Imagine you're making a theatre booking system, where groups can reserve tickets in blocks. Lots of people are reserving tickets both individually and in groups

Imagine you're making a theatre booking system, where groups can reserve tickets in blocks. Lots of people are reserving tickets both individually and in groups at a time. How do you enforce that groups are mostly booked together? What about if there's a contiguous block when they start purchasing but then some other individuals want one of those seats before the group finishes purchasing? What if one person in the group needs to cancel: do you pick a seat in the middle and let an individual "split" an existing group block, or do you pick one off the edge and shuffle the seats? Does that changed if the group spans two rows? Do any of these decisions change if the tickets are "family" tickets instead of "group" tickets? What if some of the individual tickets are for "floating" tickets and not strictly assigned seats? What about wheelchair accessible seats? Whatever things you end up deciding, does your system, where many people are reserving, cancelling, and re-reserving over long periods of time, guarantee all of the client's expectations?