package internal

import (
	"fmt"
	"net/url"
	"os"
)

const (
	serviceUser = "salty"

	// InvalidConfigValue is the constant value for invalid config values
	// which must be changed for production configurations before successful
	// startup
	InvalidConfigValue = "INVALID CONFIG VALUE - PLEASE CHANGE THIS VALUE"

	// DefaultDebug is the default debug mode
	DefaultDebug = false

	// DefaultTLS is the default for whether to enable TLS
	DefaultTLS = false

	// DefaultTLSKey is the default path to a TLS private key (if blank uses Let's Encrypt)
	DefaultTLSKey = ""

	// DefaultTLSCert is the default path to a TLS certificate (if blank uses Let's Encrypt)
	DefaultTLSCert = ""

	// DefaultData is the default data directory for storage
	DefaultData = "./data"

	// DefaultStore is the default data store used for accounts, sessions, etc
	DefaultStore = "bitcask://data/saltyim.db"

	// DefaultBaseURL is the default Base URL for the server
	DefaultBaseURL = "https://salty." + DefaultPrimaryDomain

	// DefaultPrimaryDomain is the default primary domain delegated to this broker
	DefaultPrimaryDomain = "home.arpa"

	// DefaultAdminUser is the default publickye to grant admin privileges to
	DefaultAdminUser = ""

	// DefaultSupportEmail is the default email of the admin user used in support requests
	DefaultSupportEmail = "support@" + DefaultPrimaryDomain
)

func NewConfig() *Config {
	return &Config{
		Debug: DefaultDebug,
		Store: DefaultStore,

		BaseURL:       DefaultBaseURL,
		PrimaryDomain: DefaultPrimaryDomain,

		AdminUser:    DefaultAdminUser,
		SupportEmail: DefaultSupportEmail,
	}
}

// Option is a function that takes a config struct and modifies it
type Option func(*Config) error

// WithDebug sets the debug mode lfag
func WithDebug(debug bool) Option {
	return func(cfg *Config) error {
		cfg.Debug = debug
		return nil
	}
}

// WithTLS sets the tls flag
func WithTLS(tls bool) Option {
	return func(cfg *Config) error {
		cfg.TLS = tls
		return nil
	}
}

// WithTLSKey sets the path to a TLS private key
func WithTLSKey(tlsKey string) Option {
	return func(cfg *Config) error {
		cfg.TLSKey = tlsKey
		return nil
	}
}

// WithTLSCert sets the path to a TLS certificate
func WithTLSCert(tlsCert string) Option {
	return func(cfg *Config) error {
		cfg.TLSCert = tlsCert
		return nil
	}
}

// WithData sets the data directory to use for storage
func WithData(data string) Option {
	return func(cfg *Config) error {
		if err := os.MkdirAll(data, 0755); err != nil {
			return fmt.Errorf("error creating data directory %s: %w", data, err)
		}
		cfg.Data = data
		return nil
	}
}

// WithStore sets the store to use for accounts, sessions, etc.
func WithStore(store string) Option {
	return func(cfg *Config) error {
		cfg.Store = store
		return nil
	}
}

// WithBaseURL sets the Base URL used for constructing feed URLs
func WithBaseURL(baseURL string) Option {
	return func(cfg *Config) error {
		u, err := url.Parse(baseURL)
		if err != nil {
			return err
		}
		cfg.BaseURL = baseURL
		if baseURL != DefaultBaseURL {
			cfg.BrokerURI = baseURL
		}

		cfg.baseURL = u
		return nil
	}
}

// WithPrimaryDomain sets the Primary Domain this broker is delegated for
func WithPrimaryDomain(primaryDomain string) Option {
	return func(cfg *Config) error {
		cfg.PrimaryDomain = primaryDomain
		return nil
	}
}

// WithAdminUser sets the Admin user used for granting special features to
func WithAdminUser(adminUser string) Option {
	return func(cfg *Config) error {
		cfg.AdminUser = adminUser
		return nil
	}
}

// WithSupportEmail sets the Support email used to contact the operator of this broker
func WithSupportEmail(supportEmail string) Option {
	return func(cfg *Config) error {
		cfg.SupportEmail = supportEmail
		return nil
	}
}