package config

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

type Config struct {
	Addr          string
	DatabaseURL   string
	RedisURL      string
	JWTSecret     []byte
	AdminUser     string
	AdminPassword string
	BooksDir      string
	CacheDir      string
	ScanInterval  time.Duration
	UploadMaxMB   int64
}

func Load() (*Config, error) {
	env := func(k, def string) string {
		if v := os.Getenv(k); v != "" {
			return v
		}
		return def
	}
	scanSec, err := strconv.Atoi(env("SCAN_INTERVAL_SEC", "60"))
	if err != nil {
		return nil, fmt.Errorf("SCAN_INTERVAL_SEC: %w", err)
	}
	uploadMB, err := strconv.ParseInt(env("UPLOAD_MAX_MB", "200"), 10, 64)
	if err != nil {
		return nil, fmt.Errorf("UPLOAD_MAX_MB: %w", err)
	}
	secret := os.Getenv("JWT_SECRET")
	if secret == "" {
		return nil, fmt.Errorf("JWT_SECRET required")
	}
	return &Config{
		Addr:          env("ADDR", ":8080"),
		DatabaseURL:   env("DATABASE_URL", ""),
		RedisURL:      env("REDIS_URL", ""),
		JWTSecret:     []byte(secret),
		AdminUser:     env("ADMIN_USER", ""),
		AdminPassword: env("ADMIN_PASSWORD", ""),
		BooksDir:      env("BOOKS_DIR", "/data/books"),
		CacheDir:      env("CACHE_DIR", "/data/cache"),
		ScanInterval:  time.Duration(scanSec) * time.Second,
		UploadMaxMB:   uploadMB,
	}, nil
}