import SwiftUI
import SFSafeSymbols

struct LocalizedPageDetailView: View {

    @ObservedObject
    private var page: LocalizedPage

    init(page: LocalizedPage, showImagePicker: Bool = false) {
        self.page = page
        self.showImagePicker = showImagePicker
        self.newUrlString = page.urlString
    }

    @State
    private var showImagePicker = false

    @State
    private var newUrlString: String

    private let allowedCharactersInPostId = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-")).inverted

    private var idExists: Bool {
        page.content.pages.contains {
            $0.german.urlString == newUrlString
            || $0.english.urlString == newUrlString
        }
    }

    private var containsInvalidCharacters: Bool {
        newUrlString.rangeOfCharacter(from: allowedCharactersInPostId) != nil
    }

    var body: some View {
        VStack(alignment: .leading) {
            HStack {
                TextField("", text: $newUrlString)
                    .textFieldStyle(.roundedBorder)
                Button("Update", action: setNewId)
                .disabled(newUrlString.isEmpty || containsInvalidCharacters || idExists)
            }
            .padding(.bottom)

            Text("Link Preview Title")
                .font(.headline)
            OptionalTextField("", text: $page.linkPreviewTitle,
                              prompt: page.title)
                .textFieldStyle(.roundedBorder)
            .padding(.bottom)

            HStack {
                Text("Link Preview Image")
                    .font(.headline)
                IconButton(symbol: .squareAndPencilCircleFill,
                           size: 22,
                           color: .blue) {
                    showImagePicker = true
                }

                IconButton(symbol: .trashCircleFill,
                           size: 22,
                           color: .red) {
                    page.linkPreviewImage = nil
                }.disabled(page.linkPreviewImage == nil)
                Spacer()
            }

            .buttonStyle(.plain)
            if let image = page.linkPreviewImage {
                image.imageToDisplay
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .frame(maxWidth: 400, maxHeight: 300)
                    .cornerRadius(8)
                Text(image.id)
                    .font(.headline)
            }

            Text("Link Preview Description")
                .font(.headline)
                .padding(.top)
            OptionalDescriptionField(text: $page.linkPreviewDescription)
                .textFieldStyle(.roundedBorder)
                .padding(.bottom)
        }
        .sheet(isPresented: $showImagePicker) {
            ImagePickerView(showImagePicker: $showImagePicker) { image in
                page.linkPreviewImage = image
            }
        }
    }

    private func setNewId() {
        page.urlString = newUrlString
    }
}

#Preview {
    LocalizedPageDetailView(page: .english)
        .environmentObject(Content.mock)
}