PHP-Ganntview of appintments from CalDav-server

Dear developers, at this time we are looking for a php-script, to connect with a standard caldav-server like nextcloud or SOGo, that generates a view in gantt-format. It should be possible to assign each gantt-row (resource) to a caldav-url. In first step we only want to read appointments from caldav to the php-script. In the second step, it should be possible to add, modify and delete appointments. This appointments are to save at the caldav-server, but we plan to do this in a second project her on freelancer.com. General project specifications: - annotated code - Compatible with php5 and php7 Project tasks: - a configuration for the access data to the CALDAV - server per resource - an output of the calendar data in Gannt view - variable time units (minute, hour, day, week) - presentation of a calendar per resource (presentation one calendar per resource - line) - line - by clicking on an appointment, the appointment details are displayed in an extra window - an output of the calendar data in Gannt view - Variable time units (minute, hour, day, week) - by clicking on an appointment, the appointment details are displayed in an extra window - the CalDav-server could be a nextcloud or SOGo