import SwiftUI

struct MainView: View {
    @EnvironmentObject var settings: Settings
    @State private var selectedTab: Int = 0
    @State private var manager = BooruManager(.yandere)

    var body: some View {
        platformSpecificContent
            .environmentObject(settings)
            .environmentObject(manager)
            .onChange(of: settings.preferredBooru) { _, newState in
                updateManager(newState)
            }
            .onAppear(perform: initialiseManager)
    }

    @ViewBuilder
    private var platformSpecificContent: some View {
        #if os(macOS)
            ContentView()
        #else
            TabView(selection: $selectedTab) {
                ContentView()
                    .tabItem { Label("Posts", systemImage: "rectangle.stack") }
                    .tag(0)

                NavigationStack {
                    BookmarksView(selectedTab: $selectedTab)
                }
                .tabItem { Label("Bookmarks", systemImage: "bookmark") }
                .tag(1)

                NavigationStack {
                    SettingsView()
                }
                .tabItem { Label("Settings", systemImage: "gear") }
                .tag(2)
            }
        #endif
    }

    private func updateManager(_ provider: BooruProvider) {
        let previousSearchText = manager.searchText

        manager = BooruManager(provider)
        manager.searchText = previousSearchText

        Task {
            if self.manager.searchText.isEmpty {
                await self.manager.fetchPosts()
            } else {
                self.manager.performSearch()
            }
        }
    }

    private func initialiseManager() {
        manager = BooruManager(settings.preferredBooru)

        Task {
            if manager.posts.isEmpty {
                await manager.fetchPosts()
            }
        }
    }
}