import SwiftUI

/// The native interface: feeds beside items, with the player bar under both.
///
/// What is not here yet has somewhere to go rather than being missing. The item pane is #4 and
/// the management screens are #5; until then the toolbar's Page button opens ipx's own page,
/// which is still the whole app in a web view and can do everything this cannot.
struct LibraryView: View {
    @ObservedObject var store: LibraryStore
    @ObservedObject var playback: Playback
    /// The file is the one asked for, or the item's first playable one.
    var play: (IPX.Entry, IPX.Enclosure?) -> Void
    var openPage: (WebViewController.Screen) -> Void
    @ObservedObject var keys: RootViewController.Flag
    @ObservedObject var sidebar: RootViewController.Flag

    /// Everything that lives in the page, named rather than hidden behind one button: it should
    /// be as easy to reach Settings here as it is in a browser.
    private var pageMenu: some View {
        Menu {
            Button { openPage(.settings) } label: { Label("Settings", systemImage: "gearshape") }
            Button { openPage(.directory) } label: { Label("Directory", systemImage: "square.grid.2x2") }
            Button { openPage(.popular) } label: { Label("Popular", systemImage: "star") }
            Button { openPage(.opml) } label: { Label("Import or export OPML", systemImage: "square.and.arrow.up") }
            if store.isAdmin {
                Divider()
                Button { openPage(.admin) } label: { Label("Admin", systemImage: "wrench.and.screwdriver") }
            }
            Divider()
            Button { openPage(.page) } label: { Label("Open the full page", systemImage: "safari") }
        } label: {
            Image(systemName: "ellipsis.circle")
        }
        .accessibilityLabel("More")
        .help("Settings, the directory, OPML")
    }

    @Environment(\.horizontalSizeClass) private var width
    private var wide: Bool { width != .compact }

    var body: some View {
        NavigationSplitView(columnVisibility: Binding(
            get: { sidebar.on ? .detailOnly : .all },
            set: { sidebar.on = $0 == .detailOnly })) {
            FeedListView(store: store)
        } detail: {
            // Wide enough for the page's own three-pane arrangement, or the phone's one-at-a-
            // time. The page draws the same line at 820px and hides its columns below it.
            Group {
                if wide {
                    ContentPaneView(store: store, playback: playback, play: play)
                } else {
                    ItemListView(store: store, playback: playback, play: play)
                }
            }
            .toolbar { ToolbarItem(placement: .primaryAction) { pageMenu } }
        }
        // The wash belongs to the window, once. A copy behind each pane met at the split and
        // the join showed as a seam straight down the middle.
        .background(Glass.Wash())
        .tint(Glass.accent)
        .navigationSplitViewColumnWidth(min: 200, ideal: 260)
        .sheet(isPresented: $keys.on) { KeysView() }
        .alert("That did not save",
               isPresented: Binding(get: { store.problem != nil },
                                    set: { if !$0 { store.problem = nil } })) {
            Button("OK", role: .cancel) { store.problem = nil }
        } message: {
            Text(store.problem ?? "")
        }
        .task {
            await store.refreshFeeds()
            store.reload()
        }
        .safeAreaInset(edge: .bottom, spacing: 0) {
            PlayerBarView(playback: playback)
        }
    }
}