import RastrilloApple
import SwiftUI

struct QuickDraft: Codable {
  let calendar_id: Int64
  let title, location, start_local, end_local, tz: String
  let all_day: Bool
  let `repeat`: String
  let attendees: [String]
}
struct QuickPreview: Decodable {
  let draft: QuickDraft
  let when, repeat_label, calendar_name: String
  let assumptions: [String]
}
struct QuickAddView: View {
  let client: NativeHTTP
  @ObservedObject var model: CalendarModel
  @State private var preview: QuickPreview?
  @State private var error = ""
  @State private var parsing = false
  @FocusState private var focused: Bool
  private var requestKey: String { model.zone + "\n" + model.quickText }
  var body: some View {
    ScrollView {
      VStack(alignment: .leading, spacing: 12) {
        TextField("Lunch tomorrow at 1pm for an hour", text: $model.quickText, axis: .vertical)
          .lineLimit(2...4)
          #if os(macOS)
          .textFieldStyle(.plain)
          .padding(10)
          .background(.background, in: RoundedRectangle(cornerRadius: 8))
          .overlay {
            RoundedRectangle(cornerRadius: 8)
              .strokeBorder(focused ? Color.accentColor : Color.secondary.opacity(0.3), lineWidth: 1)
          }
          #else
          .textFieldStyle(.roundedBorder)
          #endif
          .accessibilityLabel("Describe an event").accessibilityIdentifier("quickAddText")
          .focused($focused).disabled(model.quickSaving)
        Text(model.zone.replacingOccurrences(of: "_", with: " ")).font(.footnote).foregroundStyle(.secondary)
        if parsing { ProgressView("Understanding your event…") }
        if let preview {
          VStack(alignment: .leading, spacing: 8) {
            Text(preview.draft.title).font(.headline)
            Label(preview.when, systemImage: "clock")
            Label(preview.calendar_name, systemImage: "calendar")
            if !preview.draft.location.isEmpty { Label(preview.draft.location, systemImage: "mappin") }
            if !preview.repeat_label.isEmpty { Label(preview.repeat_label, systemImage: "repeat") }
            if !preview.draft.attendees.isEmpty {
              Label(preview.draft.attendees.joined(separator: ", "), systemImage: "person.2")
              Text("Attendees are recorded, not invited. No invitations are sent.").font(.footnote)
            }
            ForEach(preview.assumptions, id: \.self) { Text($0).font(.footnote).foregroundStyle(.secondary) }
          }.accessibilityIdentifier("quickAddPreview")
          Button(model.quickSaving ? "Adding…" : "Add event", systemImage: "plus") { save(preview) }
            .buttonStyle(.borderedProminent).disabled(model.quickSaving || parsing)
            .accessibilityIdentifier("quickAddSave").keyboardShortcut(.return, modifiers: .command)
        }
        if !error.isEmpty { Label(error, systemImage: "exclamationmark.circle").foregroundStyle(.red) }
        if !model.quickSavedNotice.isEmpty { Label(model.quickSavedNotice, systemImage: "checkmark.circle").accessibilityIdentifier("quickAddSaved") }
      }.frame(maxWidth: .infinity, alignment: .leading)
    }
    .task(id: requestKey) {
      preview = nil; error = ""
      guard !model.quickText.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else { parsing = false; return }
      parsing = true
      let key = requestKey
      do {
        try await Task.sleep(for: .milliseconds(350))
        let result: QuickPreview = try await client.request("/api/native/quick/parse", method: "POST",
          body: JSONEncoder().encode(["text": model.quickText, "zone": model.zone]))
        guard !Task.isCancelled, requestKey == key else { return }
        preview = result; parsing = false
      } catch {
        guard !Task.isCancelled, requestKey == key else { return }
        self.error = error.localizedDescription; parsing = false
      }
    }
    .onChange(of: model.quickText) { _, text in preview = nil; if !text.isEmpty { model.quickSavedNotice = "" } }
    .onChange(of: model.zone) { _, _ in preview = nil }
  }
  private func save(_ preview: QuickPreview) {
    error = ""
    Task {
      do { try await model.saveQuick(preview, client: client); self.preview = nil }
      catch is CancellationError { }
      catch { self.error = error.localizedDescription }
    }
  }
}