package config

import (
	"fmt"
	"os"
	"path/filepath"

	"github.com/spf13/viper"
)

type Config struct {
	NetBox   NetBoxConfig   `mapstructure:"netbox"`
	Resolver ResolverConfig `mapstructure:"resolver"`
	Cache    CacheConfig    `mapstructure:"cache"`
	SSH      SSHConfig      `mapstructure:"ssh"`
}

type NetBoxConfig struct {
	URL   string `mapstructure:"url"`
	Token string `mapstructure:"token"`
}

type ResolverConfig struct {
	Strategies        []string `mapstructure:"strategies"`
	ManagementSubnets []string `mapstructure:"management_subnets"`
	InterfaceName     string   `mapstructure:"interface_name"`
}

type CacheConfig struct {
	TTL  int    `mapstructure:"ttl"`
	Path string `mapstructure:"path"`
}

type SSHConfig struct {
	DefaultUser string `mapstructure:"default_user"`
}

func Load() (*Config, error) {
	v := viper.New()

	v.SetDefault("resolver.strategies", []string{"management_subnet", "primary_ip"})
	v.SetDefault("resolver.management_subnets", []string{})
	v.SetDefault("cache.ttl", 3600)

	configDir, err := os.UserConfigDir()
	if err == nil {
		v.SetConfigName("netssh")
		v.SetConfigType("yaml")
		v.AddConfigPath(filepath.Join(configDir))
		v.AddConfigPath(".")
	}

	v.SetEnvPrefix("NETSSH")
	v.AutomaticEnv()

	if err := v.ReadInConfig(); err != nil {
		if _, ok := err.(viper.ConfigFileNotFoundError); !ok {
			return nil, fmt.Errorf("reading config: %w", err)
		}
	}

	var cfg Config
	if err := v.Unmarshal(&cfg); err != nil {
		return nil, fmt.Errorf("parsing config: %w", err)
	}

	if cfg.Cache.Path == "" {
		cacheDir, err := os.UserCacheDir()
		if err != nil {
			cacheDir = filepath.Join(os.Getenv("HOME"), ".cache")
		}
		cfg.Cache.Path = filepath.Join(cacheDir, "netssh", "hosts.json")
	}

	return &cfg, nil
}