🔥 Help Center [Firestore x Combine x SwiftUI x Codable]

HelpCenter.swift

struct HelpdeskArticle: Codable {
    @DocumentID var id: String?
    let title: String
    let content: String
    let locale: String
}

struct HelpdeskView: View {
    @StateObject var viewModel = HelpdeskViewModel()
    
    var body: some View {
        Group {
            if let sections = viewModel.sections {
                if sections.isEmpty {
                    Text("No article available for your language")
                        .foregroundStyle(.secondary)
                } else {
                    List {
                        ForEach(sections) { section in
                            Section {
                                if viewModel.isSectionExpanded(section) {
                                    Text(section.content)
                                }
                            } header: {
                                Button {
                                    viewModel.toggleSection(section)
                                } label: {
                                    HStack {
                                        Text(section.title)
                                            .font(.headline)
                                        Spacer()
                                        Image(systemName: "chevron.right")
                                            .imageScale(.medium)
                                            .rotationEffect(.degrees(viewModel.isSectionExpanded(section) ? 90 : 0))
                                    }
                                }
                            }
                            .foregroundColor(.asset(.midnight))
                        }
                        .listRowSeparator(.hidden)
                    }
                    .listStyle(.plain)
                }
            } else if let error = viewModel.error {
                Text(error.localizedDescription)
                    .foregroundStyle(.secondary)
            } else {
                ProgressView()
            }
        }
        .task {
            await viewModel.fetchArticles()
        }
        .navigationTitle("HELP CENTER")
    }
}

class HelpdeskViewModel: ObservableObject {
    struct Section: Equatable, Identifiable {
        let id: String?
        let title: String
        let content: AttributedString
        
        init(article: HelpdeskArticle) throws {
            self.id = article.id
            self.title = article.title
            self.content = try .init(markdown: article.content)
        }
    }
        
    @Injected var firestoreManager: FirestoreManager
    @Published var sections: [Section]?
    @Published var error: Error?
    @Published var expandedSection: Section?

    @MainActor func fetchArticles() async {
        do {
            guard let languageCode = Locale.current.languageCode else {
                return
            }
            
            sections = try await firestoreManager.helpdesk(for: languageCode)
                .map { try .init(article: $0) }
        } catch {
            self.error = error
        }
    }
    
    func isSectionExpanded(_ section: Section) -> Bool {
        section == expandedSection
    }
    
    func toggleSection(_ section: Section) {
        withAnimation {
            expandedSection = isSectionExpanded(section) ? nil : section
        }
    }
}

protocol FirestoreManagerProtocol {
    func helpdesk(for locale: String) async throws -> [HelpdeskArticle]
}

class FirestoreManager: FirestoreManagerProtocol
    func helpdesk(for locale: String) async throws -> [HelpdeskArticle] {
        try await firestore.collection(.helpdesk)
            .whereField(.locale, isEqualTo: locale)
            .getDocuments()
            .documents.map { try $0.data(as: HelpdeskArticle.self) }
    }
}

fileprivate extension Firestore {
    enum Collection: String {
        case users, helpdesk
    }
    
    func collection(_ collection: Collection) -> CollectionReference {
        self.collection(collection.rawValue)
    }
}

fileprivate extension DocumentReference {
    enum Collection: String {
        case entries
    }
    
    func collection(_ collection: Collection) -> CollectionReference {
        self.collection(collection.rawValue)
    }
}

fileprivate extension Query {
    enum Field: String {
        case locale
    }
    
    func whereField(_ field: Field, isEqualTo value: Any) -> Query {
        self.whereField(field.rawValue, isEqualTo: value)
    }
}

extension Resolver {
    public static func registerFirestoreManager() {
        register { FirestoreManager() }
            .implements(FirestoreManagerProtocol.self)
            .scope(.application)
    }
}