MM-10182 & MM-10183: Adds channel scheme and team scheme API endpoint. (#8680)

* MM-10183: Adds channel scheme API endpoint.

MM-10182: Adds team scheme API endpoint.

MM-10182_3: Switch from scheme_id in path to body.

* MM-10182/MM-10183: Changes path from 'schemes' to 'scheme'.

* MM-10182: Fix merge error.

api4/channel.go

@@ -15,6 +15,7 @@ func (api *API) InitChannel() {
 	api.BaseRoutes.Channels.Handle("/direct", api.ApiSessionRequired(createDirectChannel)).Methods("POST")
 	api.BaseRoutes.Channels.Handle("/group", api.ApiSessionRequired(createGroupChannel)).Methods("POST")
 	api.BaseRoutes.Channels.Handle("/members/{user_id:[A-Za-z0-9]+}/view", api.ApiSessionRequired(viewChannel)).Methods("POST")
+	api.BaseRoutes.Channels.Handle("/{channel_id:[A-Za-z0-9]+}/scheme", api.ApiSessionRequired(updateChannelScheme)).Methods("PUT")
 
 	api.BaseRoutes.ChannelsForTeam.Handle("", api.ApiSessionRequired(getPublicChannelsForTeam)).Methods("GET")
 	api.BaseRoutes.ChannelsForTeam.Handle("/deleted", api.ApiSessionRequired(getDeletedChannelsForTeam)).Methods("GET")
@@ -948,3 +949,53 @@ func removeChannelMember(c *Context, w http.ResponseWriter, r *http.Request) {
 
 	ReturnStatusOK(w)
 }
+
+func updateChannelScheme(c *Context, w http.ResponseWriter, r *http.Request) {
+	c.RequireChannelId()
+	if c.Err != nil {
+		return
+	}
+
+	schemeID := model.SchemeIDFromJson(r.Body)
+	if schemeID == nil || len(*schemeID) != 26 {
+		c.SetInvalidParam("scheme_id")
+		return
+	}
+
+	if c.App.License() == nil {
+		c.Err = model.NewAppError("Api4.UpdateChannelScheme", "api.channel.update_channel_scheme.license.error", nil, "", http.StatusNotImplemented)
+		return
+	}
+
+	if !c.App.SessionHasPermissionToChannel(c.Session, c.Params.ChannelId, model.PERMISSION_MANAGE_SYSTEM) {
+		c.SetPermissionError(model.PERMISSION_MANAGE_SYSTEM)
+		return
+	}
+
+	scheme, err := c.App.GetScheme(*schemeID)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	if scheme.Scope != model.SCHEME_SCOPE_CHANNEL {
+		c.Err = model.NewAppError("Api4.UpdateChannelScheme", "api.channel.update_channel_scheme.scheme_scope.error", nil, "", http.StatusBadRequest)
+		return
+	}
+
+	channel, err := c.App.GetChannel(c.Params.ChannelId)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	channel.SchemeId = &scheme.Id
+
+	_, err = c.App.UpdateChannelScheme(channel)
+	if err != nil {
+		c.Err = err
+		return
+	}
+
+	ReturnStatusOK(w)
+}