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)
      }
      .onChange(of: settings.searchSuggestions) { _, newState in
        if newState {
          refreshTags()
        }
      }
      .onAppear(perform: initializeManager)
  }

  @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)

        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 {
      refreshTags()

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

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

    Task {
      refreshTags()

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

  private func refreshTags() {
    if settings.searchSuggestions {
      Task {
        manager.initializeTags()
      }
    } else {
      Task {
        manager.updateTagsCacheSize()
      }
    }
  }
}