import SwiftUI

// MARK: - Skeleton loading row

private struct SkeletonRow: View {
    var delay: Double = 0
    @State private var dimmed = false

    var body: some View {
        HStack(alignment: .top, spacing: 11) {
            RoundedRectangle(cornerRadius: 7)
                .fill(Color(.systemGray5))
                .frame(width: 32, height: 32)
            VStack(alignment: .leading, spacing: 7) {
                Capsule()
                    .fill(Color(.systemGray5))
                    .frame(maxWidth: .infinity)
                    .frame(height: 13)
                Capsule()
                    .fill(Color(.systemGray6))
                    .frame(width: 140, height: 10)
            }
            .padding(.top, 4)
            Spacer()
        }
        .padding(.vertical, 14)
        .opacity(dimmed ? 0.45 : 1)
        .onAppear {
            withAnimation(
                .easeInOut(duration: 0.9)
                .repeatForever(autoreverses: true)
                .delay(delay)
            ) { dimmed = true }
        }
    }
}

// MARK: - Row press ButtonStyle

struct RowPressStyle: ButtonStyle {
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .scaleEffect(configuration.isPressed ? 0.97 : 1)
            .opacity(configuration.isPressed ? 0.75 : 1)
            .animation(.spring(duration: 0.18, bounce: 0), value: configuration.isPressed)
    }
}

// MARK: - BookmarksView

struct BookmarksView: View {
    @Bindable var viewModel: BookmarksViewModel
    let onDisconnect: () -> Void

    @State private var showSettings = false
    @State private var showCollections = false
    @State private var showAddBookmark = false
    @State private var editingBookmark: Bookmark?
    @State private var browsingBookmark: Bookmark?
    @State private var showFullPlayer = false
    @State private var showPodcastLibrary = false
    @State private var showAsk = false
    @State private var readingProgress: [String: Double] = ReadingProgress.all()

    var body: some View {
        NavigationStack {
            List {
                if viewModel.isLoading && viewModel.bookmarks.isEmpty {
                    ForEach(0..<3, id: \.self) { i in
                        SkeletonRow(delay: Double(i) * 0.13)
                            .listRowInsets(EdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16))
                            .listRowSeparator(.visible)
                    }
                } else {
                    ForEach(viewModel.bookmarks) { bookmark in
                        BookmarkListRow(
                            bookmark: bookmark,
                            viewModel: viewModel,
                            readingProgress: readingProgress[bookmark.url] ?? 0,
                            onOpen: { browsingBookmark = bookmark },
                            onEdit: { editingBookmark = bookmark }
                        )
                        .onAppear { maybeLoadMore(bookmark) }
                    }
                }

                if viewModel.isLoadingMore {
                    HStack { Spacer(); ProgressView(); Spacer() }
                        .listRowSeparator(.hidden)
                }
            }
            .listStyle(.plain)
            .animation(.spring(duration: 0.35), value: viewModel.bookmarks.isEmpty)
            .navigationTitle(viewModel.unreadFilter ? "Unread" : "Bookmarks")
            .navigationBarTitleDisplayMode(.large)
            .toolbar {
                ToolbarItem(placement: .topBarLeading) {
                    Menu {
                        Button {
                            showAsk = true
                        } label: {
                            Label("Ask Your Bookmarks", systemImage: "bubble.left.and.text.bubble.right")
                        }
                        Button {
                            Task { await viewModel.generateSmartCollections() }
                            showCollections = true
                        } label: {
                            Label("Smart Collections", systemImage: "sparkles")
                        }
                        Button {
                            Task { await viewModel.enrichAll() }
                        } label: {
                            Label("Enrich All with AI", systemImage: "wand.and.stars")
                        }
                        Button {
                            showPodcastLibrary = true
                        } label: {
                            Label("Podcasts", systemImage: "headphones")
                        }
                    } label: {
                        Image(systemName: "sparkles")
                    }
                }
                ToolbarItem(placement: .topBarTrailing) {
                    HStack(spacing: 16) {
                        Button { showAddBookmark = true } label: {
                            Image(systemName: "plus")
                        }
                        Button {
                            Task { await viewModel.toggleUnreadFilter() }
                        } label: {
                            Image(systemName: viewModel.unreadFilter
                                  ? "line.3.horizontal.decrease.circle.fill"
                                  : "line.3.horizontal.decrease.circle")
                                .contentTransition(.symbolEffect(.replace))
                        }
                        Button { showSettings = true } label: {
                            Image(systemName: "gearshape")
                        }
                    }
                }
            }
            .overlay {
                if !viewModel.isLoading && viewModel.bookmarks.isEmpty {
                    ContentUnavailableView(
                        "No Bookmarks",
                        systemImage: "bookmark",
                        description: Text("Bookmarks you save will appear here.")
                    )
                    .transition(.opacity)
                }
            }
            .overlay(alignment: .bottom) {
                VStack(spacing: 8) {
                    if !viewModel.podcastPlayer.currentArticleUrl.isEmpty {
                        MiniPlayerView(vm: viewModel.podcastPlayer) {
                            showFullPlayer = true
                        }
                        .transition(.move(edge: .bottom).combined(with: .opacity))
                    }
                    if viewModel.enrichmentProgress > 0 {
                        enrichmentBanner
                    }
                }
                .animation(.spring(duration: 0.3), value: !viewModel.podcastPlayer.currentArticleUrl.isEmpty)
                .padding(.bottom, 8)
            }
            .sensoryFeedback(.selection, trigger: browsingBookmark?.id)
        }
        .sheet(isPresented: $showSettings) {
            SettingsView(viewModel: viewModel, onDisconnect: onDisconnect)
        }
        .sheet(isPresented: $showCollections) {
            CollectionsView(viewModel: viewModel)
        }
        .sheet(isPresented: $showAsk) {
            AskView()
        }
        .sheet(isPresented: $showAddBookmark) {
            AddBookmarkView(viewModel: viewModel)
        }
        .sheet(item: $editingBookmark) { bookmark in
            EditBookmarkView(viewModel: viewModel, bookmark: bookmark)
        }
        .sheet(item: $browsingBookmark) { bookmark in
            if let url = URL(string: bookmark.url) {
                BrowserView(url: url, title: bookmark.displayTitle, claude: viewModel.claude, podcastPlayer: viewModel.podcastPlayer) {
                    await viewModel.archive(bookmark)
                }
                .bookmarkOnscreen(bookmark)
            }
        }
        .onChange(of: browsingBookmark) { _, new in
            if new == nil { readingProgress = ReadingProgress.all() }
        }
        .sheet(isPresented: $showFullPlayer) {
            PodcastPlayerView(
                vm: viewModel.podcastPlayer,
                articleUrl: viewModel.podcastPlayer.currentArticleUrl,
                articleTitle: viewModel.podcastPlayer.currentArticleTitle,
                claude: viewModel.claude,
                stopOnDismiss: false
            )
        }
        .sheet(isPresented: $showPodcastLibrary) {
            PodcastLibraryView(vm: viewModel.podcastPlayer, claude: viewModel.claude)
        }
        .refreshable {
            await viewModel.load()
        }
        .task {
            if viewModel.bookmarks.isEmpty {
                await viewModel.load()
            }
        }
        .alert("Error", isPresented: Binding(
            get: { viewModel.error != nil },
            set: { if !$0 { viewModel.error = nil } }
        )) {
            Button("OK") { viewModel.error = nil }
        } message: {
            Text(viewModel.error ?? "")
        }
    }

    private var enrichmentBanner: some View {
        HStack(spacing: 10) {
            ProgressView(value: viewModel.enrichmentProgress)
                .progressViewStyle(.linear)
                .tint(.primary)
            Text("Adding AI summaries…")
                .font(.system(size: 13))
                .foregroundStyle(.secondary)
        }
        .padding(.horizontal, 20)
        .padding(.vertical, 12)
        .background(.regularMaterial)
        .clipShape(RoundedRectangle(cornerRadius: 12))
        .padding(.horizontal, 16)
    }

    private func maybeLoadMore(_ bookmark: Bookmark) {
        guard let last = viewModel.bookmarks.last, last.id == bookmark.id,
              viewModel.nextPageUrl != nil, !viewModel.isLoadingMore else { return }
        Task { await viewModel.loadMore() }
    }
}