import Siesta
import SwiftUI

struct TrendingView: View {
    @State private var category: TrendingCategory = .default
    @State private var country: Country = .pl
    @State private var selectingCountry = false

    @ObservedObject private var store = Store<[Video]>()

    var resource: Resource {
        InvidiousAPI.shared.trending(category: category, country: country)
    }

    init() {
        resource.addObserver(store)
    }

    var body: some View {
        Section {
            VStack(alignment: .center, spacing: 2) {
                #if os(tvOS)
                    HStack {
                        Text("Category")
                            .foregroundColor(.secondary)

                        categoryButton

                        Text("Country")
                            .foregroundColor(.secondary)

                        countryFlag
                        countryButton
                    }
                    .scaleEffect(0.85)
                #endif

                VideosView(videos: store.collection)
            }
        }
        #if !os(tvOS)
            .navigationTitle("Trending")
        #endif
        .onAppear {
            resource.loadIfNeeded()
        }
    }

    var categoryButton: some View {
        Button(category.name) {
            setCategory(category.next())
        }
        .contextMenu {
            ForEach(TrendingCategory.allCases) { category in
                Button(category.name) { setCategory(category) }
            }
        }
    }

    var countryFlag: some View {
        Text(country.flag)
            .font(.system(size: 60))
    }

    var countryButton: some View {
        Button(country.rawValue) {
            selectingCountry.toggle()
            resource.removeObservers(ownedBy: store)
        }
        #if os(tvOS)
            .fullScreenCover(isPresented: $selectingCountry, onDismiss: { setCountry(country) }) {
                TrendingCountrySelectionView(selectedCountry: $country)
            }
        #endif
    }

    fileprivate func setCategory(_ category: TrendingCategory) {
        resource.removeObservers(ownedBy: store)
        self.category = category
        resource.addObserver(store)
        resource.loadIfNeeded()
    }

    fileprivate func setCountry(_ country: Country) {
        self.country = country
        resource.addObserver(store)
        resource.loadIfNeeded()
    }
}