package ldap

import (
	"sync"

	ldap "github.com/vjeantet/ldapserver"
)

// connection is the part of the underlying server's client type that
// this bridge uses for state belonging to a connection rather than to
// a single request. That type is unexported, so it is reached through
// the message and abstracted here so tests can supply their own.
type connection interface {
	GetData() interface{}
	SetData(interface{})
}

// boundState is the per-connection record stored in the client's
// additional data, which releases it together with the connection.
type boundState struct {
	sync.Mutex
	bound bool
}

// messageConn returns the connection a request arrived on.
func messageConn(m *ldap.Message) connection {
	if m == nil || m.Client == nil {
		return nil
	}
	return m.Client
}

// connOf returns the connection for a request. It is a field so that
// tests can inject a connection without the server's unexported
// client type.
func (s *server) connOf(m *ldap.Message) connection {
	if s.conn == nil {
		return messageConn(m)
	}
	return s.conn(m)
}

// bound reports whether the request arrived on a connection that has
// already been authenticated.
func (s *server) bound(m *ldap.Message) bool {
	st := existingState(s.connOf(m))
	if st == nil {
		return false
	}
	st.Lock()
	defer st.Unlock()
	return st.bound
}

// markBound records that the connection has been authenticated.
func (s *server) markBound(m *ldap.Message) {
	c := s.connOf(m)
	if c == nil {
		return
	}
	if st := existingState(c); st != nil {
		st.Lock()
		defer st.Unlock()
		st.bound = true
		return
	}
	c.SetData(&boundState{bound: true})
}

// markUnbound clears the authentication state of a connection. RFC
// 4511 requires a failed bind to leave the connection unauthenticated
// so that a client cannot hold on to access it has lost.
func (s *server) markUnbound(m *ldap.Message) {
	st := existingState(s.connOf(m))
	if st == nil {
		return
	}
	st.Lock()
	defer st.Unlock()
	st.bound = false
}

func existingState(c connection) *boundState {
	if c == nil {
		return nil
	}
	st, _ := c.GetData().(*boundState)
	return st
}