package config

import (
	"errors"
	"fmt"
	"os"
	"strconv"
	"time"
)

type Config struct {
	Env             string
	HTTPAddr        string
	DatabaseURL     string
	JWKSURL         string
	RequestTimeout  time.Duration
	ShutdownTimeout time.Duration
}

func Load() (Config, error) {
	cfg := Config{
		Env:             getenv("APP_ENV", "development"),
		HTTPAddr:        getenv("HTTP_ADDR", ":8080"),
		DatabaseURL:     os.Getenv("DATABASE_URL"),
		JWKSURL:         os.Getenv("JWKS_URL"),
		RequestTimeout:  getDuration("REQUEST_TIMEOUT", 10*time.Second),
		ShutdownTimeout: getDuration("SHUTDOWN_TIMEOUT", 10*time.Second),
	}

	if cfg.DatabaseURL == "" {
		return Config{}, errors.New("DATABASE_URL is required")
	}
	if cfg.JWKSURL == "" {
		return Config{}, errors.New("JWKS_URL is required")
	}
	return cfg, nil
}

func getenv(key, fallback string) string {
	if val := os.Getenv(key); val != "" {
		return val
	}
	return fallback
}

func getDuration(key string, fallback time.Duration) time.Duration {
	if val := os.Getenv(key); val != "" {
		parsed, err := time.ParseDuration(val)
		if err == nil {
			return parsed
		}
	}
	return fallback
}

func MustLoad() Config {
	cfg, err := Load()
	if err != nil {
		panic(fmt.Errorf("config load failed: %w", err))
	}
	return cfg
}

func GetBool(key string, fallback bool) bool {
	val := os.Getenv(key)
	if val == "" {
		return fallback
	}
	parsed, err := strconv.ParseBool(val)
	if err != nil {
		return fallback
	}
	return parsed
}