go-socket/packages/httpRequest/hubs.go

package httpRequest

import (
	"context"
	"encoding/json"
	"net/http"
	"strings"
	"time"

	"go-socket/packages/convertions"
	"go-socket/packages/postgresql"

	"go-socket/packages/cache"
	"go-socket/packages/minio"
	"go-socket/packages/types"
	"go-socket/packages/wsServer"

	"github.com/google/uuid"
)

func haveHubUserPermission(u *types.HubUser, h *types.Hub, needed types.Permissions) (id uint8, has bool) {
	h.Mu.Lock()
	defer h.Mu.Unlock()
	for _, role := range h.Roles {
		if role == nil {
			continue
		}
		if !u.Roles.ContainsRoleId(role.Id) {
			continue
		}
		if (needed&role.Permissions) == needed && role.Id > id {
			id = role.Id
			has = true
		}
	}
	return id, has
}

func hubUserHighestRoleId(u *types.HubUser, h *types.Hub) (id uint8) {
	h.Mu.Lock()
	defer h.Mu.Unlock()

	for _, role := range h.Roles {
		if role == nil {
			continue
		}
		if !u.Roles.ContainsRoleId(role.Id) {
			continue
		}
		if role.Id > id {
			id = role.Id
		}
	}
	return id
}

func updateChannelCacheForSpecUserAndChannel(u *types.HubUser, c *types.HubChannel) {
	c.Mu.Lock()
	defer c.Mu.Unlock()
	if u == nil {
		delete(c.UsersCachedPermissions, c.Id)
		return
	}
	if u.Roles.DoesIntersect(c.RolesCanView) {
		c.UsersCachedPermissions[u.OriginalId] |= types.CachedUserCanView
	} else {
		c.UsersCachedPermissions[u.OriginalId] &^= types.CachedUserCanView
	}
	if u.Roles.DoesIntersect(c.RolesCanReadHistory) {
		c.UsersCachedPermissions[u.OriginalId] |= types.CachedUserCanReadHistory
	} else {
		c.UsersCachedPermissions[u.OriginalId] &^= types.CachedUserCanReadHistory
	}
	if u.Roles.DoesIntersect(c.RolesCanMessage) {
		c.UsersCachedPermissions[u.OriginalId] |= types.CachedUserCanMessage
	} else {
		c.UsersCachedPermissions[u.OriginalId] &^= types.CachedUserCanMessage
	}
}

func updateChannelCacheForSpecChannel(c *types.HubChannel, h *types.Hub) {
	h.Mu.RLock()
	defer h.Mu.RUnlock()
	for _, u := range h.Users {
		updateChannelCacheForSpecUserAndChannel(u, c)
	}
}

func updateChannelCacheForSpecUser(u *types.HubUser, h *types.Hub) {
	h.Mu.RLock()
	defer h.Mu.RUnlock()
	for _, c := range h.Channels {
		if c == nil {
			continue
		}
		updateChannelCacheForSpecUserAndChannel(u, c)
	}
}

func updateChannelCacheForSpecRole(r *types.HubRole, h *types.Hub) {
	h.Mu.RLock()
	var users []*types.HubUser
	for _, u := range h.Users {
		if u.Roles.ContainsRoleId(r.Id) {
			users = append(users, u)
		}
	}
	h.Mu.RUnlock()
	for _, u := range users {
		updateChannelCacheForSpecUser(u, h)
	}
}

func haveHubUserCachedPermissions(needed types.CachedUserPermissions, user *types.HubUser, channel *types.HubChannel) bool {
	channel.Mu.RLock()
	checkAgainst, ok := channel.UsersCachedPermissions[user.OriginalId]
	channel.Mu.RUnlock()
	if !ok || (needed&checkAgainst) != needed {
		return false
	}
	return true
}

func HandleHubCreate(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}

	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}

	hubName := request.FormValue("hub_name")
	if hubName == "" {
		http.Error(response, "hub name is required", http.StatusBadRequest)
		return
	}

	hub := types.NewHub()
	hub.Name = hubName
	hub.Color = types.RandomRgba()
	hub.Id = uuid.New()
	hub.Creator = user.Id
	hub.CreatedAt = time.Now()
	user.Hubs[hub.Id] = hub

	creator := types.NewHubUser()
	creator.OriginalId = user.Id
	creator.CreatedAt = hub.CreatedAt
	hub.Users[creator.OriginalId] = creator

	rootRole := &types.HubRole{
		Id:          types.HubBoundRolesMax,
		Permissions: types.PermissionAll(),
		Name:        "root",
		Color:       types.RandomRgba(),
		CreatedAt:   hub.CreatedAt,
	}
	hub.Roles[rootRole.Id] = rootRole
	creator.Roles.Add(rootRole.Id)

	memberRole := &types.HubRole{
		Id:        uint8(0),
		Name:      "member",
		Color:     types.RandomRgba(),
		CreatedAt: hub.CreatedAt,
	}
	hub.JoinRole = memberRole
	hub.Roles[memberRole.Id] = memberRole
	creator.Roles.Add(memberRole.Id)

	channel := types.NewHubChannel()
	channel.Name = "main channel"
	channel.Id = uuid.New()
	channel.Description = "The fist channel!"
	channel.CreatedAt = hub.CreatedAt
	channel.RolesCanMessage.Add(rootRole.Id)
	channel.RolesCanMessage.Add(memberRole.Id)
	channel.RolesCanView.Add(rootRole.Id)
	channel.RolesCanView.Add(memberRole.Id)
	channel.RolesCanReadHistory.Add(rootRole.Id)
	channel.RolesCanReadHistory.Add(memberRole.Id)
	channel.UsersCachedPermissions[creator.OriginalId] = types.CachedUserPermissionsAll
	channel.Position = 0
	hub.Channels[channel.Id] = channel

	cache.SaveHub(hub)
	err = postgresql.HubSave(ctx, hub)
	if err != nil {
		http.Error(response, "failed to save hub", http.StatusInternalServerError)
		return
	}
	err = postgresql.HubUserSave(ctx, hub.Id, creator)
	if err != nil {
		http.Error(response, "failed to save hub user", http.StatusInternalServerError)
		return
	}
	err = postgresql.HubRoleSave(ctx, hub.Id, rootRole)
	if err != nil {
		http.Error(response, "failed to save hub role", http.StatusInternalServerError)
		return
	}
	err = postgresql.HubRoleSave(ctx, hub.Id, memberRole)
	if err != nil {
		http.Error(response, "failed to save hub role", http.StatusInternalServerError)
		return
	}
	err = postgresql.HubChannelSave(ctx, hub.Id, channel)
	if err != nil {
		http.Error(response, "failed to save hub channel", http.StatusInternalServerError)
		return
	}

	response.WriteHeader(http.StatusCreated)
	response.Write([]byte(hub.Id.String()))
}

func HandleHubJoin(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	user, err := getUserByToken(ctx, request.Header.Get("token"))
	if err != nil {
		http.Error(response, "invalid token", http.StatusUnauthorized)
		return
	}
	hub, err := getHubByIdStr(ctx, request.Header.Get("hub_id"))
	if err != nil {
		http.Error(response, "invalid hub_id", http.StatusBadRequest)
		return
	}

	_, ok := hub.Users[user.Id]
	if ok {
		http.Error(response, "hub already joined", http.StatusBadRequest)
		return
	}

	user.Hubs[hub.Id] = hub
	hubUser := types.NewHubUser()
	hubUser.OriginalId = user.Id
	if hub.JoinRole != nil {
		hubUser.Roles.Add(hub.JoinRole.Id)
	}
	hubUser.CreatedAt = time.Now()
	hub.Users[hubUser.OriginalId] = hubUser
	updateChannelCacheForSpecUser(hubUser, hub)

	if err = postgresql.HubUserSave(ctx, hub.Id, hubUser); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusCreated)
}

func HandleHubMessage(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	user, hubUser, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	channel, err := getHubChannelIfValidWithResponseOnFail(ctx, response, hub, hubUser, request.Header.Get("channel_id"))
	if err != nil {
		return
	}

	if hubUser.IsMuted {
		http.Error(response, "muted", http.StatusForbidden)
		return
	}

	msgContent := request.FormValue("msg_content")
	attachedFile := request.FormValue("attached_file")

	if msgContent == "" && attachedFile == "" {
		http.Error(response, "empty msgContent", http.StatusBadRequest)
		return
	}

	if attachedFile != "" && !strings.HasPrefix(attachedFile, string(minio.HubChannelFilePrefix)+channel.Id.String()+"/") {
		http.Error(response, "invalid attachedFile", http.StatusBadRequest)
		return
	}

	channel.Mu.RLock()
	perms := channel.UsersCachedPermissions
	channel.Mu.RUnlock()

	msg := &types.Message{
		Id:           uuid.New(),
		AttachedFile: attachedFile,
		Content:      msgContent,
		Sender:       user.Id,
		Receiver:     channel.Id,
		CreatedAt:    time.Now(),
	}
	channel.AddMessageToBuff(msg)

	for permId, perm := range perms {
		if !perm.CanReadHistory() {
			continue
		}

		target, err := cache.GetUserById(permId)
		if err != nil {
			continue
		}
		wsServer.WsSendMessageCloseIfTimeout(target, msg)
	}
	response.WriteHeader(http.StatusCreated)
}

func HandleGetChannels(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	_, requestor, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	channels := make([]uuid.UUID, 0)
	hub.Mu.RLock()
	for _, channel := range hub.Channels {
		if channel == nil || !haveHubUserCachedPermissions(types.CachedUserCanView, requestor, channel) {
			continue
		}
		channels = append(channels, channel.Id)
	}
	hub.Mu.RUnlock()
	if len(channels) == 0 {
		response.WriteHeader(http.StatusNoContent)
		return
	}

	marshal, err := json.Marshal(channels)
	if err != nil {
		http.Error(response, "json error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusOK)
	response.Write(marshal)
}

func HandleGetHubUsers(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	_, _, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	users := make([]*types.HubUser, 0)
	hub.Mu.RLock()
	for _, user := range hub.Users {
		users = append(users, user)
	}
	hub.Mu.RUnlock()
	if len(users) == 0 {
		response.WriteHeader(http.StatusNoContent)
		return
	}

	marshal, err := json.Marshal(users)
	if err != nil {
		http.Error(response, "json error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusOK)
	response.Write(marshal)
}

func GetRoles(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	_, _, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	hub.Mu.RLock()
	roles := make([]*types.HubRole, 0)
	for _, role := range hub.Roles {
		if role == nil {
			continue
		}
		roles = append(roles, role)
	}
	hub.Mu.RUnlock()
	marshal, err := json.Marshal(roles)
	if err != nil {
		http.Error(response, "json error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusOK)
	response.Write(marshal)
}

func GetHubData(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	_, _, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	marshal, err := json.Marshal(hub)
	if err != nil {
		http.Error(response, "json error", http.StatusInternalServerError)
	}
	response.WriteHeader(http.StatusOK)
	response.Write(marshal)
}
func GetChannelData(response http.ResponseWriter, request *http.Request) {
	if !validCheckWithResponseOnFail(response, request, normal) {
		return
	}
	ctx := request.Context()
	_, _, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return
	}
	channelId, err := convertions.StringToUuid(request.FormValue("channel_id"))
	if err != nil {
		http.Error(response, "invalid channel_id", http.StatusBadRequest)
		return
	}
	hub.Mu.RLock()
	channel, ok := hub.Channels[channelId]
	hub.Mu.RUnlock()
	if !ok {
		http.Error(response, "no such channel", http.StatusNotFound)
		return
	}
	marshal, err := json.Marshal(channel)
	if err != nil {
		http.Error(response, "json error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusOK)
	response.Write(marshal)
}

func hubPermissionContext(response http.ResponseWriter, request *http.Request, rt bodyLimit, needed types.Permissions) (*types.HubUser, *types.Hub, context.Context, uint8, bool) {
	if !validCheckWithResponseOnFail(response, request, rt) {
		return nil, nil, nil, 0, false
	}
	ctx := request.Context()
	_, hubUser, hub, err := getHubUserIfValidWithResponseOnFail(ctx, response, request)
	if err != nil {
		return nil, nil, nil, 0, false
	}

	roleId, ok := haveHubUserPermission(hubUser, hub, needed)

	if !ok {
		http.Error(response, "", http.StatusForbidden)
		return nil, nil, nil, 0, false
	}
	return hubUser, hub, ctx, roleId, true
}

func HandleHubSetName(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSetHubName)
	if !ok {
		return
	}
	newName := request.FormValue("new_name")
	if newName == "" {
		http.Error(response, "empty name", http.StatusBadRequest)
		return
	}
	hub.Name = newName
	if err := postgresql.HubUpdate(ctx, hub, &types.HubUpdate{Name: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubSetColor(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSetHubColor)
	if !ok {
		return
	}
	color, err := convertions.StringToRgba(request.FormValue("new_color"))
	if err != nil {
		http.Error(response, "bad color", http.StatusBadRequest)
		return
	}
	hub.Color = color
	if err = postgresql.HubUpdate(ctx, hub, &types.HubUpdate{Color: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubRemove(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionRemoveHub)
	if !ok {
		return
	}
	if err := postgresql.HubDelete(ctx, hub.Id); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	cache.DeleteHub(hub)
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubToggleUserColorAllowed(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSetUserColorAllowed)
	if !ok {
		return
	}
	hub.UserColorAllowed = !hub.UserColorAllowed
	if err := postgresql.HubUpdate(ctx, hub, &types.HubUpdate{UserColorAllowed: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleSetHubJoinRole(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSetHubJoinRole)
	if !ok {
		return
	}
	newRoleId, err := convertions.StringToUint8(request.FormValue("new_role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	newRole := hub.Roles[newRoleId]
	if newRole == nil {
		http.Error(response, "bad role_id", http.StatusNotFound)
		return
	}
	hub.JoinRole = newRole
	if err = postgresql.HubUpdate(ctx, hub, &types.HubUpdate{JoinRole: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubUserRemove(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionRemoveUser)
	if !ok {
		return
	}
	targetId, err := convertions.StringToUuid(request.FormValue("target_id"))
	if err != nil {
		http.Error(response, "bad target_id", http.StatusBadRequest)
		return
	}
	hub.Mu.RLock()
	hubTarget, exists := hub.Users[targetId]
	hub.Mu.RUnlock()
	if !exists {
		http.Error(response, "user not found", http.StatusNotFound)
		return
	}

	if usedRoleId <= hubUserHighestRoleId(hubTarget, hub) {
		http.Error(response, "target higher in hierarchy", http.StatusForbidden)
		return
	}

	target, err := cache.GetUserById(targetId)
	if err != nil {
		http.Error(response, "target not found", http.StatusInternalServerError)
		return
	}
	target.Mu.Lock()
	delete(target.Hubs, hub.Id)
	target.Mu.Unlock()

	if err = postgresql.HubUserDelete(ctx, hub.Id, targetId); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	hub.Mu.Lock()
	delete(hub.Users, targetId)
	hub.Mu.Unlock()
	updateChannelCacheForSpecUser(hubTarget, hub)
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubRenameUser(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionRenameUser)
	if !ok {
		return
	}
	newName := request.FormValue("new_name")
	targetId, err := convertions.StringToUuid(request.FormValue("target_id"))
	if err != nil {
		http.Error(response, "bad target_id", http.StatusBadRequest)
		return
	}
	hub.Mu.RLock()
	target, exists := hub.Users[targetId]
	hub.Mu.RUnlock()
	if !exists {
		http.Error(response, "user not found", http.StatusNotFound)
		return
	}

	if usedRoleId <= hubUserHighestRoleId(target, hub) {
		http.Error(response, "target higher in hierarchy", http.StatusForbidden)
		return
	}
	target.Name = newName
	if err = postgresql.HubUserUpdate(ctx, hub.Id, target, &types.HubUserUpdate{Name: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubRenameSelf(response http.ResponseWriter, request *http.Request) {
	requestor, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSelfRename)
	if !ok {
		return
	}
	requestor.Name = request.FormValue("new_name")
	if err := postgresql.HubUserUpdate(ctx, hub.Id, requestor, &types.HubUserUpdate{Name: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubToggleMuteUser(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionMuteUser)
	if !ok {
		return
	}
	targetId, err := convertions.StringToUuid(request.FormValue("target_id"))
	if err != nil {
		http.Error(response, "bad target_id", http.StatusBadRequest)
		return
	}
	hub.Mu.RLock()
	target, exists := hub.Users[targetId]
	hub.Mu.RUnlock()
	if !exists {
		http.Error(response, "user not found", http.StatusNotFound)
		return
	}

	if usedRoleId <= hubUserHighestRoleId(target, hub) {
		http.Error(response, "target higher in hierarchy", http.StatusForbidden)
		return
	}
	target.IsMuted = !target.IsMuted
	if err = postgresql.HubUserUpdate(ctx, hub.Id, target, &types.HubUserUpdate{IsMuted: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubUserAddRole(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionUserAddRole)
	if !ok {
		return
	}
	targetId, err := convertions.StringToUuid(request.FormValue("target_id"))
	if err != nil {
		http.Error(response, "bad target_id", http.StatusBadRequest)
		return
	}
	roleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	if roleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}

	hub.Mu.RLock()
	target, ok := hub.Users[targetId]
	role := hub.Roles[roleId]
	hub.Mu.RUnlock()
	if !ok {
		http.Error(response, "user not found", http.StatusNotFound)
		return
	}
	if role == nil {
		http.Error(response, "role not found", http.StatusNotFound)
		return
	}
	target.Roles.Add(roleId)
	updateChannelCacheForSpecUser(target, hub)
	if err = postgresql.HubUserUpdate(ctx, hub.Id, target, &types.HubUserUpdate{Roles: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubUserRemoveRole(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionUserRemoveRole)
	if !ok {
		return
	}
	targetId, err := convertions.StringToUuid(request.FormValue("target_id"))
	if err != nil {
		http.Error(response, "bad target_id", http.StatusBadRequest)
		return
	}
	roleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	if roleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}

	hub.Mu.RLock()
	target, ok := hub.Users[targetId]
	hub.Mu.RUnlock()
	if !ok {
		http.Error(response, "user not found", http.StatusNotFound)
		return
	}
	target.Roles.Remove(roleId)
	updateChannelCacheForSpecUser(target, hub)
	if err = postgresql.HubUserUpdate(ctx, hub.Id, target, &types.HubUserUpdate{Roles: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleHubCreateRole(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionCreateRole)
	if !ok {
		return
	}
	name := request.FormValue("name")
	if name == "" {
		http.Error(response, "empty name", http.StatusBadRequest)
		return
	}
	hub.Mu.Lock()
	var freeId uint8
	found := false
	for i := uint8(1); i < types.HubBoundRolesMax; i++ {
		if hub.Roles[i] == nil && usedRoleId > i {
			freeId = i
			found = true
			break
		}
	}
	if !found {
		hub.Mu.Unlock()
		http.Error(response, "no role slots available", http.StatusConflict)
		return
	}
	newRole := &types.HubRole{
		Id:        freeId,
		Name:      name,
		Color:     types.RandomRgba(),
		CreatedAt: time.Now(),
	}
	hub.Roles[freeId] = newRole
	hub.Mu.Unlock()
	if err := postgresql.HubRoleSave(ctx, hub.Id, newRole); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusCreated)
}

func HandleHubRemoveRole(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionRemoveRole)
	if !ok {
		return
	}
	targetRoleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	if targetRoleId == 0 {
		http.Error(response, "cannot remove root role", http.StatusForbidden)
		return
	}
	if targetRoleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}

	hub.Mu.Lock()
	if hub.Roles[targetRoleId] == nil {
		hub.Mu.Unlock()
		http.Error(response, "role not found", http.StatusNotFound)
		return
	}
	hub.Roles[targetRoleId] = nil
	hub.Mu.Unlock()
	if err := postgresql.HubRoleDelete(ctx, hub.Id, targetRoleId); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleRoleSetName(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionSetRoleName)
	if !ok {
		return
	}
	roleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	if roleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}
	newName := request.FormValue("new_name")
	if newName == "" {
		http.Error(response, "name empty", http.StatusBadRequest)
		return
	}

	hub.Mu.Lock()
	role := hub.Roles[roleId]
	if role == nil {
		hub.Mu.Unlock()
		http.Error(response, "no such role", http.StatusNotFound)
		return
	}
	role.Name = newName
	hub.Mu.Unlock()
	if err = postgresql.HubRoleUpdate(ctx, hub.Id, role, &types.HubRoleUpdate{Name: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleRoleSetColor(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionSetRoleColor)
	if !ok {
		return
	}
	roleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	if roleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}
	color, err := convertions.StringToRgba(request.FormValue("new_color"))
	if err != nil {
		http.Error(response, "invalid new_color", http.StatusBadRequest)
		return
	}

	hub.Mu.Lock()
	role := hub.Roles[roleId]
	if role == nil {
		hub.Mu.Unlock()
		http.Error(response, "no such role", http.StatusNotFound)
		return
	}
	role.Color = color
	hub.Mu.Unlock()
	if err = postgresql.HubRoleUpdate(ctx, hub.Id, role, &types.HubRoleUpdate{Color: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleRoleSetPermissions(response http.ResponseWriter, request *http.Request) {
	requestor, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionSetRolePermissions)
	if !ok {
		return
	}
	targetRoleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "bad role_id", http.StatusBadRequest)
		return
	}
	if targetRoleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}
	hub.Mu.Lock()
	targetRole := hub.Roles[targetRoleId]
	hub.Mu.Unlock()
	if targetRole == nil {
		http.Error(response, "no such role", http.StatusNotFound)
		return
	}

	madeChange := false
	query := request.URL.Query()
	for key, values := range query {
		permission, ok := types.PermissionLookup(key)
		if !ok {
			continue
		}
		permRoleId, ok := haveHubUserPermission(requestor, hub, permission)
		if !ok {
			http.Error(response, "permission needed: "+key, http.StatusNotFound)
		}
		if permRoleId <= targetRoleId {
			http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
			return
		}

		if convertions.StringToBool(values[0]) {
			if !targetRole.Permissions.Has(permission) {
				madeChange = true
				targetRole.Permissions.Grant(permission)
			}
		} else {
			if targetRole.Permissions.Has(permission) {
				madeChange = true
				targetRole.Permissions.Revoke(permission)
			}
		}
	}

	if !madeChange {
		response.WriteHeader(http.StatusNoContent)
		response.Write([]byte("no changes made"))
		return
	}

	updateChannelCacheForSpecRole(targetRole, hub)
	if err := postgresql.HubRoleUpdate(ctx, hub.Id, targetRole, &types.HubRoleUpdate{Permissions: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleRoleSelfRemove(response http.ResponseWriter, request *http.Request) {
	requestor, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionUserSelfRoleRemove)
	if !ok {
		return
	}
	requestor.Roles.Remove(usedRoleId)
	updateChannelCacheForSpecUser(requestor, hub)
	if err := postgresql.HubUserUpdate(ctx, hub.Id, requestor, &types.HubUserUpdate{Roles: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleChannelCreate(response http.ResponseWriter, request *http.Request) {
	requestor, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, types.PermissionCreateChannel)
	if !ok {
		return
	}
	name := request.FormValue("name")
	if name == "" { // TODO think about some restriction to not be too big
		http.Error(response, "name empty", http.StatusBadRequest)
		return
	}

	newHubChannel := types.NewHubChannel()
	newHubChannel.Name = name
	newHubChannel.Id = uuid.New()
	newHubChannel.CreatedAt = time.Now()

	newHubChannel.RolesCanView.Add(usedRoleId)
	newHubChannel.RolesCanMessage.Add(usedRoleId)
	newHubChannel.RolesCanReadHistory.Add(usedRoleId)

	if requestor.Roles.ContainsRoleId(types.HubBoundRolesMax) {
		newHubChannel.RolesCanView.Add(types.HubBoundRolesMax)
		newHubChannel.RolesCanMessage.Add(types.HubBoundRolesMax)
		newHubChannel.RolesCanReadHistory.Add(types.HubBoundRolesMax)
	}
	hub.Mu.Lock()
	usedPositions := make(map[uint8]bool, len(hub.Channels))
	for _, ch := range hub.Channels {
		usedPositions[ch.Position] = true
	}
	var position uint8
	for usedPositions[position] {
		position++
	}
	newHubChannel.Position = position
	hub.Channels[newHubChannel.Id] = newHubChannel
	hub.Mu.Unlock()

	updateChannelCacheForSpecChannel(newHubChannel, hub)
	if err := postgresql.HubChannelSave(ctx, hub.Id, newHubChannel); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleChannelRemove(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionRemoveChannel)
	if !ok {
		return
	}
	channelId, err := convertions.StringToUuid(request.FormValue("channel_id"))
	if err != nil {
		http.Error(response, "invalid channel_id", http.StatusBadRequest)
		return
	}

	hub.Mu.Lock()
	if _, ok = hub.Channels[channelId]; !ok {
		hub.Mu.Unlock()
		http.Error(response, "no such channel", http.StatusNotFound)
		return
	}
	delete(hub.Channels, channelId)
	hub.Mu.Unlock()
	if err = postgresql.HubChannelDelete(ctx, channelId); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}
func HandleChannelSetName(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSetChannelName)
	if !ok {
		return
	}
	newName := request.FormValue("new_name")
	if newName == "" {
		http.Error(response, "newname empty", http.StatusBadRequest)
		return
	}
	channelId, err := convertions.StringToUuid(request.FormValue("channel_id"))
	if err != nil {
		http.Error(response, "invalid channel_id", http.StatusBadRequest)
		return
	}

	hub.Mu.Lock()
	channel, ok := hub.Channels[channelId]
	if !ok {
		hub.Mu.Unlock()
		http.Error(response, "no such channel", http.StatusNotFound)
		return
	}
	channel.Name = newName
	hub.Mu.Unlock()
	if err = postgresql.HubChannelUpdate(ctx, channel, &types.HubChannelUpdate{Name: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleChannelSetDescription(response http.ResponseWriter, request *http.Request) {
	_, hub, ctx, _, ok := hubPermissionContext(response, request, normal, types.PermissionSetChannelDescription)
	if !ok {
		return
	}
	newDescription := request.FormValue("description")
	channelId, err := convertions.StringToUuid(request.FormValue("channel_id"))
	if err != nil {
		http.Error(response, "invalid channel_id", http.StatusBadRequest)
		return
	}

	hub.Mu.Lock()
	channel, ok := hub.Channels[channelId]
	if !ok {
		hub.Mu.Unlock()
		http.Error(response, "no such channel", http.StatusNotFound)
		return
	}
	channel.Description = newDescription
	hub.Mu.Unlock()
	if err = postgresql.HubChannelUpdate(ctx, channel, &types.HubChannelUpdate{Description: true}); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func handleChannelRolePermission(response http.ResponseWriter, request *http.Request, perm types.Permissions, updateList *types.HubChannelUpdate, modify func(*types.HubChannel, uint8, bool)) {
	_, hub, ctx, usedRoleId, ok := hubPermissionContext(response, request, normal, perm)
	if !ok {
		return
	}
	channelId, err := convertions.StringToUuid(request.FormValue("channel_id"))
	if err != nil {
		http.Error(response, "invalid channel_id", http.StatusBadRequest)
		return
	}
	roleId, err := convertions.StringToUint8(request.FormValue("role_id"))
	if err != nil {
		http.Error(response, "invalid role_id", http.StatusBadRequest)
		return
	}
	if roleId > usedRoleId {
		http.Error(response, "target role higher in hierarchy", http.StatusForbidden)
		return
	}
	allow := convertions.StringToBool(request.URL.Query().Get("allow"))

	hub.Mu.Lock()
	channel, ok := hub.Channels[channelId]
	if !ok {
		hub.Mu.Unlock()
		http.Error(response, "channel not found", http.StatusNotFound)
		return
	}
	modify(channel, roleId, allow)
	hub.Mu.Unlock()

	updateChannelCacheForSpecChannel(channel, hub)
	if err = postgresql.HubChannelUpdate(ctx, channel, updateList); err != nil {
		http.Error(response, "db error", http.StatusInternalServerError)
		return
	}
	response.WriteHeader(http.StatusAccepted)
}

func HandleChannelSetPermittedVisibleRole(response http.ResponseWriter, request *http.Request) {
	handleChannelRolePermission(response, request, types.PermissionSetChannelPermittedVisibleRoles, &types.HubChannelUpdate{RolesCanView: true}, func(c *types.HubChannel, roleId uint8, allow bool) {
		if allow {
			c.RolesCanView.Add(roleId)
		} else {
			c.RolesCanView.Remove(roleId)
		}
	})
}

func HandleChannelSetPermittedSendRole(response http.ResponseWriter, request *http.Request) {
	handleChannelRolePermission(response, request, types.PermissionSetChannelPermittedSendMessageRoles, &types.HubChannelUpdate{RolesCanMessage: true}, func(c *types.HubChannel, roleId uint8, allow bool) {
		if allow {
			c.RolesCanMessage.Add(roleId)
		} else {
			c.RolesCanMessage.Remove(roleId)
		}
	})
}

func HandleChannelSetPermittedHistoryRole(response http.ResponseWriter, request *http.Request) {
	handleChannelRolePermission(response, request, types.PermissionSetChannelPermittedReadHistoryRoles, &types.HubChannelUpdate{RolesCanReadHistory: true}, func(c *types.HubChannel, roleId uint8, allow bool) {
		if allow {
			c.RolesCanReadHistory.Add(roleId)
		} else {
			c.RolesCanReadHistory.Remove(roleId)
		}
	})
}