package toolbox

import (
	"errors"
	"net/url"
	"regexp"
	"strings"
	"time"

	"github.com/cloudtrust/keycloak-client/v3"
)

// IssuerManager provides URL according to a given context
type IssuerManager interface {
	GetOidcVerifierProvider(issuer string) (OidcVerifierProvider, error)
}

type issuerManager struct {
	domainToVerifier map[string]OidcVerifierProvider
}

func getProtocolAndDomain(URL string) string {
	var r = regexp.MustCompile(`^\w+:\/\/[^\/]+`)
	var match = r.FindStringSubmatch(URL)
	if match != nil {
		return strings.ToLower(match[0])
	}
	// Best effort: if not found return the whole input string
	return URL
}

// NewIssuerManager creates a new URLProvider
func NewIssuerManager(config keycloak.Config) (IssuerManager, error) {
	URLs := config.AddrTokenProvider
	// Use default values when clients are not initializing these values
	cacheTTL := config.CacheTTL
	if cacheTTL == 0 {
		cacheTTL = 15 * time.Minute
	}
	errTolerance := config.ErrorTolerance
	if errTolerance == 0 {
		errTolerance = time.Minute
	}

	var domainToVerifier = make(map[string]OidcVerifierProvider)

	for _, value := range strings.Split(URLs, " ") {
		uToken, err := url.Parse(value)
		if err != nil {
			return nil, err
		}
		verifier := NewVerifierCache(uToken, cacheTTL, errTolerance)
		domainToVerifier[getProtocolAndDomain(value)] = verifier
	}
	return &issuerManager{
		domainToVerifier: domainToVerifier,
	}, nil
}

func (im *issuerManager) GetOidcVerifierProvider(issuer string) (OidcVerifierProvider, error) {
	issuerDomain := getProtocolAndDomain(issuer)
	if verifier, ok := im.domainToVerifier[issuerDomain]; ok {
		return verifier, nil
	}
	return nil, errors.New("Unknown issuer")
}