Changing static var embedded in an array? - arrays

Question

I have a series of videos for the user to choose from. At any point, I want to be able to access the video property by calling Video.setupFull.watched and find out if it's nil or not. I created a struct and then static variables to create each video.
Here is my setup code:
struct Video {
let name: String
let image: String
let firebaseID: String
let number: Int
let url: String
let desc: String
var playbackTime: TimeInterval?
var watched: Bool?
var watchedDate: TimeInterval?
static let setupFull = Video(name: "Setup Full",
image: "Setup Full",
firebaseID: "setupTutorialFull",
number: 300928943,
url: "https://player.vimeo.com/external/282034045",
desc: "Moneypants Setup Tutorial Full")
static let step1Income = Video(name: "Step 1 - Income",
image: "Step 1 Income",
firebaseID: "step1Income",
number: 282034041,
url: "https://player.vimeo.com/external/282034041",
desc: "Moneypants Setup Tutorial (Step 1) - Income")
static let step2FamilyMembers = Video(name: "Step 2 - Family Members",
image: "Step 2 Family Members",
firebaseID: "step2FamilyMembers",
number: 282600740,
url: "https://player.vimeo.com/external/282600740",
desc: "Moneypants Setup Tutorial (Step 2) - Family Members")
static var array = [setupFull, step1Income, step2FamilyMembers]
}
To save space, I only store the optional parameters of the video objects (playbackTime, the watched, and the watchedDate) on Firebase, which looks like this:
{
"setupTutorialFull" : {
"playbackTime" : 194,
"watched" : true,
"watchedDate" : 1550004207
},
"step1Income" : {
"playbackTime" : 10,
"watched" : true,
"watchedDate" : 1544566787
},
"step2FamilyMembers" : {
"playbackTime" : 22,
"watched" : true,
"watchedDate" : 1544589461
}
}
(Note that all the videos in the list have been watched.)
I want to do a batch update when I initially load the data, so I made the array of videos and tried to update them like this:
static func observeDB(completion: #escaping () -> Void) {
FB.ref
.child(FB.videos)
.observe(.value) { (snapshot) in
for item in snapshot.children {
guard let snap = item as? DataSnapshot else { return }
guard let value = snap.value as? [String: Any] else { return }
let videoID = snap.key
let playbackTime = value[FB.playbackTime] as? TimeInterval
let watched = value[FB.watched] as? Bool
let watchedDate = value[FB.watchedDate] as? TimeInterval
// Find the appropriate video and update its variables.
if let index = array.firstIndex(where: { $0.firebaseID == videoID }) {
array[index].playbackTime = playbackTime
array[index].watched = watched
array[index].watchedDate = watchedDate
}
}
completion()
}
}
But, to my dismay, the static variables don't update when the array does.
print(Video.setupFull.watched) // prints `nil`
print(Video.array[0].watched) // prints `true`
Now if I manually modify the static var directly, it updates. This is expected, of course.
Video.setupFull.watched = true
print(Video.setupFull.watched) // prints `true`
The problems is I have potentially hundreds of videos to update, though, and don't want to have to manually update each one. That's why I created the static array. That way I could iterate over the array and update the videos quickly. I want to be able to call Video.setupFull.watched on a separate view controller and it to show watched.
My question: Why don't the static variables update when they are embedded in an array? Why can't I use Video.array[0].watched = true and it update the underlying Video.setupFull.watched object?
I thought that was how structs worked. They don't create copies, but are directly modifiable. What am I missing?