.env"
	}

	return &Config{
		DatabaseURL: dbURL,
		Port:        port,
		UsersFile:   usersFile,
		JWTSecret:   jwtSecret,
	}
}