package authentication

import (
	"crypto/tls"
	"net/mail"
	"time"

	"github.com/go-ldap/ldap/v3"
	"golang.org/x/text/encoding/unicode"
)

// LDAPClientFactory an interface of factory of LDAP clients.
type LDAPClientFactory interface {
	DialURL(addr string, opts ...ldap.DialOpt) (client LDAPClient, err error)
}

// LDAPClient is a cut down version of the ldap.Client interface with just the methods we use.
//
// Methods added to this interface that have a direct correlation with one from ldap.Client should have the same signature.
type LDAPClient interface {
	Start()
	Close()
	IsClosing() bool
	SetTimeout(timeout time.Duration)

	TLSConnectionState() (state tls.ConnectionState, ok bool)
	StartTLS(config *tls.Config) (err error)

	Unbind() (err error)
	Bind(username, password string) (err error)
	SimpleBind(request *ldap.SimpleBindRequest) (result *ldap.SimpleBindResult, err error)
	MD5Bind(host string, username string, password string) (err error)
	DigestMD5Bind(request *ldap.DigestMD5BindRequest) (result *ldap.DigestMD5BindResult, err error)
	UnauthenticatedBind(username string) (err error)
	ExternalBind() (err error)
	NTLMBind(domain string, username string, password string) (err error)
	NTLMUnauthenticatedBind(domain string, username string) (err error)
	NTLMBindWithHash(domain string, username string, hash string) (err error)
	NTLMChallengeBind(request *ldap.NTLMBindRequest) (result *ldap.NTLMBindResult, err error)

	Modify(request *ldap.ModifyRequest) (err error)
	ModifyWithResult(request *ldap.ModifyRequest) (result *ldap.ModifyResult, err error)
	ModifyDN(m *ldap.ModifyDNRequest) (err error)
	PasswordModify(request *ldap.PasswordModifyRequest) (result *ldap.PasswordModifyResult, err error)

	Add(request *ldap.AddRequest) (err error)
	Del(request *ldap.DelRequest) (err error)

	Search(request *ldap.SearchRequest) (result *ldap.SearchResult, err error)
	SearchWithPaging(request *ldap.SearchRequest, pagingSize uint32) (result *ldap.SearchResult, err error)
	Compare(dn string, attribute string, value string) (same bool, err error)

	WhoAmI(controls []ldap.Control) (result *ldap.WhoAmIResult, err error)
}

// UserDetails represent the details retrieved for a given user.
type UserDetails struct {
	Username    string
	DisplayName string
	Emails      []string
	Groups      []string
}

// Addresses returns the Emails []string as []mail.Address formatted with DisplayName as the Name attribute.
func (d UserDetails) Addresses() (addresses []mail.Address) {
	if len(d.Emails) == 0 {
		return nil
	}

	addresses = make([]mail.Address, len(d.Emails))

	for i, email := range d.Emails {
		addresses[i] = mail.Address{
			Name:    d.DisplayName,
			Address: email,
		}
	}

	return addresses
}

type ldapUserProfile struct {
	DN          string
	Emails      []string
	DisplayName string
	Username    string
}

// LDAPSupportedFeatures represents features which a server may support which are implemented in code.
type LDAPSupportedFeatures struct {
	Extensions   LDAPSupportedExtensions
	ControlTypes LDAPSupportedControlTypes
}

// LDAPSupportedExtensions represents extensions which a server may support which are implemented in code.
type LDAPSupportedExtensions struct {
	TLS           bool
	PwdModifyExOp bool
}

// LDAPSupportedControlTypes represents control types which a server may support which are implemented in code.
type LDAPSupportedControlTypes struct {
	MsftPwdPolHints           bool
	MsftPwdPolHintsDeprecated bool
}

var utf16LittleEndian = unicode.UTF16(unicode.LittleEndian, unicode.IgnoreBOM)