package auth

import (
	"errors"
	"html/template"
	"log"
)

var (
	// ErrInvalidLoginURI is returned when a Context is instantiated with a Config object that specifies a LoginURI that can't be parsed as a URL.
	ErrInvalidLoginURI = errors.New("invalid login URI")
	// ErrConfigNotInitialized is returned when a Context is instantiated with a Config object that hasn't had its Init function called.
	ErrConfigNotInitialized = errors.New("config not initialized")
)

// Config holds the configuration values necessary to run a server. A Config
// instance is the only way to instantiate a Context variable.
type Config struct {
	ClientStore   clientStore
	AuthCodeStore authorizationCodeStore
	ProfileStore  profileStore
	TokenStore    tokenStore
	SessionStore  sessionStore
	Template      *template.Template
	LoginURI      string
	iterations    int
	secureCookie  bool
}

// Init is a function that preps the Config object to be used for Context creation, setting variables
// that are determined at the beginning of program execution.
func (c *Config) Init() error {
	scheme, ok := passphraseSchemes[CurPassphraseScheme]
	if !ok {
		return ErrInvalidPassphraseScheme
	}
	var err error
	c.iterations, err = scheme.calculateIterations()
	if err != nil {
		return err
	}
	log.Printf("Generating passphrases with %d iterations...\n", c.iterations)
	return nil
}