import Defaults
import SwiftUI

struct Sidebar: View {
    @EnvironmentObject<AccountsModel> private var accounts
    @EnvironmentObject<NavigationModel> private var navigation

    @Default(.visibleSections) private var visibleSections

    var body: some View {
        ScrollViewReader { scrollView in
            List {
                mainNavigationLinks

                if !accounts.isEmpty {
                    AppSidebarRecents()
                        .id("recentlyOpened")

                    if accounts.api.signedIn {
                        if visibleSections.contains(.subscriptions), accounts.app.supportsSubscriptions {
                            AppSidebarSubscriptions()
                        }

                        if visibleSections.contains(.playlists), accounts.app.supportsUserPlaylists {
                            AppSidebarPlaylists()
                        }
                    }
                }
            }
            .onChange(of: navigation.sidebarSectionChanged) { _ in
                scrollScrollViewToItem(scrollView: scrollView, for: navigation.tabSelection)
            }
            .listStyle(.sidebar)
        }
        .navigationTitle("Yattee")
        #if os(iOS)
            .navigationBarTitleDisplayMode(.inline)
        #endif
    }

    var mainNavigationLinks: some View {
        Section(header: Text("Videos")) {
            if visibleSections.contains(.home) {
                NavigationLink(destination: LazyView(HomeView()), tag: TabSelection.home, selection: $navigation.tabSelection) {
                    Label("Home", systemImage: "house")
                        .accessibility(label: Text("Home"))
                }
                .id("favorites")
            }
            if visibleSections.contains(.subscriptions),
               accounts.app.supportsSubscriptions && accounts.signedIn
            {
                NavigationLink(destination: LazyView(SubscriptionsView()), tag: TabSelection.subscriptions, selection: $navigation.tabSelection) {
                    Label("Subscriptions", systemImage: "star.circle")
                        .accessibility(label: Text("Subscriptions"))
                }
                .id("subscriptions")
            }

            if visibleSections.contains(.popular), accounts.app.supportsPopular {
                NavigationLink(destination: LazyView(PopularView()), tag: TabSelection.popular, selection: $navigation.tabSelection) {
                    Label("Popular", systemImage: "arrow.up.right.circle")
                        .accessibility(label: Text("Popular"))
                }
                .id("popular")
            }

            if visibleSections.contains(.trending) {
                NavigationLink(destination: LazyView(TrendingView()), tag: TabSelection.trending, selection: $navigation.tabSelection) {
                    Label("Trending", systemImage: "chart.bar")
                        .accessibility(label: Text("Trending"))
                }
                .id("trending")
            }

            NavigationLink(destination: LazyView(SearchView()), tag: TabSelection.search, selection: $navigation.tabSelection) {
                Label("Search", systemImage: "magnifyingglass")
                    .accessibility(label: Text("Search"))
            }
            .id("search")
            .keyboardShortcut("f")
        }
    }

    private func scrollScrollViewToItem(scrollView: ScrollViewProxy, for selection: TabSelection) {
        if case .recentlyOpened = selection {
            scrollView.scrollTo("recentlyOpened")
            return
        } else if case let .playlist(id) = selection {
            scrollView.scrollTo(id)
            return
        }

        scrollView.scrollTo(selection.stringValue)
    }
}