import SwiftUI
import WaterfallGrid

struct PostGridView: View {
  @EnvironmentObject var settings: Settings
  @EnvironmentObject var manager: BooruManager

  @Environment(\.isSearching)
  private var isSearching

  var filteredPosts: [BooruPost] {
    manager.posts.filter { settings.displayRatings.contains($0.rating) }
      .sorted { $0.id > $1.id }
  }

  var body: some View {
    ScrollViewReader { _ in
      ScrollView {
        if filteredPosts.isEmpty {
          ProgressView()
            .padding()
        }

        WaterfallGrid(filteredPosts, id: \.id) { post in
          Button {
            manager.selectedPost = post
          } label: {
            PostGridThumbnailView(
              post: post,
              posts: filteredPosts
            )
          }
          .buttonStyle(PlainButtonStyle())
          .contextMenu {
            Button(action: { manager.selectedPost = post }) {
              Label("Select Post", systemImage: "arrow.right.circle")
            }
          }
        }
        .gridStyle(columns: settings.columns)
        .padding(8)
      }
      .searchable(text: $manager.searchText, prompt: "Tags")
      .searchSuggestions {
        if settings.searchSuggestions {
          SearchSuggestionsView(
            tags: manager.allTags,
            searchText: $manager.searchText
          )
        }
      }
      .onSubmit(of: .search, manager.performSearch)
      .navigationDestination(for: BooruPost.self) { post in
        PostDetailsView(post: post)
      }
      .onChange(of: manager.searchText) { _, _ in
        if manager.searchText.isEmpty, !isSearching {
          Task { manager.performSearch() }
        }
      }
      .toolbar {
        #if os(macOS)
          ToolbarItem {
            Button(action: {
              Task {
                await manager.fetchPosts(page: 1, tags: manager.tags, replace: true)
              }
            }) {
              Label("Refresh", systemImage: "arrow.clockwise")
            }
            .disabled(manager.isLoading)
          }
        #endif

        #if os(macOS)
          ToolbarItem {
            Button(action: { Task { manager.loadNextPage() } }) {
              Label("Manually Load Next Page", systemImage: "chevron.right")
            }
            .disabled(manager.isLoading)
          }
        #else
          ToolbarItem(placement: .bottomBar) {
            Button(action: { Task { manager.loadNextPage() } }) {
              Label("Manually Load Next Page", systemImage: "chevron.right")
            }
            .disabled(manager.isLoading)
          }
        #endif

        if !manager.tags.isEmpty {
          #if os(macOS)
            ToolbarItem { PostGridBookmarkButtonView() }
          #else
            ToolbarItem(placement: .bottomBar) { PostGridBookmarkButtonView() }
          #endif
        }
      }
      .navigationTitle("Posts")
      .refreshable {
        await manager.fetchPosts(page: 1, tags: manager.tags, replace: true)
      }
    }
  }
}