import Defaults
import Siesta
import SwiftUI

struct FeedView: View {
    @ObservedObject private var feed = FeedModel.shared
    @ObservedObject private var accounts = AccountsModel.shared

    @Default(.showCacheStatus) private var showCacheStatus

    #if os(tvOS)
        @Default(.subscriptionsListingStyle) private var subscriptionsListingStyle
    #endif

    var videos: [ContentItem] {
        ContentItem.array(of: feed.videos)
    }

    var body: some View {
        VerticalCells(items: videos) {
            HStack {
                #if os(tvOS)
                    SubscriptionsPageButton()
                    ListingStyleButtons(listingStyle: $subscriptionsListingStyle)
                #endif

                if showCacheStatus {
                    Spacer()

                    CacheStatusHeader(
                        refreshTime: feed.formattedFeedTime,
                        isLoading: feed.isLoading
                    )
                }

                #if os(tvOS)
                    if !showCacheStatus {
                        Spacer()
                    }
                    Button {
                        feed.loadResources(force: true)
                    } label: {
                        Label("Refresh", systemImage: "arrow.clockwise")
                            .labelStyle(.iconOnly)
                            .imageScale(.small)
                            .font(.caption2)
                    }
                #endif
            }
            .padding(.leading, 30)
            #if os(tvOS)
                .padding(.bottom, 15)
            #endif
        }
        .environment(\.loadMoreContentHandler) { feed.loadNextPage() }
        .onAppear {
            feed.loadResources()
        }
        .onChange(of: accounts.current) { _ in
            feed.reset()
            feed.loadResources(force: true)
        }
        #if os(iOS)
        .refreshControl { refreshControl in
            feed.loadResources(force: true) {
                refreshControl.endRefreshing()
            }
        }
        .backport
        .refreshable {
            await feed.loadResources(force: true)
        }
        #endif
        #if !os(tvOS)
        .background(
            Button("Refresh") {
                feed.loadResources(force: true)
            }
            .keyboardShortcut("r")
            .opacity(0)
        )
        #endif
        #if !os(macOS)
        .onReceive(NotificationCenter.default.publisher(for: UIApplication.willEnterForegroundNotification)) { _ in
            feed.loadResources()
        }
        #endif
    }
}

struct SubscriptonsView_Previews: PreviewProvider {
    static var previews: some View {
        NavigationView {
            FeedView()
        }
    }
}