Prototype with Xcode Playgrounds

2:04 - birdsToShow computed property before the required changes

var birdsToShow: [Bird] {
    // TODO: Narrow down the list of birds to find.
    let birdProvider = BirdProvider(region: .northAmerica)
    return birdProvider.birds
}

4:15 - birdProvider instance

let birdProvider = BirdProvider(region: .northAmerica)

6:31 - CustomStringConvertible

extension Bird: CustomStringConvertible {
    
    public var description: String {
        return "\(commonName) (\(scientificName))"
    }
    
}

8:17 - CustomPlaygroundDisplayConvertible

extension Bird: CustomPlaygroundDisplayConvertible {
    
    public var playgroundDescription: Any {
        return photo as Any
    }
    
}

9:45 - Birds without a photo

let birdsToFind = birdProvider.birds.filter { $0.photo == nil }

10:52 - Owls without a photo

let owlsToFind = birdsToFind.filter { $0.family == .owls }

11:15 - Verifying the ChecklistView

let checklist = ChecklistView()
for bird in owlsToFind {
    checklist.add(bird)
}

13:41 - birdsToShow computed property with the required changes

var birdsToShow: [Bird] {
    let birdProvider = BirdProvider(region: .northAmerica)
    let birdsToFind = birdProvider.birds.filter { $0.photo == nil }
    let owlsToFind = birdsToFind.filter { $0.family == .owls }
    return owlsToFind
}

14:21 - sightingToShow function before the required changes

func sightingToShow(for bird: Bird) -> Sighting? {
    // TODO: Use BirdSightings package to fetch the most recent sighting.
    return nil
}

15:04 - BirdSightings package example

let barnOwlCode = "BNOW"
let centralParkLocation = CLLocationCoordinate2D(latitude:  40.785091, longitude: -73.968285)

let sightingsProvider = SightingsProvider()
sightingsProvider.fetchSightings(of: barnOwlCode, around: centralParkLocation)

16:08 - Parameters for sightings fetching

let bird = owlsToFind.first!
let appleParkLocation = CLLocationCoordinate2D(latitude: 37.3348655, longitude: 122.0089409)

17:31 - Sightings fetching

let sightingsProvider = SightingsProvider()
let sightings = sightingsProvider.fetchSightings(of: bird.speciesCode, around: appleParkLocation)

18:23 - Initializing the SightingMapView

let mostRecentSighting = sightings.first
let sightingMapView = SightingMapView(sighting: mostRecentSighting)

18:55 - Setting up the playground's live view

import PlaygroundSupport
PlaygroundPage.current.liveView = sightingMapView

22:20 - sightingToShow function with the required changes

func sightingToShow(for bird: Bird) -> Sighting? {
    let sightingsProvider = SightingsProvider()
    let sightings = sightingsProvider.fetchSightings(of: bird.speciesCode, around: lastCurrentLocation)
    let mostRecentSighting = sightings.first
    return mostRecentSighting
}