package config

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

type Config struct {
	ListenAddr   string
	FootageRoot  string
	DBPath       string
	AdminUser    string
	AdminPass    string
	SessionTTL   time.Duration
	ScanInterval time.Duration
}

func Load() (*Config, error) {
	sessionTTL, err := parseDurationEnv("SESSION_TTL", 24*time.Hour)
	if err != nil {
		return nil, err
	}

	scanInterval, err := parseDurationEnv("SCAN_INTERVAL", 5*time.Minute)
	if err != nil {
		return nil, err
	}

	return &Config{
		ListenAddr:   getEnv("LISTEN_ADDR", ":8080"),
		FootageRoot:  getEnv("FOOTAGE_ROOT", "/footage"),
		DBPath:       getEnv("DB_PATH", "/data/cammonitor.db"),
		AdminUser:    getEnv("ADMIN_USER", "admin"),
		AdminPass:    getEnv("ADMIN_PASS", "changeme"),
		SessionTTL:   sessionTTL,
		ScanInterval: scanInterval,
	}, nil
}

func getEnv(key, fallback string) string {
	value := os.Getenv(key)
	if value == "" {
		return fallback
	}
	return value
}

func parseDurationEnv(key string, fallback time.Duration) (time.Duration, error) {
	value := os.Getenv(key)
	if value == "" {
		return fallback, nil
	}

	duration, err := time.ParseDuration(value)
	if err != nil {
		return 0, fmt.Errorf("parse %s: %w", key, err)
	}
	return duration, nil
}