import SwiftUI
import SFSafeSymbols

#warning("Fix podcast")
#warning("Allow selection of pages as navigation bar items")
#warning("Add link to other language")
#warning("Transfer images of posts to other language")
#warning("Show tag selection view for pages")
#warning("Button to replace files")
#warning("Replace links to files inside pages when id changes")
#warning("Calculate file sizes")
#warning("Specify image aspect ratio to prevent page jumps")

@main
struct MainView: App {

    private let sidebarWidth: CGFloat = 250

    private let detailWidth: CGFloat = 300

    @StateObject
    private var content: Content = .init()

    @State
    private var language: ContentLanguage = .english

    @State
    private var selectedTab: MainViewTab = .posts

    @State
    private var selectedPost: Post?

    @State
    private var selectedPage: Page?

    @State
    private var selectedTag: Tag?

    @State
    private var selectedImage: ImageResource?

    @State
    private var selectedFile: FileResource?

    @State
    private var selectedSection: SettingsSection = .folders

    @State
    private var showAddSheet = false

    @ViewBuilder
    var sidebar: some View {
        switch selectedTab {
        case .posts:
            PostListView(selectedPost: $selectedPost)
        case .pages:
            PageListView(selectedPage: $selectedPage)
        case .tags:
            TagListView(selectedTag: $selectedTag)
        case .files:
            FileListView(selectedFile: $selectedFile)
        case .generation:
            SettingsListView(selectedSection: $selectedSection)
        }
    }

    @ViewBuilder
    var viewContent: some View {
        switch selectedTab {
        case .posts:
            SelectedContentView<PostContentView>(selected: $selectedPost)
        case .pages:
            SelectedContentView<PageContentView>(selected: $selectedPage)
        case .tags:
            SelectedContentView<TagContentView>(selected: $selectedTag)
        case .files:
            SelectedContentView<FileContentView>(selected: $selectedFile)
        case .generation:
            GenerationContentView(selected: $selectedSection)
        }
    }

    @ViewBuilder
    var detail: some View {
        switch selectedTab {
        case .posts:
            SelectedDetailView<PostDetailView>(selected: $selectedPost)
        case .pages:
            SelectedDetailView<PageDetailView>(selected: $selectedPage)
        case .tags:
            SelectedDetailView<TagDetailView>(selected: $selectedTag)
        case .files:
            SelectedDetailView<FileDetailView>(selected: $selectedFile)
        case .generation:
            GenerationDetailView(section: selectedSection)
        }
    }

    @ViewBuilder
    var addItemSheet: some View {
        switch selectedTab {
        case .posts:
            AddPostView(selected: $selectedPost)
        case .pages:
            AddPageView(selected: $selectedPage)
        case .tags:
            AddTagView(selected: $selectedTag)
        case .files:
            AddFileView(selectedImage: $selectedImage, selectedFile: $selectedFile)
        case .generation:
            Text("Not implemented")
        }
    }

    var body: some Scene {
        WindowGroup {
            NavigationSplitView {
                sidebar
                    .toolbar {
                        ToolbarItem(placement: .navigation) {
                            Picker("", selection: $selectedTab) {
                                Text("Posts").tag(MainViewTab.posts)
                                Text("Pages").tag(MainViewTab.pages)
                                Text("Tags").tag(MainViewTab.tags)
                                Text("Files").tag(MainViewTab.files)
                                Text("Generation").tag(MainViewTab.generation)
                            }.pickerStyle(.segmented)
                        }
                    }
                    .navigationSplitViewColumnWidth(min: sidebarWidth, ideal: sidebarWidth, max: sidebarWidth)
                    .toolbar {
                        ToolbarItem(placement: .primaryAction) {
                            Button(action: { showAddSheet = true }) {
                                Label("Add", systemSymbol: .plus)
                            }
                            .disabled(!selectedTab.canAddItems)
                        }
                    }
            } content: {
                viewContent
            } detail: {
                detail
                    .navigationSplitViewColumnWidth(min: detailWidth, ideal: detailWidth, max: detailWidth)
            }
            .toolbar {
                ToolbarItem(placement: .primaryAction) {
                    Picker("", selection: $language) {
                        Text("English")
                            .tag(ContentLanguage.english)
                        Text("German")
                            .tag(ContentLanguage.german)
                    }.pickerStyle(.segmented)
                }
                ToolbarItem(placement: .primaryAction) {
                    Button(action: save) {
                        Text("Save")
                    }
                }
            }
            .navigationTitle("")
            .environment(\.language, language)
            .environmentObject(content)
            .onAppear(perform: loadContent)
            .onReceive(Timer.publish(every: 60.0, on: .main, in: .common).autoconnect()) { _ in
                save()
            }
            .sheet(isPresented: $showAddSheet) {
                addItemSheet
                    .environment(\.language, language)
                    .environmentObject(content)
            }
        }
    }

    private func save() {
        // Save all changed files
        do {
            try content.saveToDisk()
        } catch {
            print("Failed to save content: \(error.localizedDescription)")
        }
    }

    private func loadContent() {
        do {
            try content.loadFromDisk()
        } catch {
            print("Failed to load content: \(error.localizedDescription)")
        }
    }
}