uploadAudio() sometimes doesn't execute properly

[dylman123]

The app gets stuck at the semaphore.wait() line.

Intermittent. Probably something to do with threads.

[dylman123]

Need to move away from the semaphore pattern. Look at using Combine's observable objects to manage the state of the backend flow.

Also need to use the @escaping closure for the uploadAudio function. May require nested closures. But this is OK. Although maybe Combine can avoid the need for nested closures...?

[dylman123]

Plan to refactor backend functions

Ok, plan is: Use Jonny's enum state concept to define the following states for each function in the serialised generateCaptions() function:

1. idle
2. ready
3. executing
4. completed
5. failed

• All functions must be idle by default.
• Ensure that each function only begins to execute when in the ready state.
• Any function in executing must update the progress bar status (for the UI).
• A function must ONLY become ready when it receives a signal that the function immediately before it has become completed.
• If any function is failed, then the parent function should be returned from and an error displayed to the user.
• Encapsulate the entire function pipeline in a computed property which returns type AnyView (see Jonny's UserView.swift line 19). This view should be called in the view's body once the user imports a video file successfully.

[dylman123]

[dylman123]

Or maybe the states should simply be:

1. extractAudio
2. convertAudio
3. uploadAudio
4. downloadCaptions
5. deleteTempDir

[dylman123]

Look at how to convert JSON payload into custom struct type with modifications: https://www.hackingwithswift.com/example-code/system/how-to-parse-json-using-jsonserialization

[dylman123]

Implemented Jonny's UserAPI state-based enums. Also needed to use recursion for short polling the server whilst waiting for transcriptions to finish. Will later need to open an issue to build a "silent notification" service to replace the short polling.