package config

import (
	"fmt"

	"github.com/spf13/viper"
)

type ClientConfig struct {
	SecretHash string   `mapstructure:"secret_hash"`
	Exact      []string `mapstructure:"exact"`
	Wildcard   []string `mapstructure:"wildcard"`
}

type ServerConfig struct {
	BindAddress string    `mapstructure:"bind_address"`
	TLS         TLSConfig `mapstructure:"tls"`
}

type TLSConfig struct {
	Enabled  bool   `mapstructure:"enabled"`
	CertFile string `mapstructure:"cert_file"`
	KeyFile  string `mapstructure:"key_file"`
}

type HetznerConfig struct {
	APIToken     string `mapstructure:"api_token"`
	APITokenFile string `mapstructure:"api_token_file"`
}

type UpstreamConfig struct {
	Provider string        `mapstructure:"provider"`
	Hetzner  HetznerConfig `mapstructure:"hetzner"`
}

type Config struct {
	Server   ServerConfig            `mapstructure:"server"`
	Upstream UpstreamConfig          `mapstructure:"upstream"`
	Clients  map[string]ClientConfig `mapstructure:"clients"`
}

// LoadConfig reads the file at path (yaml, json, toml) into Config and validates it.
func LoadConfig(path string) (*Config, error) {
	v := viper.New()
	v.SetConfigFile(path)

	if err := v.ReadInConfig(); err != nil {
		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)
	}

	for name, client := range cfg.Clients {
		if len(client.Exact) == 0 && len(client.Wildcard) == 0 {
			return nil, fmt.Errorf("client %q must have at least one of exact or wildcard", name)
		}
	}

	return &cfg, nil
}