org-social-ios/App/Views/Groups/GroupsView.swift

import SwiftUI
import OrgSocialKit

struct GroupsView: View {
    @State private var viewModel = GroupsViewModel()
    @Environment(\.appTheme) private var theme

    var body: some View {
        NavigationStack {
            Group {
                if viewModel.isLoadingGroups {
                    ProgressView()
                        .frame(maxWidth: .infinity, maxHeight: .infinity)
                } else if let error = viewModel.groupsError {
                    ContentUnavailableView {
                        Label("Groups unavailable", systemImage: "person.3.slash")
                    } description: {
                        Text(error)
                    } actions: {
                        Button("Retry") { Task { await viewModel.loadGroups() } }
                            .buttonStyle(.bordered)
                    }
                } else if viewModel.items.isEmpty {
                    ContentUnavailableView(
                        "No groups",
                        systemImage: "person.3",
                        description: Text("No groups are registered on this relay.")
                    )
                } else {
                    groupList
                }
            }
            .background(theme.background)
            .navigationTitle("Groups")
            .navigationBarTitleDisplayMode(.inline)
            .task { await viewModel.loadGroups() }
            .toolbarBackground(theme.secondaryBackground, for: .navigationBar)
            // Safe navigation: no NavigationLink inside List rows.
            // selectedItem drives the destination to avoid the iOS bug where
            // tapping a Button in a row fires the nearest NavigationLink instead.
            .navigationDestination(item: $viewModel.selectedItem) { item in
                GroupPostsView(item: item, viewModel: viewModel)
            }
            .alert("Error", isPresented: .constant(viewModel.followError != nil)) {
                Button("OK") { viewModel.followError = nil }
            } message: {
                Text(viewModel.followError ?? "")
            }
        }
    }

    private var groupList: some View {
        List(viewModel.items) { item in
            HStack(spacing: 12) {
                // Tap area: navigates to group posts
                Button {
                    viewModel.selectedItem = item
                } label: {
                    HStack(spacing: 10) {
                        Image(systemName: item.slug == nil ? "person.3.slash" : "person.3.fill")
                            .foregroundStyle(item.slug == nil ? .secondary : .primary)
                        VStack(alignment: .leading, spacing: 2) {
                            Text(item.name)
                                .foregroundStyle(.primary)
                            if item.slug == nil {
                                Text("Not on current relay")
                                    .font(.caption)
                                    .foregroundStyle(.secondary)
                            }
                        }
                    }
                    .frame(maxWidth: .infinity, alignment: .leading)
                    .contentShape(Rectangle())
                }
                .buttonStyle(.plain)

                if viewModel.canFollow {
                    followButton(for: item)
                }
            }
            .listRowSeparator(.visible)
            .listRowSeparatorTint(Color.secondary.opacity(0.2))
            .listRowBackground(theme.background)
        }
        .listStyle(.plain)
        .scrollContentBackground(.hidden)
        .background(theme.background)
    }

    @ViewBuilder
    private func followButton(for item: GroupDisplayItem) -> some View {
        let toggling = viewModel.isToggling(item)
        Button {
            Task { await viewModel.toggleFollow(item) }
        } label: {
            if toggling {
                ProgressView()
                    .frame(width: 70, height: 28)
            } else {
                Text(item.isFollowed ? "Unfollow" : "Follow")
                    .font(.subheadline)
                    .fontWeight(item.isFollowed ? .regular : .semibold)
                    .frame(width: 72)
            }
        }
        .buttonStyle(.bordered)
        .tint(item.isFollowed ? .secondary : .accentColor)
        .disabled(toggling)
    }
}

// Alias so the navigation destination closure can refer to the type directly.
private typealias GroupDisplayItem = GroupsViewModel.GroupDisplayItem

private struct GroupPostsView: View {
    let item: GroupDisplayItem
    var viewModel: GroupsViewModel
    @State private var showCompose = false
    @Environment(\.appTheme) private var theme

    var body: some View {
        Group {
            if viewModel.isLoadingPosts {
                ProgressView()
                    .frame(maxWidth: .infinity, maxHeight: .infinity)
            } else if let error = viewModel.postsError {
                ContentUnavailableView {
                    Label("Could not load posts", systemImage: "exclamationmark.triangle")
                } description: {
                    Text(error)
                } actions: {
                    Button("Retry") { Task { await viewModel.loadPosts(for: item) } }
                        .buttonStyle(.bordered)
                }
            } else if viewModel.posts.isEmpty {
                ContentUnavailableView(
                    "No posts",
                    systemImage: "bubble.left.and.bubble.right",
                    description: Text("This group has no posts yet.")
                )
            } else {
                List {
                    ForEach(viewModel.posts, id: \.timestamp) { post in
                        PostRowView(post: post)
                            .listRowSeparator(.visible)
                            .listRowSeparatorTint(Color.secondary.opacity(0.2))
                            .listRowInsets(EdgeInsets(top: 12, leading: 16, bottom: 12, trailing: 16))
                            .listRowBackground(theme.background)
                    }
                }
                .listStyle(.plain)
                .scrollContentBackground(.hidden)
                .background(theme.background)
                .navigationDestination(for: URL.self) { ProfileView(feedURL: $0) }
                .navigationDestination(for: ThreadRoute.self) {
                    ThreadView(postURL: $0.postURL, relayURL: $0.relayURL)
                }
            }
        }
        .background(theme.background)
        .navigationTitle(item.name)
        .navigationBarTitleDisplayMode(.inline)
        .toolbarBackground(theme.secondaryBackground, for: .navigationBar)
        .toolbar {
            ToolbarItem(placement: .navigationBarTrailing) {
                Button { showCompose = true } label: {
                    Image(systemName: "square.and.pencil")
                }
                .accessibilityLabel("Compose")
            }
        }
        .sheet(isPresented: $showCompose) {
            let relayBase = UserDefaults.standard.string(forKey: "relayURL") ?? "https://relay.org-social.org"
            ComposeView(group: "\(item.name) \(relayBase)")
        }
        .task { await viewModel.loadPosts(for: item) }
    }
}