package auth

import (
	"fmt"
	"strings"

	"github.com/rancher/types/apis/core/v1"
	"github.com/rancher/types/apis/management.cattle.io/v3"
	"github.com/rancher/types/config"
	"github.com/rancher/types/user"
	"github.com/sirupsen/logrus"
	v12 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/client-go/tools/cache"
)

type userLifecycle struct {
	prtb            v3.ProjectRoleTemplateBindingInterface
	crtb            v3.ClusterRoleTemplateBindingInterface
	grb             v3.GlobalRoleBindingInterface
	users           v3.UserInterface
	tokens          v3.TokenInterface
	namespaces      v1.NamespaceInterface
	namespaceLister v1.NamespaceLister
	secrets         v1.SecretInterface
	secretsLister   v1.SecretLister
	prtbLister      v3.ProjectRoleTemplateBindingLister
	crtbLister      v3.ClusterRoleTemplateBindingLister
	grbLister       v3.GlobalRoleBindingLister
	prtbIndexer     cache.Indexer
	crtbIndexer     cache.Indexer
	grbIndexer      cache.Indexer
	tokenIndexer    cache.Indexer
	userManager     user.Manager
}

const (
	crtbByUserRefKey  = "auth.management.cattle.io/crtb-by-user-ref"
	prtbByUserRefKey  = "auth.management.cattle.io/prtb-by-user-ref"
	grbByUserRefKey   = "auth.management.cattle.io/grb-by-user-ref"
	tokenByUserRefKey = "auth.management.cattle.io/token-by-user-ref"
	userController    = "mgmt-auth-users-controller"
)

func newUserLifecycle(management *config.ManagementContext) *userLifecycle {
	lfc := &userLifecycle{
		prtb:            management.Management.ProjectRoleTemplateBindings(""),
		crtb:            management.Management.ClusterRoleTemplateBindings(""),
		grb:             management.Management.GlobalRoleBindings(""),
		users:           management.Management.Users(""),
		tokens:          management.Management.Tokens(""),
		namespaces:      management.Core.Namespaces(""),
		secrets:         management.Core.Secrets(""),
		secretsLister:   management.Core.Secrets("").Controller().Lister(),
		prtbLister:      management.Management.ProjectRoleTemplateBindings("").Controller().Lister(),
		crtbLister:      management.Management.ClusterRoleTemplateBindings("").Controller().Lister(),
		grbLister:       management.Management.GlobalRoleBindings("").Controller().Lister(),
		namespaceLister: management.Core.Namespaces("").Controller().Lister(),
		userManager:     management.UserManager,
	}

	prtbInformer := management.Management.ProjectRoleTemplateBindings("").Controller().Informer()
	prtbInformer.AddIndexers(map[string]cache.IndexFunc{
		prtbByUserRefKey: prtbByUserRefFunc,
	})

	lfc.prtbIndexer = prtbInformer.GetIndexer()

	crtbInformer := management.Management.ClusterRoleTemplateBindings("").Controller().Informer()
	crtbInformer.AddIndexers(map[string]cache.IndexFunc{
		crtbByUserRefKey: crtbByUserRefFunc,
	})

	lfc.crtbIndexer = crtbInformer.GetIndexer()

	grbInformer := management.Management.GlobalRoleBindings("").Controller().Informer()
	grbInformer.AddIndexers(map[string]cache.IndexFunc{
		grbByUserRefKey: grbByUserRefFunc,
	})

	lfc.grbIndexer = grbInformer.GetIndexer()

	tokenInformer := management.Management.Tokens("").Controller().Informer()
	tokenInformer.AddIndexers(map[string]cache.IndexFunc{
		tokenByUserRefKey: tokenByUserRefFunc,
	})

	lfc.tokenIndexer = tokenInformer.GetIndexer()

	return lfc
}

func grbByUserRefFunc(obj interface{}) ([]string, error) {
	globalRoleBinding, ok := obj.(*v3.GlobalRoleBinding)
	if !ok {
		return []string{}, nil
	}

	return []string{globalRoleBinding.UserName}, nil
}

func prtbByUserRefFunc(obj interface{}) ([]string, error) {
	projectRoleBinding, ok := obj.(*v3.ProjectRoleTemplateBinding)
	if !ok || projectRoleBinding.UserName == "" {
		return []string{}, nil
	}

	return []string{projectRoleBinding.UserName}, nil
}

func crtbByUserRefFunc(obj interface{}) ([]string, error) {
	clusterRoleBinding, ok := obj.(*v3.ClusterRoleTemplateBinding)
	if !ok || clusterRoleBinding.UserName == "" {
		return []string{}, nil
	}

	return []string{clusterRoleBinding.UserName}, nil
}

func tokenByUserRefFunc(obj interface{}) ([]string, error) {
	token, ok := obj.(*v3.Token)
	if !ok {
		return []string{}, nil
	}

	return []string{token.UserID}, nil
}

func (l *userLifecycle) Create(user *v3.User) (runtime.Object, error) {
	var match = false
	for _, id := range user.PrincipalIDs {
		if strings.HasPrefix(id, "local://") {
			match = true
			break
		}
	}

	if !match {
		user.PrincipalIDs = append(user.PrincipalIDs, "local://"+user.Name)
	}

	// creatorIDAnn indicates it was created through the API, create the new
	// user bindings and add the annotation UserConditionInitialRolesPopulated
	if user.ObjectMeta.Annotations[creatorIDAnn] != "" {
		u, err := v3.UserConditionInitialRolesPopulated.DoUntilTrue(user, func() (runtime.Object, error) {
			err := l.userManager.CreateNewUserClusterRoleBinding(user.Name, user.UID)
			if err != nil {
				return nil, err
			}
			return user, nil
		})
		if err != nil {
			return nil, err
		}
		user = u.(*v3.User)
	}

	return user, nil
}

func (l *userLifecycle) Updated(user *v3.User) (runtime.Object, error) {
	err := l.userManager.CreateNewUserClusterRoleBinding(user.Name, user.UID)
	if err != nil {
		return nil, err
	}
	return user, nil
}

func (l *userLifecycle) Remove(user *v3.User) (runtime.Object, error) {
	clusterRoles, err := l.getCRTBByUserName(user.Name)
	if err != nil {
		return nil, err
	}

	err = l.deleteAllCRTB(clusterRoles)
	if err != nil {
		return nil, err
	}

	projectRoles, err := l.getPRTBByUserName(user.Name)
	if err != nil {
		return nil, err
	}

	err = l.deleteAllPRTB(projectRoles)
	if err != nil {
		return nil, err
	}

	globalRoles, err := l.getGRBByUserName(user.Name)
	if err != nil {
		return nil, err
	}

	err = l.deleteAllGRB(globalRoles)
	if err != nil {
		return nil, err
	}

	tokens, err := l.getTokensByUserName(user.Name)
	if err != nil {
		return nil, err
	}

	err = l.deleteAllTokens(tokens)
	if err != nil {
		return nil, err
	}

	err = l.deleteUserNamespace(user.Name)
	if err != nil {
		return nil, err
	}

	err = l.deleteUserSecret(user.Name)
	if err != nil {
		return nil, err
	}

	return user, nil
}

func (l *userLifecycle) getCRTBByUserName(username string) ([]*v3.ClusterRoleTemplateBinding, error) {
	obj, err := l.crtbIndexer.ByIndex(crtbByUserRefKey, username)
	if err != nil {
		return nil, fmt.Errorf("error getting cluster roles: %v", err)
	}

	var crtbs []*v3.ClusterRoleTemplateBinding
	for _, o := range obj {
		crtb, ok := o.(*v3.ClusterRoleTemplateBinding)
		if !ok {
			return nil, fmt.Errorf("error converting obj to cluster role template binding: %v", o)
		}

		crtbs = append(crtbs, crtb)
	}

	return crtbs, nil
}

func (l *userLifecycle) getPRTBByUserName(username string) ([]*v3.ProjectRoleTemplateBinding, error) {
	objs, err := l.prtbIndexer.ByIndex(prtbByUserRefKey, username)
	if err != nil {
		return nil, fmt.Errorf("error getting indexed project roles: %v", err)
	}

	var prtbs []*v3.ProjectRoleTemplateBinding
	for _, obj := range objs {
		prtb, ok := obj.(*v3.ProjectRoleTemplateBinding)
		if !ok {
			return nil, fmt.Errorf("could not convert obj to v3.ProjectRoleTemplateBinding")
		}

		prtbs = append(prtbs, prtb)
	}

	return prtbs, nil
}

func (l *userLifecycle) getGRBByUserName(username string) ([]*v3.GlobalRoleBinding, error) {
	objs, err := l.grbIndexer.ByIndex(grbByUserRefKey, username)
	if err != nil {
		return nil, fmt.Errorf("error getting indexed global roles: %v", err)
	}

	var grbs []*v3.GlobalRoleBinding
	for _, obj := range objs {
		grb, ok := obj.(*v3.GlobalRoleBinding)
		if !ok {
			return nil, fmt.Errorf("could not convert obj to v3.GlobalRoleBinding")
		}

		grbs = append(grbs, grb)
	}

	return grbs, nil
}

func (l *userLifecycle) getTokensByUserName(username string) ([]*v3.Token, error) {
	objs, err := l.tokenIndexer.ByIndex(tokenByUserRefKey, username)
	if err != nil {
		return nil, fmt.Errorf("error getting indexed tokens: %v", err)
	}

	var tokens []*v3.Token
	for _, obj := range objs {
		token, ok := obj.(*v3.Token)
		if !ok {
			return nil, fmt.Errorf("could not convert to *v3.Token: %v", obj)
		}

		tokens = append(tokens, token)
	}

	return tokens, nil
}

func (l *userLifecycle) deleteAllCRTB(crtbs []*v3.ClusterRoleTemplateBinding) error {
	for _, crtb := range crtbs {
		var err error
		if crtb.Namespace == "" {
			logrus.Infof("[%v] Deleting clusterRoleTemplateBinding %v for user %v", userController, crtb.Name, crtb.UserName)
			err = l.crtb.Delete(crtb.Name, &metav1.DeleteOptions{})
		} else {
			logrus.Infof("[%v] Deleting clusterRoleTemplateBinding %v for user %v", userController, crtb.Name, crtb.UserName)
			err = l.crtb.DeleteNamespaced(crtb.Namespace, crtb.Name, &metav1.DeleteOptions{})
		}
		if err != nil {
			return fmt.Errorf("error deleting cluster role: %v", err)
		}
	}

	return nil
}

func (l *userLifecycle) deleteAllPRTB(prtbs []*v3.ProjectRoleTemplateBinding) error {
	for _, prtb := range prtbs {
		var err error
		if prtb.Namespace == "" {
			logrus.Infof("[%v] Deleting projectRoleTemplateBinding %v for user %v", userController, prtb.Name, prtb.UserName)
			err = l.prtb.Delete(prtb.Name, &metav1.DeleteOptions{})
		} else {
			logrus.Infof("[%v] Deleting projectRoleTemplateBinding %v for user %v", userController, prtb.Name, prtb.UserName)
			err = l.prtb.DeleteNamespaced(prtb.Namespace, prtb.Name, &metav1.DeleteOptions{})
		}
		if err != nil {
			return fmt.Errorf("error deleting projet role: %v", err)
		}
	}

	return nil
}

func (l *userLifecycle) deleteAllGRB(grbs []*v3.GlobalRoleBinding) error {
	for _, grb := range grbs {
		var err error
		if grb.Namespace == "" {
			logrus.Infof("[%v] Deleting globalRoleBinding %v for user %v", userController, grb.Name, grb.UserName)
			err = l.grb.Delete(grb.Name, &metav1.DeleteOptions{})
		} else {
			logrus.Infof("[%v] Deleting globalRoleBinding %v for user %v", userController, grb.Name, grb.UserName)
			err = l.grb.DeleteNamespaced(grb.Namespace, grb.Name, &metav1.DeleteOptions{})
		}
		if err != nil {
			return fmt.Errorf("error deleting global role template %v: %v", grb.Name, err)

		}
	}

	return nil
}

func (l *userLifecycle) deleteAllTokens(tokens []*v3.Token) error {
	for _, token := range tokens {
		logrus.Infof("[%v] Deleting token %v for user %v", userController, token.Name, token.UserID)
		err := l.tokens.DeleteNamespaced(token.Namespace, token.Name, &metav1.DeleteOptions{})
		if err != nil {
			return fmt.Errorf("error deleting token: %v", err)
		}
	}

	return nil
}

func (l *userLifecycle) deleteUserNamespace(username string) error {
	namespace, err := l.namespaceLister.Get("", username)
	if err != nil {
		if errors.IsNotFound(err) {
			return nil // nothing to delete
		}

		return fmt.Errorf("error getting user namespace: %v", err)
	}

	if namespace.Status.Phase == v12.NamespaceTerminating {
		return nil // nothing to do namespace is already deleting
	}

	logrus.Infof("[%v] Deleting namespace backing user %v", userController, username)
	err = l.namespaces.Delete(username, &metav1.DeleteOptions{})
	if err != nil {
		return fmt.Errorf("error deleting user namespace: %v", err)
	}

	return nil
}

func (l *userLifecycle) deleteUserSecret(username string) error {
	_, err := l.secretsLister.Get("cattle-system", username+"-secret")
	if err != nil {
		if errors.IsNotFound(err) {
			return nil
		}
		return fmt.Errorf("error getting user secret: %v", err)
	}

	logrus.Infof("[%v] Deleting secret backing user %v", userController, username)
	return l.secrets.DeleteNamespaced("cattle-system", username+"-secret", &metav1.DeleteOptions{})
}