swiftui-multiplatform/Shared/PostList/PostListView.swift

import SwiftUI

struct PostListView: View {
    @EnvironmentObject var model: WriteFreelyModel
    @Environment(\.managedObjectContext) var moc

    @State var selectedCollection: WFACollection?
    @State var showAllPosts: Bool = false

    var body: some View {
        #if os(iOS)
        GeometryReader { geometry in
            PostListFilteredView(filter: selectedCollection?.alias, showAllPosts: showAllPosts)
            .navigationTitle(
                showAllPosts ? "All Posts" : selectedCollection?.title ?? (
                    model.account.server == "https://write.as" ? "Anonymous" : "Drafts"
                )
            )
            .toolbar {
                ToolbarItem(placement: .primaryAction) {
                    Button(action: {
                        createNewLocalDraft()
                    }, label: {
                        Image(systemName: "square.and.pencil")
                    })
                }
                ToolbarItem(placement: .bottomBar) {
                    HStack {
                        Button(action: {
                            model.isPresentingSettingsView = true
                        }, label: {
                            Image(systemName: "gear")
                        })
                        .padding(.leading)
                        Spacer()
                        Text(pluralizedPostCount(for: showPosts(for: selectedCollection)))
                            .foregroundColor(.secondary)
                        Spacer()
                        Button(action: {
                            reloadFromServer()
                        }, label: {
                            Image(systemName: "arrow.clockwise")
                        })
                        .disabled(!model.account.isLoggedIn)
                    }
                    .padding()
                    .frame(width: geometry.size.width)
                }
            }
        }
        #else //if os(macOS)
        PostListFilteredView(filter: selectedCollection?.alias, showAllPosts: showAllPosts)
        .navigationTitle(
            showAllPosts ? "All Posts" : selectedCollection?.title ?? (
                model.account.server == "https://write.as" ? "Anonymous" : "Drafts"
            )
        )
        .navigationSubtitle(pluralizedPostCount(for: showPosts(for: selectedCollection)))
        .toolbar {
            Button(action: {
                createNewLocalDraft()
            }, label: {
                Image(systemName: "square.and.pencil")
            })
            Button(action: {
                reloadFromServer()
            }, label: {
                Image(systemName: "arrow.clockwise")
            })
            .disabled(!model.account.isLoggedIn)
        }
        #endif
    }

    private func pluralizedPostCount(for posts: [WFAPost]) -> String {
        if posts.count == 1 {
            return "1 post"
        } else {
            return "\(posts.count) posts"
        }
    }

    private func showPosts(for collection: WFACollection?) -> [WFAPost] {
        if showAllPosts {
            return model.posts.userPosts
        } else {
            if let selectedCollection = collection {
                return model.posts.userPosts.filter { $0.collectionAlias == selectedCollection.alias }
            } else {
                return model.posts.userPosts.filter { $0.collectionAlias == nil }
            }
        }
    }

    private func reloadFromServer() {
        DispatchQueue.main.async {
            model.fetchUserCollections()
            model.fetchUserPosts()
        }
    }

    private func createNewLocalDraft() {
        let managedPost = WFAPost(context: LocalStorageManager.persistentContainer.viewContext)
        managedPost.createdDate = Date()
        managedPost.title = ""
        managedPost.body = ""
        managedPost.status = PostStatus.local.rawValue
        if let selectedCollectionAlias = selectedCollection?.alias {
            managedPost.collectionAlias = selectedCollectionAlias
        }
        DispatchQueue.main.async {
            LocalStorageManager().saveContext()
        }
    }
}

struct PostListView_Previews: PreviewProvider {
    static var previews: some View {
        let context = LocalStorageManager.persistentContainer.viewContext
        let model = WriteFreelyModel()

        return PostListView()
            .environment(\.managedObjectContext, context)
            .environmentObject(model)
    }
}